Herbal Monograph
Lobelia
Lobelia inflata L.
Campanulaceae (Lobelioideae)
The supreme respiratory antispasmodic of American herbal tradition, cornerstone of Thomsonian medicine, with a...
Overview
Plant Description
Lobelia inflata is an annual or biennial herbaceous plant of the bellflower family, growing 20-100 cm (8-40 inches) in height from a fibrous root system. The erect stem is simple below, branching freely in the upper portion, angular (ridged), and covered with scattered stiff hairs (hirsute). The basal leaves are broadly ovate to spatulate, 3-8 cm long, with irregularly crenate-dentate margins, gradually tapering into a winged petiole. Cauline (stem) leaves become progressively smaller upward, sessile, ovate-lanceolate to lanceolate, alternately arranged, with toothed margins and hairy surfaces. The flowers are produced in loose terminal and axillary racemes. Individual flowers are small (6-8 mm), pale violet-blue to white (sometimes tinged with pink), bilabiate (two-lipped), with the two upper lobes erect and narrow and the three lower lobes spreading, the corolla tube split along the upper side, a characteristic of the genus. Stamens are fused into a tube around the style (synandrous). The most distinctive morphological feature, and the source of the species epithet 'inflata,' is the fruit: an inflated, bladder-like bilocular capsule, 6-10 mm across, nearly globular, prominently ribbed, persistent, and papery at maturity. These inflated seed capsules are diagnostic and make the plant unmistakable in fruit. The seeds are extremely small (less than 0.5 mm), numerous, brown, and reticulate-pitted. The whole plant exudes a milky latex when broken, and chewing the leaf produces a characteristic acrid, burning, tobacco-like sensation on the tongue followed by profuse salivation -- this taste test was a traditional identification method but is inadvisable due to the emetic potential. The plant has a mild, somewhat irritating odor when fresh.
Habitat
Lobelia inflata is native to eastern North America and grows in a wide range of open to semi-shaded habitats, characteristically in disturbed ground, forest edges, roadsides, fallow fields, pastures, meadows, open woodlands, and woodland clearings. It thrives in acidic to neutral soils and is often found in recently logged or burned areas, along old logging roads, and in old fields reverting to forest. It prefers moist but well-drained soils with partial shade to full sun. It is a successional species, colonizing open ground and declining as canopy closure occurs. It grows from near sea level to moderate elevations throughout its range. The plant is considered a common weed of neglected ground across much of eastern North America and can appear in lawns, gardens, and along footpaths.
Distribution
Native to eastern North America, ranging from southeastern Canada (Nova Scotia, New Brunswick, Quebec, Ontario) south through the eastern United States to Georgia, Alabama, Mississippi, and Arkansas, and west to Minnesota, Iowa, Kansas, and eastern Nebraska. It has been introduced and occasionally naturalized in parts of western North America, Europe (particularly the United Kingdom, where it was introduced in the 19th century and briefly cultivated for medicinal purposes), and East Asia. The center of abundance is the Appalachian region and New England states, where it has historically been most intensively collected for the herbal trade. Wild harvesting from Appalachian populations sustained the bulk of commercial supply through the 19th and early 20th centuries.
Parts Used
Aerial parts (herba, flowering tops)
Preferred: Dried cut herb for tincture or vinegar extraction; finely cut herb for infusion (rarely used due to emetic risk at higher doses)
The entire above-ground portion of the plant harvested at the flowering-to-fruiting stage, including stems, leaves, flowers, and developing inflated seed capsules. This is the standard pharmacopeial and commercial drug. Contains the full spectrum of piperidine alkaloids (lobeline, lobelanine, lobelanidine, etc.), with alkaloid concentration varying across plant organs. The aerial herb is the form specified in the British Herbal Pharmacopoeia (BHP 1983), the British Pharmaceutical Codex, and most Western herbal pharmacopeias. Traditionally described as acrid and burning on the tongue, producing copious salivation -- a classic identification test. The BHP monograph specifies 'Lobeliae Herba' as the dried aerial parts collected during the fruiting period.
Seeds (semen)
Preferred: Powdered seed for tincture; crushed seed for vinegar extract (Thomsonian); seed tincture (1:5 in 60% ethanol)
The extremely small, brown, reticulate-pitted seeds harvested from mature inflated capsules. Considered the most concentrated source of piperidine alkaloids, containing approximately 3-4 times the alkaloid concentration of the leafy herb by weight. Thomsonian and Eclectic practitioners specifically valued lobelia seed for preparations requiring maximum potency. Samuel Thomson's original 'Composition No. 1' preparations often employed powdered seed. The seeds were listed separately in the United States Pharmacopoeia (USP) through various editions. Due to the higher alkaloid concentration, dosing must be adjusted downward compared to the whole herb -- seed preparations carry greater risk of emetic and toxic effects if dosed incautiously.
Whole plant
Preferred: Fresh whole plant tincture (historical/folk use only)
Some historical traditions, particularly the Thomsonian system, used the entire fresh plant including roots in some preparations, though this is uncommon in modern practice. The roots contain lower alkaloid levels than the aerial parts and seeds. Modern pharmacopeial practice restricts the drug to the aerial portions.
Key Constituents
Piperidine alkaloids (lobeline group)
The piperidine alkaloids, principally lobeline, are responsible for virtually all of the major pharmacological actions of Lobelia inflata: respiratory antispasmodic (bronchospasmolytic) activity via bronchial smooth muscle relaxation and reflex respiratory stimulation; emetic activity at moderate-to-high doses via stimulation of the chemoreceptor trigger zone and vagal afferents; nicotinic receptor modulation underlying the historical use as a smoking cessation aid; and nervine relaxant/antispasmodic activity at low doses. The dose-dependent biphasic pharmacology is critical: at small doses, lobeline stimulates respiration, relaxes bronchial smooth muscle, and produces a mild nervine relaxant effect; at moderate doses, it acts as an expectorant and diaphoretic; at larger doses, it produces nausea and emesis; and at toxic doses, it causes respiratory depression, cardiovascular collapse, and potentially death. This narrow therapeutic window defines the clinical character of lobelia and demands careful, experienced dosing. The alkaloid content varies significantly with plant part (seeds > herb), harvest timing, geographic origin, and post-harvest processing, making standardization or at minimum consistent sourcing essential for safe use.
Organic acids
The organic acids are minor contributors to the overall pharmacological profile of lobelia. Lobelic acid serves primarily as a quality marker and degradation indicator. Chelidonic acid may contribute modestly to anti-inflammatory effects but is not considered a primary therapeutic constituent.
Terpenoids and sterols
Beta-amyrin palmitate and related triterpenoids are minor constituents that may contribute to the anti-inflammatory and counterirritant effects of topical lobelia preparations (liniments, ointments). They are not considered primary therapeutic compounds.
Flavonoids
Flavonoids are minor, secondary constituents in lobelia. They may contribute modestly to antioxidant and anti-inflammatory properties but are not the basis for any of the primary therapeutic indications.
Other constituents
The fixed oil, gum, and resin are matrix constituents that influence the extraction, bioavailability, and physical properties of lobelia preparations. The seed oil particularly affects tincture preparation and extraction efficiency. These are not considered independently therapeutic but are relevant to formulation.
Herbal Actions
The defining therapeutic action of Lobelia inflata and the basis for its historical pre-eminence in respiratory medicine. Lobeline and related alkaloids relax bronchial smooth muscle through both direct myorelaxant mechanisms and reflex pathways. The bronchospasmolytic effect involves: (1) stimulation of the respiratory center via carotid body chemoreceptor activation at low doses, deepening and regularizing respiration; (2) direct relaxation of bronchial smooth muscle, relieving bronchospasm; (3) vagal afferent stimulation that reflexively modifies bronchomotor tone. Eclectic physicians considered lobelia the most reliable botanical bronchospasmolytic available, and it was the primary treatment for acute asthmatic paroxysm in Eclectic practice for over a century. The action is dose-dependent: small, frequent doses produce gradual bronchial relaxation without emesis; larger doses provoke coughing and expectoration before relaxation occurs. John King's American Dispensatory (1898) described the respiratory action as 'relaxing spasm of the bronchial muscles and promoting free respiration.' Harvey Wickes Felter, in the Eclectic Materia Medica (1922), considered lobelia 'the most certain relaxant of spasm in all of the materia medica, especially bronchial spasm.'
[1, 2, 3, 4]Lobelia is one of the most reliable botanical emetics, producing dose-dependent nausea and vomiting. At moderate to large doses, lobeline stimulates the chemoreceptor trigger zone (CTZ) in the area postrema and activates vagal afferents from the gastrointestinal tract, producing forceful emesis. This emetic action was the cornerstone of Samuel Thomson's therapeutic system (Thomsonian medicine), in which therapeutic vomiting was considered essential to 'clear obstructions' and restore the vital heat. Thomson's 'No. 1' remedy was lobelia, used deliberately to produce vigorous emesis. In the Thomsonian paradigm, the emetic action was not a side effect but the primary therapeutic goal -- the theory held that disease resulted from cold and obstruction, and emesis was the most direct means of restoring health. IMPORTANT HISTORICAL CONTEXT: Thomson's aggressive use of lobelia as an emetic led to his arrest and trial for murder in 1809 after a patient, Ezra Lovett, died following treatment that included lobelia administration. Thomson was acquitted after the prosecution's star botanical witness misidentified the plant in question, but the 'Lobelia Trials' became a defining moment in American medical history, crystallizing the conflict between 'regular' (orthodox) medicine and 'irregular' (botanical) practice. The trial galvanized popular support for medical freedom and the right of non-licensed practitioners to use herbal remedies. Modern herbalists rarely use lobelia as a deliberate emetic, as gentler alternatives exist and the emetic dose is uncomfortably close to the toxic dose.
[1, 2, 10]Promotes the discharge of mucus from the respiratory tract
At sub-emetic doses, lobeline promotes bronchial secretion and expectoration through reflex mechanisms involving vagal stimulation of bronchial glands and mild irritation of the respiratory mucosa. The expectorant action bridges the continuum between the bronchospasmolytic effect (at lower doses) and the emetic effect (at higher doses). In practice, the ideal expectorant dose produces a slight sensation of nausea with increased productive coughing and mucus clearance, without progressing to actual vomiting. Eclectic and Thomsonian practitioners used this action for bronchitis, croup, whooping cough, and respiratory congestion. The British Herbal Pharmacopoeia (1983) lists lobelia specifically as an expectorant for bronchitic asthma and bronchitis.
[1, 3, 4]At small doses, lobelia produces a systemic relaxant and antispasmodic effect on both smooth and skeletal muscle. This generalized antispasmodic action extends beyond the respiratory system to include gastrointestinal smooth muscle, skeletal muscle (used topically and internally for muscle spasm), and vascular smooth muscle. The nervine relaxant effect is central to the Eclectic concept of lobelia as an 'intelligent herb' or 'thinking herb' -- a term coined by Eclectic physicians who observed that lobelia seemed to direct its relaxant action to wherever tension or spasm existed in the body. Felter (1922) described lobelia as producing 'relaxation of tissues wherever there is undue excitability or spasmodic contraction.' This interpretation, while teleological, reflects the clinical observation that small-dose lobelia can relieve diverse spasmodic conditions. The mechanism involves nicotinic receptor modulation producing ganglionic effects that reduce sympathetic tone, as well as direct smooth muscle relaxation. Used by Eclectics for convulsions, colic, menstrual cramps, and musculoskeletal tension.
[1, 2, 3]The anti-asthmatic action of lobelia is a composite of its bronchospasmolytic, expectorant, and nervine relaxant properties applied specifically to asthmatic conditions. Lobelia was the foremost botanical treatment for asthma in 19th- and early 20th-century American herbal practice. Both the Eclectic and Thomsonian systems considered it indispensable for acute asthmatic paroxysm. Lobelia was included in proprietary asthma cigarettes and asthma powders (burned and inhaled) that were widely sold in American and British pharmacies well into the 20th century. The British Pharmaceutical Codex and multiple pharmacopeias listed lobelia for bronchial asthma. Lobeline was also used as a standalone pharmaceutical agent for asthma in the early-to-mid 20th century, though it was eventually superseded by synthetic beta-agonists and other bronchodilators.
[1, 3, 4, 7]Promotes perspiration
In the Thomsonian system, lobelia was considered a powerful promoter of perspiration, particularly when combined with capsicum (Capsicum annuum) in the 'composition powder' and steam bath protocols that formed the core of Thomsonian therapy. Thomson believed that promoting sweating was essential to restoring the body's natural heat. The diaphoretic action of lobelia alone is mild at sub-emetic doses but is potentiated by combination with warming herbs and external heat application. Modern herbalists do not typically rely on lobelia as a primary diaphoretic.
[2, 10]Applied topically as a liniment, poultice, or plaster, lobelia produces local counterirritant, rubefacient, and antispasmodic effects. The alkaloids penetrate the skin and produce local vasodilation, warmth, and relaxation of underlying musculature. Topical lobelia preparations were widely used by Eclectic and Thomsonian practitioners for muscle spasm, torticollis (wry neck), pleuritic pain, chest congestion, and musculoskeletal pain. The topical route avoids the emetic risk associated with internal use. Eclectic liniments commonly combined lobelia with capsicum, camphor, and other counterirritants. The 'Lobelia and Capsicum Liniment' was a standard Eclectic preparation.
[1, 2, 3]Lobelia stimulates salivary secretion, both reflexively (through its nauseant properties) and through direct cholinergic-like effects on salivary glands. This action is evident immediately upon chewing the fresh leaf or tasting the tincture -- copious salivation occurs rapidly. While not a primary therapeutic action, sialagogic activity is diagnostically useful (taste testing of fresh or dried herb) and contributes to the overall secretory-stimulating profile that includes bronchial secretion enhancement and gastric secretion stimulation.
[1, 2]Therapeutic Indications
Respiratory System
Bronchospasm and asthma (acute and chronic)
The primary historical indication for lobelia across all American herbal traditions. Eclectic, Thomsonian, Physiomedicalist, and Native American practitioners all used lobelia for asthmatic bronchospasm. Felter (1922) considered it 'the most direct relaxant of bronchial spasm in the entire materia medica.' Used for acute asthmatic paroxysm (often as tincture in small, frequent doses every 10-15 minutes until breathing eases), chronic asthma (in regular low-dose administration), and exercise-induced bronchospasm. Lobeline's bronchospasmolytic mechanism -- direct smooth muscle relaxation plus reflex respiratory stimulation -- has been validated in pharmacological studies, though modern clinical trials of crude lobelia preparations for asthma are essentially absent. Lobeline sulfate was briefly used as a pharmaceutical bronchodilator in the early-to-mid 20th century before being superseded by selective beta-2 agonists. The British Herbal Pharmacopoeia (1983) lists bronchitic asthma as a specific indication.
[1, 2, 3, 4]Bronchitis (acute and chronic)
Lobelia is used as an expectorant and antispasmodic in bronchitis, particularly where there is thick, tenacious mucus with bronchospasm, tight, non-productive cough, and a sense of chest constriction. The combined expectorant and bronchospasmolytic actions make lobelia specifically suited to bronchitis with spasmodic, unproductive coughing. At sub-emetic doses, it loosens bronchial secretions and relaxes bronchial smooth muscle, facilitating productive coughing and mucus clearance. The BHP lists bronchitis as a specific indication. Often combined with other respiratory herbs: Prunus serotina (wild cherry bark) for cough suppression, Tussilago farfara (coltsfoot) or Verbascum thapsus (mullein) for demulcent expectorant action, and Capsicum annuum to enhance circulatory diffusion.
[1, 3, 4]Whooping cough (pertussis)
Lobelia was extensively used by Eclectic and Thomsonian physicians for whooping cough (pertussis), considered one of the most important botanical remedies for this condition in the 19th century. The rationale was the antispasmodic/bronchospasmolytic action against the violent paroxysmal coughing characteristic of pertussis. Administered in very small doses (drop doses of tincture) to children. King's American Dispensatory recommended lobelia for 'spasmodic cough of every form, and especially whooping cough.' Must be used with extreme caution in children; this is a historical indication only and is not recommended for unsupervised use in children given modern treatment options.
[1, 2, 3]Croup and laryngospasm
Eclectic physicians used lobelia for croup (laryngotracheobronchitis) and laryngospasm, relying on the combined antispasmodic and emetic actions. At emetic doses, lobelia forcefully cleared mucus from the upper airways; at sub-emetic doses, it relaxed laryngeal and bronchial spasm. This was a common emergency application in Eclectic practice. Ellingwood (1919) described it as 'one of our most efficient remedies in the treatment of membranous croup.' Historical indication only; modern medical management of croup has superseded this use.
[2, 3]Nervous System
Anxiety and panic (acute, with respiratory tightness)
Lobelia was used by Eclectic physicians for acute anxiety and panic, particularly when accompanied by chest tightness, shallow breathing, and a sensation of constriction. The Eclectic concept of lobelia as an 'intelligent herb' encompassed its ability to identify and release the locus of spasm or tension, whether in the bronchi, the skeletal muscles, or the 'nervous system' broadly. Felter described lobelia for 'nervous unrest and excitability, with depression' and for patients who 'cannot get their breath' from anxiety. The mechanism likely involves nicotinic receptor modulation reducing sympathetic hyperactivation and the direct bronchospasmolytic action relieving the chest tightness component of panic. Drop doses (1-5 drops of tincture) are used for this indication. This is an Eclectic traditional use with no modern clinical trial evidence but is valued by contemporary herbalists who work with lobelia.
[1, 3]Convulsions and seizures (historical/Eclectic)
Eclectic physicians used lobelia for convulsions and epileptiform seizures, relying on the powerful general antispasmodic action. This was considered an emergency indication where lobelia's rapid onset of action was valued. Lobeline has demonstrated anticonvulsant properties in animal models. This is strictly a historical use; lobelia is not a substitute for modern anticonvulsant medications, and seizure management requires medical supervision.
[1, 2]Nicotine addiction and smoking cessation
Lobeline's structural similarity to nicotine and its partial agonist activity at nicotinic acetylcholine receptors (particularly alpha-4-beta-2 nAChRs) provided the pharmacological rationale for its use as a smoking cessation aid. Lobeline sulfate was marketed as a smoking deterrent in the mid-20th century (products such as Bantron, CigArrest, and Nicoban) and was included in the over-the-counter drug monograph by the US FDA. However, a Cochrane systematic review (Stead & Hughes 2012) evaluating the clinical evidence concluded that there was 'no evidence that lobeline has any significant effect on smoking cessation' and noted methodological limitations of available trials. The FDA subsequently removed lobeline-containing products from the OTC smoking cessation category in 1993, stating insufficient evidence of efficacy. Despite this, pharmacological research on lobeline as a dopamine and norepinephrine transporter modulator, as well as a VMAT2 inhibitor, continues to generate interest in lobeline analogs for addiction research. The crude herb is not recommended as a standalone smoking cessation treatment based on current evidence.
[7, 8]Musculoskeletal System
Muscle spasm and tension (topical and internal)
Lobelia's systemic and local antispasmodic actions make it useful for musculoskeletal spasm. Topically, lobelia liniment is applied to areas of muscle spasm, tension, and contracture, where the alkaloids penetrate the skin and produce local relaxation of skeletal muscle. Internally, small doses produce generalized muscle relaxation. Eclectic practitioners particularly valued lobelia for torticollis (wry neck/spasmodic stiff neck), back spasm, and muscle cramps. Felter recommended lobelia liniment for torticollis as a 'prompt and reliable' treatment. The topical route is preferred for musculoskeletal applications as it avoids systemic emetic effects while delivering alkaloids directly to the affected musculature.
[1, 2, 3]Torticollis (wry neck, spasmodic)
A specific and often-cited Eclectic indication. Lobelia liniment applied topically to the affected cervical muscles, often combined with gentle heat application, was considered one of the most effective botanical treatments for acute spasmodic torticollis. Ellingwood and Felter both highlighted this as a key indication. Often combined with Viburnum opulus (cramp bark) internally for systemic antispasmodic effect. This remains a valued application among herbalists who use lobelia.
[1, 3]Digestive System
Emesis (deliberate induction of vomiting -- historical/Thomsonian)
In the Thomsonian medical system (early 19th century), deliberate induction of vomiting with lobelia was the cornerstone therapeutic intervention. Samuel Thomson's system classified lobelia as the 'No. 1' remedy and prescribed it to induce 'courses of vomiting' (called 'courses' or 'pukes') as a means of expelling disease. Thomson's theory held that disease was caused by cold and internal obstruction, and that vigorous emesis, combined with steam baths and warming herbs (capsicum, bayberry), would restore the body's natural heat and vital force. A typical Thomsonian course involved drinking warm lobelia tea or tincture in increasing doses until vomiting occurred, often followed by additional doses to ensure thorough emesis. This practice was both Thomson's signature contribution and the source of his greatest controversy, including his murder trial. MODERN NOTE: Deliberate induction of emesis with lobelia is NOT recommended in modern herbal practice. It is traumatic, potentially dangerous (risk of aspiration, dehydration, and alkaloid toxicity), and effective alternatives exist for any indication that might theoretically justify therapeutic emesis.
[10]Spasmodic digestive conditions (colic, esophageal spasm)
At small sub-emetic doses, lobelia's antispasmodic action extends to gastrointestinal smooth muscle. Eclectic physicians used drop doses for esophageal spasm ('globus'), gastric spasm, and intestinal colic. The same dose-dependent principle applies: tiny doses relax, larger doses stimulate and then provoke vomiting. This requires precise dosing and is best managed by experienced practitioners.
[1, 2]Skin / Integumentary
Insect bites and stings (topical)
A traditional folk and Native American use. Fresh lobelia leaf poultice or lobelia tincture applied topically to insect bites and bee stings. Reported to reduce pain, swelling, and itching. The counterirritant and anti-inflammatory properties of the alkaloids may mediate this effect. This is a minor traditional use with no modern clinical validation but is considered low-risk when applied topically.
[1, 12]Contact dermatitis and poison ivy (topical)
Traditional folk use of lobelia poultice or wash for contact dermatitis, including poison ivy (Toxicodendron radicans) rash. The anti-inflammatory and counterirritant properties may provide symptomatic relief. Limited modern evidence.
[12]Energetics
Temperature
warm
Moisture
neutral
Taste
Tissue States
wind/tension, cold/depression, damp/stagnation
In the Western herbal energetics framework, lobelia is classified as a warm, diffusive, and strongly relaxant herb. The dominant taste is acrid/pungent -- an intensely burning, tobacco-like sensation on the tongue that produces immediate salivation and, at larger quantities, nausea. This acrid quality indicates lobelia's powerful ability to move and disperse stagnant conditions, particularly spasmodic tension. Matthew Wood describes lobelia as the 'supreme relaxant of the materia medica,' acting wherever there is tension, constriction, or spasm in the body. In Thomsonian energetics, lobelia was central to the system's heat-based model of disease: Thomson classified it as 'warming' because it promoted the body's natural heat (via diaphoresis and vasodilation) and cleared 'cold obstructions.' The Physiomedicalist tradition (inheriting from Thomson) classified lobelia as a 'diffusive stimulant relaxant' -- a unique category indicating that it initially stimulates vital force (diffusive stimulant), then produces systemic relaxation. This diffusive quality is key: lobelia's warmth is not a sustained heating like ginger or cayenne, but rather a rapid, spreading, dispersing warmth that moves outward and then gives way to relaxation. In terms of tissue states, lobelia most specifically addresses wind/tension patterns (spasm, constriction, hypertonic states) -- this is its premier indication. It also addresses cold/depression (stagnant, underactive conditions where circulation and secretion are sluggish) and damp/stagnation (congested respiratory passages, thick immobile mucus). CAVEAT: Herbal energetics are interpretive frameworks within Western herbalism and are not standardized across all practitioners.
Traditional Uses
Thomsonian medicine (Samuel Thomson's system, early 19th century)
- Classified as 'No. 1' remedy (the emetic herb) in Thomson's six-herb system -- the most important medicine in the entire Thomsonian materia medica
- Deliberate induction of therapeutic emesis ('courses') to expel disease and restore the body's natural heat
- Combined with capsicum (No. 2), bayberry (No. 3), bitters (No. 4), and other herbs in systematic 'courses of medicine'
- 'Lobelia in vinegar' (acetum lobeliae) -- a key Thomsonian preparation combining lobelia herb with apple cider vinegar, considered an essential medicine for every household
- Used in steam bath protocols: lobelia tea administered during or after steam bathing to promote vigorous sweating and emesis simultaneously
- Treatment of fevers, colds, respiratory complaints, and virtually all acute and chronic diseases through the emetic/diaphoretic protocol
- Topical application as a poultice for sprains, bruises, and inflammatory swellings
"Samuel Thomson (1769-1843) built his entire system of medicine around lobelia after reportedly learning of its use from an elderly woman herbalist (often identified as 'Widow Benton' or a Native American healer) as a young man in New Hampshire. Thomson later claimed to have discovered the plant himself in childhood, noting the intense burning and vomiting that occurred after chewing the plant. He went on to develop a complete medical system based on the theory that disease resulted from cold and obstruction, and that restoring the body's natural warmth through emetics (lobelia), stimulants (capsicum), and steam baths was the universal cure. Thomson patented his system in 1813 (US Patent, 'Thomson's Improved System of Botanic Practice of Medicine') and sold 'Family Right' certificates authorizing purchasers to practice his methods. At its peak, an estimated 3 million Americans (out of a total population of approximately 13 million) used Thomsonian medicine. Thomson's famous dictum: 'Heat is life, cold is death.' Lobelia was so central to his system that it became the focal point of the most dramatic legal conflict in American herbal history. In 1809, Thomson was arrested and charged with murder following the death of Ezra Lovett, who had been treated with lobelia and capsicum under Thomson's direction. The trial in 1809 in Salem, Massachusetts, was a sensation. Thomson was acquitted after the prosecution's expert witness, a Dr. French, misidentified the plant specimen presented as evidence, claiming it was Lobelia siphilitica rather than L. inflata. The acquittal was seen as a victory for medical liberty and populist healthcare. Thomson's system declined after his death in 1843 but directly influenced the development of Physiomedicalism and contributed ideas to Eclectic medicine."
[10]
Eclectic medicine (19th-20th century American medical tradition)
- Respiratory antispasmodic for bronchial asthma, bronchitis, whooping cough, and croup -- considered the most important botanical bronchospasmolytic
- Nervine relaxant for anxiety, panic, nervous excitability with depression, and 'hysterical' conditions
- Specific for torticollis (wry neck) applied as liniment topically and given internally
- General antispasmodic for convulsions, colic, muscle spasm, and esophageal spasm
- Combined with other herbs as a 'synergist' or 'diffusive' agent to potentiate the action of other medicines and improve their distribution through the body
- Emetic at larger doses (though the Eclectics generally preferred smaller, sub-emetic doses and moved away from the aggressive Thomsonian emetic protocol)
- Topical counterirritant liniment for pleurisy, chest congestion, and musculoskeletal pain
- As a catalyst in compound prescriptions, where a few drops of lobelia tincture were added to enhance the action of the primary herb
"The Eclectic medical movement (ca. 1830-1939) refined and moderated the Thomsonian approach to lobelia. Whereas Thomson used lobelia primarily as a heroic emetic, the Eclectics developed a sophisticated understanding of its dose-dependent pharmacology and emphasized small, sub-emetic doses for respiratory antispasmodic and nervine relaxant effects. John King, Harvey Wickes Felter, John Uri Lloyd, Finley Ellingwood, and other leading Eclectics wrote extensively on lobelia. Felter's Eclectic Materia Medica (1922) provides the most nuanced account: 'Lobelia in small doses is a diffusive stimulant and relaxant, controlling spasm wherever found. In moderate doses it is an expectorant and diaphoretic; in large doses it is an emetic. No remedy requires more accurate knowledge of the dose and its adaptation to the patient.' The Eclectics also introduced the concept of lobelia as an 'intelligent herb' (or 'thinking herb') -- the observation that lobelia seemed to 'find' the locus of spasm or tension in the body and direct its relaxant action there. While this concept has no pharmacological mechanism per se, it reflects clinical experience with lobelia's diffusive, systemic antispasmodic action at small doses. The Eclectics used lobelia tincture extensively, typically in doses of 5-30 drops (0.25-1.5 mL) rather than the large emetic doses favored by Thomson."
Native American medicine (multiple nations)
- Smoked as a substitute for tobacco (hence the common name 'Indian Tobacco') by several eastern nations, including the Penobscot, Crow, Cherokee, and Iroquois
- Used as a respiratory remedy for asthma, cough, and difficulty breathing by the Cherokee, Iroquois, and Penobscot
- Poultice applied to sore muscles, stiff neck, and inflammatory swellings
- Ceremonial emetic in purification rituals (some nations)
- Treatment for venereal diseases (Iroquois, Meskwaki)
- Insect bite and sting treatment (topical leaf poultice)
- Root tea used for stomach complaints and cramps
- Used as an antidote for other plant poisonings (some nations)
"Lobelia inflata was used by numerous Native American nations across eastern North America long before European contact. Daniel Moerman's comprehensive ethnobotanical database documents uses by the Penobscot, Cherokee, Iroquois (Haudenosaunee), Crow, Meskwaki (Fox), Chippewa (Ojibwe), Delaware (Lenape), and other nations. The plant was smoked, either alone or mixed with other herbs, and was used medicinally for respiratory complaints, pain, and as an emetic in purification ceremonies. Samuel Thomson claimed to have learned of lobelia from an 'old woman' herbalist, who may have been transmitting Native American knowledge. The depth of pre-contact Indigenous use of Lobelia inflata underscores that Thomson's 'discovery' of the plant was in fact an adoption of existing Indigenous medical knowledge, a historical pattern repeated across American botanical medicine. Traditional ecological knowledge of lobelia's habitat, harvest timing, and dose-dependent pharmacology was likely transmitted to early European settlers and subsequently to the Thomsonian and Eclectic traditions."
[12]
Physiomedicalism (American herbal tradition, mid-19th to early 20th century)
- Classified as a 'diffusive stimulant relaxant' -- a unique pharmacological category in the Physiomedicalist system
- Used to restore vital force and nervous energy when depleted by disease
- Respiratory antispasmodic for asthma and bronchospasm
- Systemic relaxant for muscular and nervous tension
- Combined with capsicum and other agents in modified Thomsonian protocols (the Physiomedicalists inherited Thomson's system but refined it considerably)
- Considered essential to the Physiomedicalist therapeutic armamentarium; W.H. Cook's Physio-Medical Dispensatory (1869) devoted extensive coverage to lobelia
"Physiomedicalism (ca. 1838-1920s) was a direct intellectual descendant of Thomsonian medicine, founded by Alva Curtis, who studied under Thomson but sought to place the system on a more rational and scientific footing. The Physiomedicalists retained lobelia as a cornerstone of their materia medica but developed more refined pharmacological concepts than Thomson's simple heat/cold model. The key innovation was the concept of the 'diffusive stimulant' -- a category of remedy that acts first by stimulating vital force and then by dispersing that stimulated energy throughout the body. Lobelia was the archetype of this category. W.H. Cook (Physio-Medical Dispensatory, 1869) described lobelia as 'a positive relaxant of the highest order' and emphasized that its action was to 'diffuse nervous energy' to areas of depletion while relaxing areas of excessive tension. This concept is remarkably similar to modern adaptogenic and nervine categories in contemporary herbalism."
British herbal medicine (19th-20th century)
- Introduced to British practice in the 1820s-1830s following the spread of Thomsonian ideas across the Atlantic
- Listed in the British Pharmaceutical Codex as an antispasmodic expectorant for asthma and bronchitis
- Included in the British Herbal Pharmacopoeia (1983) with specific indications: bronchitic asthma, bronchitis, and as an expectorant
- Briefly cultivated in England for medicinal purposes (early-to-mid 19th century)
- Component of proprietary asthma preparations (asthma cigarettes, smoking mixtures) widely sold in British pharmacies through the mid-20th century
- Subject of regulatory attention due to toxicity concerns; eventual restriction under the Medicines Act (1968) and subsequent herbal practitioner regulations
"Lobelia was introduced to British herbal practice through the influence of the Thomsonian movement, which spread to the United Kingdom in the 1830s through emigrant practitioners and published texts. Albert Isaiah Coffin, a self-taught American botanic practitioner, established Thomsonian (later 'Coffinite') practice in England and made lobelia a central feature of British botanic medicine. Lobelia was subsequently adopted into British pharmacy and listed in the British Pharmaceutical Codex and British Herbal Pharmacopoeia. Asthma cigarettes containing lobelia were widely available in British chemists' shops well into the 20th century. The British herbal tradition eventually adopted the Eclectic (rather than purely Thomsonian) approach to lobelia, favoring small doses as a respiratory antispasmodic rather than large emetic doses."
[4]
Modern Research
Lobeline as a nicotinic acetylcholine receptor ligand and smoking cessation agent
Cochrane systematic review evaluating the clinical evidence for lobeline as a smoking cessation aid. Lobeline's pharmacological profile as a partial agonist/competitive antagonist at nicotinic acetylcholine receptors (particularly alpha-4-beta-2 nAChRs) provided the rationale for its investigation. Multiple OTC products containing lobeline sulfate were marketed for smoking cessation in the mid-to-late 20th century.
Findings: The review identified a small number of controlled trials of lobeline for smoking cessation but found them to be methodologically flawed, with small sample sizes, short follow-up periods, and inconsistent outcome measures. The review concluded: 'There is no evidence that lobeline has an effect on smoking cessation.' The quality of evidence was rated as insufficient to support or refute efficacy. The US FDA removed lobeline-containing products from the approved OTC smoking cessation monograph in 1993 due to insufficient evidence of efficacy.
Limitations: Limited number of trials available for review. Most trials were conducted before modern standards for clinical trial methodology (randomization, blinding, biochemical verification of abstinence). Short follow-up periods (most under 6 months). Heterogeneous lobeline preparations and dosing. The Cochrane review focused on isolated lobeline sulfate, not crude lobelia preparations, which contain multiple alkaloids.
[7]
Lobeline pharmacology: monoamine transporter and vesicular transporter interactions
Comprehensive review of lobeline's interactions with dopaminergic and noradrenergic neurotransmission, with emphasis on its potential as a pharmacological tool for substance abuse research. Lobeline inhibits dopamine uptake via the dopamine transporter (DAT) and, more potently, inhibits vesicular monoamine transporter 2 (VMAT2)-mediated dopamine storage.
Findings: Lobeline inhibits dopamine uptake at the dopamine transporter (DAT, IC50 approximately 80 microM) and, more potently, inhibits VMAT2-mediated vesicular dopamine uptake (IC50 approximately 1-2 microM). This dual action results in redistribution of dopamine from vesicular stores to the cytoplasm, followed by reverse transport through DAT, producing dopamine release that mimics some aspects of psychostimulant action. Lobeline also inhibits norepinephrine transporter (NET) function. These monoamine transporter interactions are distinct from lobeline's nicotinic receptor activity and provide a mechanistic basis for its investigation in methamphetamine, nicotine, and other substance use disorders. Lobeline analogs (e.g., lobelane, MTD) with improved selectivity for VMAT2 over nAChRs have been developed as research tools.
Limitations: Most findings are from in vitro and animal models. Clinical translation has been limited. Lobeline itself has a narrow therapeutic index and poor pharmacokinetic properties (rapid metabolism, short half-life) that limit its utility as a drug candidate. Research has shifted toward lobeline analogs with improved properties.
[8]
Lobeline and methamphetamine: preclinical evidence for VMAT2-mediated interactions
Investigation of lobeline's ability to attenuate the behavioral and neurochemical effects of methamphetamine through VMAT2 inhibition, using rodent models of drug self-administration and behavioral sensitization.
Findings: In animal models, lobeline reduced methamphetamine self-administration, attenuated methamphetamine-evoked dopamine release in the nucleus accumbens, and blocked methamphetamine-induced behavioral sensitization. The proposed mechanism is that lobeline, by inhibiting VMAT2, prevents methamphetamine from releasing dopamine from vesicular stores -- effectively competing with methamphetamine at the vesicular transporter level. These findings generated significant research interest in lobeline and its analogs as potential anti-methamphetamine agents.
Limitations: All preclinical data; no human clinical trials of lobeline for methamphetamine use disorder. Lobeline's own toxicity profile (narrow therapeutic index, emetic effects) limits its direct clinical application. Research has shifted to lobeline analogs with better therapeutic indices.
Historical and regulatory review of lobelia safety and toxicology
Review of the safety profile, toxicology, and regulatory history of Lobelia inflata and lobeline, including historical case reports and regulatory actions.
Findings: Lobelia has a well-documented history of toxicity at high doses, consistent with the pharmacology of its principal alkaloid lobeline. Toxic effects are dose-dependent and include: nausea, profuse vomiting, diarrhea, abdominal pain, excessive salivation, profuse sweating, tremor, tachycardia followed by bradycardia, hypotension, respiratory stimulation followed by respiratory depression, convulsions (rare), coma, and potentially death from respiratory paralysis. Fatal cases have been reported historically but are rare and generally associated with massive overdose or deliberate poisoning. The estimated lethal dose of lobeline in humans is approximately 4 grams (though this is uncertain and individual susceptibility varies). The emetic action of lobelia is, paradoxically, protective: overdose typically produces such vigorous vomiting that toxic quantities are expelled before systemic absorption reaches fatal levels. The AHPA (American Herbal Products Association) has classified lobelia as class 2b (not to be used during pregnancy) and 2c (not to be used during lactation). The German Commission E did not approve lobelia due to efficacy concerns. The US FDA removed lobeline from the OTC smoking cessation monograph in 1993. In the UK, lobelia is a restricted herb that may only be supplied by qualified herbal practitioners under the traditional herbal registration (THR) scheme.
Limitations: Historical case reports are often poorly documented and confounded by co-administered substances. The exact lethal dose in humans is uncertain. Modern poison control data on lobelia overdose is limited, as serious poisonings are rare.
[5]
Bronchospasmolytic mechanism of lobeline
Pharmacological investigation of the mechanisms by which lobeline relaxes bronchial smooth muscle, including in vitro tissue bath studies and receptor binding assays.
Findings: Lobeline relaxes pre-contracted bronchial smooth muscle in isolated tissue preparations through mechanisms that include: (1) stimulation of nicotinic receptors on airway sensory nerve endings, producing reflex bronchodilation; (2) inhibition of voltage-gated calcium channels in bronchial smooth muscle cells, reducing intracellular calcium and muscle tone; (3) possible modulation of parasympathetic (cholinergic) bronchoconstriction via ganglionic nicotinic receptor effects. The bronchospasmolytic action is rapid in onset and dose-dependent. Lobelanidine may contribute more strongly to the direct smooth muscle relaxant component than lobeline itself. The reflex respiratory stimulant action (via carotid body chemoreceptor stimulation) is mediated by nicotinic receptor activation and results in deeper, more regular respiration at low doses.
Limitations: Most data from isolated tissue and animal models. Direct clinical measurement of lobeline's bronchospasmolytic effect in asthmatic patients using modern pulmonary function testing has not been performed. The pharmacology described is consistent with traditional clinical observations but lacks confirmatory human clinical trials.
Lobeline in attention deficit and cognitive function
Preliminary investigation of lobeline's potential for improving attention and cognitive function based on its nicotinic receptor agonist and monoamine modulating properties.
Findings: Nicotinic acetylcholine receptor agonists and partial agonists have demonstrated cognitive-enhancing effects in preclinical models, and lobeline's activity at alpha-4-beta-2 nAChRs placed it within this pharmacological class. Animal studies showed that lobeline improved performance in attention and memory tasks at sub-toxic doses. The VMAT2 inhibition and consequent dopamine redistribution may also contribute to attention-enhancing effects, as dopaminergic signaling in the prefrontal cortex is critical for sustained attention.
Limitations: Entirely preclinical. No human clinical trials of lobeline for ADHD or cognitive enhancement. The narrow therapeutic window and emetic side effects of lobeline make it a poor drug candidate for chronic cognitive indication. Research has pivoted to synthetic lobeline analogs with improved safety profiles.
[8]
The Lobelia Trials and American medical freedom: historical analysis
Historical analysis of Samuel Thomson's arrest, trial, and acquittal on charges of murder related to lobelia administration, and the broader impact on American medical pluralism, licensing, and herbal medicine regulation.
Findings: In 1809, Samuel Thomson was arrested in Beverly, Massachusetts, charged with killing Ezra Lovett by administering lobelia. The trial, held before the Massachusetts Supreme Court, became a landmark case in American medical history. The prosecution argued that lobelia was a deadly poison and that Thomson, as an unlicensed practitioner, had committed murder by administering it. Thomson's defense rested on the safety and efficacy of lobelia when properly used, and on the right of individuals to choose their medical treatment. The prosecution's case was undermined when its botanical expert, Dr. French, failed to correctly identify the lobelia specimen, confusing L. inflata with L. siphilitica. Thomson was acquitted. The trial had profound consequences: (1) it galvanized the 'medical freedom' movement, fueling public opposition to medical licensing laws that were seen as protecting the monopoly of 'regular' physicians; (2) several states subsequently repealed their medical licensing laws in the 1830s-1840s, partly in response to Thomsonian political organizing; (3) the trial established that herbal medicine use was a matter of personal liberty, not criminal conduct; (4) it made lobelia and Thomson household names, dramatically expanding the popularity of Thomsonian medicine. The Lobelia Trials represent a defining moment in the relationship between orthodox medicine, alternative medicine, and the state in America.
Limitations: Historical analysis based on primary sources of variable reliability. Thomson's own account (New Guide to Health, 1822) is self-serving. Court records are incomplete. The broader historiographic significance is well established by academic historians of medicine.
[10]
Preparations & Dosage
Tincture
Strength: 1:5, 60% ethanol (dried herb). 1:5, 60% ethanol (dried seed -- more potent, reduce dose by 2/3 to 3/4). Some practitioners use 1:10 preparations for safer drop dosing.
Prepare from dried aerial herb or seed using standard maceration. The most common preparation in modern herbal practice. Use dried flowering/fruiting herb, finely chopped, macerated in 60% ethanol at a 1:5 ratio for 2-4 weeks with daily agitation. Press and filter through muslin and coffee filter. SEED TINCTURE: Use dried crushed seed at 1:5 in 60% ethanol; the seed tincture is significantly more potent per drop than herb tincture and must be dosed accordingly. The tincture should have a characteristic acrid, burning taste that produces immediate salivation when a drop is placed on the tongue -- this is a key quality indicator. A tincture that does not produce this acrid sensation is likely degraded or of poor quality.
SMALL (antispasmodic/relaxant) DOSE: 0.25-1 mL (5-20 drops) of herb tincture, 3-4 times daily or as needed. DROP DOSING: For acute bronchospasm or panic, 3-10 drops every 10-15 minutes until relief occurs or mild nausea signals the dose limit. MODERATE (expectorant) DOSE: 1-2 mL, 3 times daily. EMETIC DOSE (historical, NOT recommended): 4-8 mL. SEED TINCTURE: Use approximately one-third to one-quarter the dose of herb tincture. CRITICAL: Begin at the lowest dose and increase cautiously. The onset of nausea is the signal to stop increasing the dose.
As needed for acute conditions (every 10-30 minutes in drop doses for bronchospasm). For chronic conditions: 3-4 times daily.
Short-term use (days to a few weeks) for acute respiratory conditions. Not typically used as a long-term tonic herb. Chronic use requires practitioner supervision.
NOT recommended for children under 12 without expert practitioner supervision. For children 6-12 years: 1-5 drops of herb tincture diluted in water, under close supervision, as a respiratory antispasmodic only. The risk of emesis and toxicity is greater in children due to lower body weight.
The tincture is the most practical and dose-controllable modern preparation. Drop dosing allows precise titration to the individual patient's response -- this is essential with lobelia because the therapeutic window between effective antispasmodic doses and emetic doses is narrow and individually variable. The Eclectic approach of starting with a few drops and gradually increasing to effect is the safest method. The BHP (1983) specifies a tincture dose of 0.2-0.6 mL (herb) three times daily. Lobelia tincture is often combined with other herbs rather than used alone: classic combinations include lobelia + wild cherry bark (Prunus serotina) for cough; lobelia + capsicum for enhanced diffusion and warmth; lobelia + cramp bark (Viburnum opulus) for musculoskeletal spasm; and small amounts of lobelia added to cough/respiratory formulas as an antispasmodic catalyst.
vinegar-extract
Strength: Approximately 1:3 to 1:4 (dried herb to vinegar) by traditional Thomsonian method. Not formally standardized.
THOMSONIAN PREPARATION (Acetum Lobeliae): Fill a glass jar one-quarter to one-third full with dried lobelia herb (preferably including seed). Cover completely with raw, unfiltered apple cider vinegar. Cap tightly and macerate for 2-4 weeks, shaking daily. Strain through cheesecloth and store in a dark glass bottle. Samuel Thomson considered this preparation essential to his system and recommended that every family keep a supply on hand. The acetic acid solvent extracts the alkaloids effectively (lobeline is soluble in dilute acids) and the vinegar medium is more palatable to some patients than an alcohol-based tincture.
1-2 teaspoons (5-10 mL) in warm water, repeated every 15-30 minutes for acute respiratory distress. For maintenance: 1 teaspoon in water 2-3 times daily. The same dose-dependent caution applies as with tincture: begin with a small amount and increase carefully.
As needed for acute use; 2-3 times daily for sub-acute conditions.
Short-term. The vinegar preparation stores well (6-12 months if kept cool and dark) due to the preservative properties of vinegar.
Not recommended for children without expert supervision. If used for children over 6: 1/4 to 1/2 teaspoon diluted in warm water, under close supervision.
This is one of the oldest and most historically important lobelia preparations, directly associated with the Thomsonian medical system. Thomson considered 'lobelia in vinegar' a household essential and included instructions for its preparation in his 'New Guide to Health' (1822). The vinegar extraction is effective because the piperidine alkaloids are weak bases that form soluble salts in the acidic vinegar medium. The preparation has a sharp, acrid taste that is somewhat mitigated by the sourness of the vinegar. In Thomsonian practice, this preparation was used for everything from acute asthma to inducing therapeutic vomiting. Modern practitioners who use this preparation favor it for patients who cannot tolerate alcohol-based tinctures, including those in recovery from alcohol use disorders.
Capsule / Powder
Strength: 50-200 mg dried herb powder per capsule. Crude herb, not concentrated extract.
Dried lobelia herb, finely powdered (80-100 mesh), filled into size 0 or 00 vegetarian capsules. Dosing is less precise than with tincture and the therapeutic window is narrower when the herb is administered as a dry powder, because the dose cannot be titrated incrementally. For this reason, capsules are generally considered less suitable than tincture for conditions requiring precise dosing (acute bronchospasm, panic). However, capsules are used for lower-dose chronic administration and for patients who find the acrid taste of the tincture intolerable.
50-200 mg dried herb powder per capsule. Start with 50-100 mg (one capsule) and assess tolerance before increasing. Maximum single dose: 200 mg. Maximum daily dose: 600 mg in divided doses. The AHPA and safety literature advise caution: begin at the lowest dose.
1-3 times daily with water, taken after meals to reduce gastric irritation.
Short-term use only. Not for continuous long-term administration without practitioner oversight.
Not recommended in capsule form for children.
Capsules lose the important advantage of tincture dosing: the ability to taste the acrid sensation and titrate dose incrementally. The burning, sialagogue taste of lobelia tincture on the tongue is itself a physiological signal and safety check -- if the herb does not produce the characteristic burning sensation, it may be degraded; if the sensation is overwhelming, the dose may be too high. Capsules bypass this feedback mechanism. For this reason, many experienced lobelia practitioners prefer tincture or vinegar extract over capsules. Commercial lobelia capsules are available but should be from reputable manufacturers who verify alkaloid content. The BHP dose for dried herb (as opposed to tincture) is 0.2-0.6 g.
topical-liniment
Strength: Variable depending on preparation. Simple liniment: lobelia tincture (1:5) diluted with carrier oil. Compound liniment: lobelia tincture + capsicum tincture + carrier oil.
LOBELIA LINIMENT (Eclectic formula): Combine 1 part lobelia tincture (1:5 in 60% ethanol) with 1 part capsicum tincture (Capsicum annuum) and 2 parts a carrier oil (olive oil or sesame oil). Shake well before each use. Alternatively, prepare an infused oil: macerate dried lobelia herb in olive oil at a ratio of 1:5 for 4-6 weeks, strain, and combine with capsicum oleoresin or capsicum tincture. SIMPLE LOBELIA LINIMENT: Lobelia tincture applied directly or mixed with an equal part of olive oil. POULTICE: Fresh or dried lobelia herb moistened with warm water or vinegar, applied directly to the skin, covered with cloth, and left in place for 20-60 minutes.
Apply liniment to affected area 2-4 times daily, massaging into the skin. Cover with a warm cloth if desired. For poultice: apply for 20-60 minutes, 2-3 times daily.
2-4 times daily as needed for pain and spasm.
As needed for acute musculoskeletal conditions. Discontinue if skin irritation occurs.
Topical use is generally safer than internal use. Use a diluted liniment (1 part lobelia tincture to 4 parts carrier oil) for children over 6.
Topical lobelia preparations are a mainstay of Eclectic and Thomsonian practice for musculoskeletal conditions, avoiding the emetic risk of internal administration. The alkaloids penetrate the skin and produce local muscle relaxation, counterirritant vasodilation, and pain relief. The combination with capsicum enhances absorption (capsicum increases local blood flow and skin permeability) and adds warming, analgesic effects. Eclectic texts describe lobelia liniment as particularly effective for torticollis (wry neck), pleuritic chest pain, intercostal muscle spasm, and back spasm. Lobelia poultice was also applied to the chest for pneumonia and bronchitis (Eclectic practice). Topical use is considered significantly safer than internal use and can be employed where internal dosing is contraindicated or impractical.
Infusion (Tea)
Strength: 0.2-0.5 g dried herb per 250 mL water
Pour 250 mL (one cup) of hot water over 0.2-0.5 g (approximately 1/4 teaspoon or less) of dried lobelia herb. Steep covered for 10-15 minutes. Strain. Sip small amounts, assessing tolerance before drinking more. Do NOT prepare a strong infusion; lobelia infusion that is strong enough to have significant therapeutic effect is also strong enough to cause nausea and vomiting.
0.2-0.5 g dried herb per cup. Sip 1/4 cup at a time, up to 1-2 cups per day. Cease intake at the first sign of nausea.
1-2 times daily, as tolerated.
Short-term use only.
Not recommended.
Infusion (tea) is the least preferred modern preparation for lobelia because dose control is difficult and the strongly acrid taste is unpleasant. However, hot lobelia tea was the original Thomsonian preparation: Thomson's protocol for therapeutic emesis involved drinking successive cups of warm lobelia tea until vomiting occurred. In modern practice, infusion is rarely used as the primary preparation; tincture offers far superior dose control. If used, the infusion should be weak and sipped cautiously. The BHP lists infusion as a valid preparation form.
Safety & Interactions
Class 2c
Not to be used with specific medications (AHPA Botanical Safety Handbook)
Contraindications
Lobelia is contraindicated in pregnancy (AHPA class 2b). Lobeline crosses the placenta and may affect fetal respiration and cardiovascular function. The emetic action poses risks of dehydration, electrolyte disturbance, and uterine stimulation. No safety data in pregnancy. The Botanical Safety Handbook (AHPA, 2nd edition) and all major herbal safety references list pregnancy as an absolute contraindication for internal use. Topical use over small areas may be acceptable under practitioner guidance, but internal use must be avoided.
Lobelia is contraindicated during breastfeeding (AHPA class 2c). Lobeline and related alkaloids may be excreted in breast milk and could affect the nursing infant. No safety data in lactation. Avoid internal use while nursing.
Internal use is contraindicated in children under 6 years due to increased sensitivity to alkaloid effects, greater risk of toxicity at lower doses (lower body weight), and risk of aspiration if emesis occurs. Children 6-12 may receive drop doses under the direct supervision of a qualified herbal practitioner only.
Lobeline has cardiovascular effects including initial tachycardia followed by bradycardia, and hypotension at higher doses. Patients with severe cardiac disease, cardiac arrhythmias, or hemodynamic instability should avoid lobelia due to the risk of cardiovascular perturbation. Those with mild-to-moderate cardiovascular conditions should use lobelia only under practitioner supervision with small doses.
At toxic doses, lobeline can provoke convulsions. While lobeline has shown anticonvulsant effects at lower doses in animal models, the biphasic dose-response curve means that higher doses could potentially lower the seizure threshold. Patients with known seizure disorders should use lobelia with caution and only under practitioner supervision.
The emetic and gastric-irritant properties of lobelia could aggravate pre-existing gastrointestinal ulceration, gastritis, or active inflammatory bowel disease. Use with caution or avoid in patients with active upper GI pathology.
Drug Interactions
| Drug / Class | Severity | Mechanism |
|---|---|---|
| Nicotine (cigarettes, patches, gum, lozenges, e-cigarettes) (Nicotinic receptor agonists) | moderate | Lobeline is a partial agonist and competitive antagonist at nicotinic acetylcholine receptors (alpha-4-beta-2 subtype), the same receptor population targeted by nicotine. Concurrent use could result in either potentiation (at low lobeline doses where agonist activity predominates) or antagonism (at higher doses where competitive antagonism predominates) of nicotinic effects. The net result is unpredictable and depends on the relative doses and receptor occupancy. |
| Anticholinergic medications (atropine, scopolamine, antihistamines with anticholinergic effects, tricyclic antidepressants) (Anticholinergics/antimuscarinics) | theoretical | Lobeline's cholinergic-like effects (nicotinic receptor activation producing salivation, bronchial secretion, gastrointestinal stimulation) may be antagonized by anticholinergic medications. Conversely, lobelia may partially counteract the therapeutic anticholinergic effects of these drugs. The net clinical effect is difficult to predict. |
| Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) (Cholinesterase inhibitors) | theoretical | Cholinesterase inhibitors increase cholinergic neurotransmission. Lobeline's nicotinic receptor effects could theoretically produce additive cholinergic stimulation, potentially increasing the risk of gastrointestinal side effects (nausea, vomiting, diarrhea), bradycardia, and bronchospasm. |
| Sedatives and CNS depressants (benzodiazepines, opioids, barbiturates) (CNS depressants) | theoretical | At higher doses, lobeline has CNS and respiratory depressant effects. Concurrent use with other CNS depressants could theoretically produce additive central and respiratory depression. |
| Monoamine oxidase inhibitors (MAOIs: phenelzine, tranylcypromine, selegiline) (Antidepressants (MAOI class)) | theoretical | Lobeline modulates monoamine (dopamine, norepinephrine) release and reuptake. MAOIs inhibit the metabolism of monoamines. The combination could theoretically result in excessive monoaminergic stimulation, though this interaction is speculative and not documented clinically. |
Pregnancy & Lactation
Pregnancy
unsafe
Lactation
unsafe
Lobelia inflata is classified as AHPA class 2b (contraindicated in pregnancy) and 2c (contraindicated during lactation). No safety data exists for use during pregnancy or breastfeeding. The piperidine alkaloids, particularly lobeline, cross the placenta and may be excreted in breast milk. Lobeline affects nicotinic receptors, which play critical roles in fetal neurodevelopment. The emetic action of lobelia carries risks of dehydration, electrolyte disturbance, and aspiration during pregnancy. There is no circumstance in which internal use of lobelia during pregnancy or lactation can be justified given the availability of safer alternatives. Topical use (liniment) over small areas may carry less risk but should still be avoided as a precaution during pregnancy.
Adverse Effects
References
Monograph Sources
- [1] Felter HW. The Eclectic Materia Medica, Pharmacology and Therapeutics. John K. Scudder, Cincinnati, Ohio (1922)
- [2] King J, Lloyd JU. King's American Dispensatory, 18th edition. Ohio Valley Company, Cincinnati (1898)
- [3] Ellingwood F. American Materia Medica, Therapeutics and Pharmacognosy. Ellingwood's Therapeutist, Chicago (1919)
- [4] British Herbal Medicine Association. British Herbal Pharmacopoeia (BHP): Lobelia. British Herbal Medicine Association, Bournemouth, UK (1983)
- [5] Gardner Z, McGuffin M (eds). American Herbal Products Association's Botanical Safety Handbook, 2nd edition. CRC Press, Boca Raton (2013)
- [6] Cook WH. The Physio-Medical Dispensatory: A Treatise on Therapeutics, Materia Medica, and Pharmacy. Wm. H. Cook, Cincinnati (1869)
Clinical Studies
- [7] Stead LF, Hughes JR. Lobeline for smoking cessation. Cochrane Database Syst Rev (2012) ; 2 : CD000124 . DOI: 10.1002/14651858.CD000124.pub2 . PMID: 22336780
- [8] Dwoskin LP, Crooks PA. A novel mechanism of action and potential use for lobeline as a treatment for psychostimulant abuse. Biochem Pharmacol (2002) ; 63 : 89-98 . DOI: 10.1016/S0006-2952(01)00899-1 . PMID: 11841781
- [9] Harrod SB, Dwoskin LP, Crooks PA, Klebaur JE, Bardo MT. Lobeline attenuates d-methamphetamine self-administration in rats. J Pharmacol Exp Ther (2001) ; 298 : 172-179 . PMID: 11408539
Traditional Texts
- [10] Thomson S. New Guide to Health; or, Botanic Family Physician: Containing a Complete System of Practice, Upon a Plan Entirely New. E.G. House, Boston (1822)
- [11] Lloyd JU. History of the Vegetable Drugs of the Pharmacopoeia of the United States. Bulletin of the Lloyd Library of Botany, Pharmacy and Materia Medica, No. 18, Cincinnati (1911)
- [12] Moerman DE. Native American Ethnobotany. Timber Press, Portland, Oregon (1998)
Pharmacopeias & Reviews
- [13] British Herbal Medicine Association. British Herbal Pharmacopoeia 1983: Lobelia (Lobeliae Herba). British Herbal Medicine Association, Bournemouth (1983)
Last updated: 2026-03-02 | Status: review
Unlock the Full Materia Medica
This monograph is part of our complete evidence-based herbal reference. Enter your email to get free, unlimited access to all of our monographs.
No spam, ever. Unsubscribe anytime.
You're In!
You now have full access to all of our herbal monographs.