Herbal Monograph
Yerba santa
Eriodictyon californicum (Hook. & Arn.) Torr.
Namaceae (formerly placed in Hydrophyllaceae; sometimes listed under Boraginaceae sensu lato)
California's holy herb — premier respiratory expectorant with potent neuroprotective flavanones
Overview
Plant Description
Evergreen aromatic shrub, 1–2.5 m tall, branching from the base and often forming dense thickets through root suckering. Stems erect to ascending, woody at the base, green to brown, covered with a glossy, sticky, resinous exudate. Leaves alternate, lance-shaped to oblanceolate, 5–15 cm long, 1–3 cm wide, thick and leathery, with a glutinous (sticky) upper surface coated in a shiny resinous varnish, and a densely white-tomentose (woolly) lower surface between the veins; margins dentate to serrate; leaves often have a distinctive dark green, glossy, lacquered appearance from the surface resin. Flowers tubular-funnelform, lavender to white, 1–1.5 cm long, arranged in terminal helicoid cymes (scorpioid coils). Blooms April–July. Fruit a small, hard capsule containing 2–8 tiny seeds. The entire plant is strongly aromatic with a warm, balsamic, slightly sweet scent when crushed. Leaf surfaces and stems exude a dark, sticky resin, especially in warm weather, making the plant noticeably tacky to the touch.
Habitat
Dry, sun-exposed slopes in chaparral, open woodland, road cuts, burned areas, and rocky hillsides. A quintessential fire-adapted species — yerba santa is a vigorous post-fire colonizer that regenerates rapidly from root sprouts after wildfire and often dominates early post-fire plant communities. Prefers well-drained, rocky, sandy, or gravelly soils. Drought-tolerant once established. Typically found at elevations of 150–1,700 m.
Distribution
Native to California (widespread from northern to southern California, primarily west of the Sierra Nevada crest) and adjacent southern Oregon. E. californicum is the most widely distributed and commonly traded species of the genus. The broader genus Eriodictyon is restricted to western North America (California, Oregon, Nevada, Utah, Arizona, Baja California).
Parts Used
Leaf (Folium Eriodictyi)
Preferred: Tincture (fresh leaf preferred), syrup, or infusion; also smoked in some traditions
The leaf is the primary medicinal part, rich in flavanones (eriodictyol, homoeriodictyol), resinous compounds, and volatile oils. The thick resinous coating on the leaf surface contains much of the active chemistry. Both fresh and dried leaves are used. The US Pharmacopoeia included Eriodictyon leaf (as 'Eriodictyon' and 'Yerba Santa') from 1894–1947, and it remained in the National Formulary until 1960, primarily as a flavoring agent and expectorant. The Eclectics and California folk herbalists used the leaf as their primary preparation.
Key Constituents
Flavanones and flavonoids
The flavanone/flavonoid fraction is the most thoroughly characterized active constituent group in yerba santa. Eriodictyol and homoeriodictyol provide potent antioxidant, anti-inflammatory, and bitter-masking activity. The anti-inflammatory effects operate through multiple pathways (COX-2, 5-LOX, NF-κB), supporting the respiratory anti-inflammatory indication. Hispidulin's GABAergic activity adds a mild sedative/relaxant dimension. The bitter-masking property is pharmacologically unique — the National Formulary historically included yerba santa extract as a flavor corrective for bitter medications (particularly quinine).
Resins and balsamic compounds
The resinous fraction contributes to yerba santa's expectorant and respiratory-soothing properties. The balsamic resin is believed to stimulate bronchial mucus secretion (stimulant expectorant) while simultaneously providing a soothing, protective quality to irritated respiratory mucosa. This combination of stimulant and soothing properties makes yerba santa suitable for both dry, irritable coughs and productive coughs with thick, tenacious mucus.
Volatile (essential) oil
The volatile oil makes a modest contribution to the overall aromatic and warming quality of yerba santa. It is not the primary active fraction — unlike many aromatic herbs where the essential oil is the dominant active constituent, yerba santa's therapeutic activity is driven primarily by the flavanone and resin fractions.
Tannins
Tannins provide a secondary astringent action that complements the expectorant and anti-inflammatory effects. The mild astringency tones boggy, over-secreting respiratory tissue while the resinous fraction simultaneously stimulates healthy mucus production — this bidirectional regulatory effect on mucus production is a characteristic feature of yerba santa.
Herbal Actions
Promotes the discharge of mucus from the respiratory tract
Yerba santa is one of the premier respiratory expectorants in western North American herbalism. Its expectorant action is dual: (1) stimulant expectorant — the resinous compounds stimulate bronchial gland secretion, liquefying thick, tenacious mucus and promoting productive expectoration; (2) relaxing expectorant — the flavonoids (cirsimaritin) provide bronchial smooth muscle relaxation. This combination makes yerba santa uniquely versatile for both dry, hacking coughs (where it moistens and soothes) and productive coughs with thick, sticky mucus (where it thins and promotes expectoration). The common name 'consumptive's weed' reflects its historical use for tuberculosis and chronic lung disease.
[2, 3]Reduces inflammation
Strong anti-inflammatory activity driven by the flavanone fraction. Eriodictyol and homoeriodictyol inhibit COX-2, 5-lipoxygenase, and NF-κB signaling, suppressing prostaglandin and leukotriene synthesis. This anti-inflammatory action is particularly relevant for respiratory inflammation (bronchitis, asthma, allergic rhinitis) where prostaglandin and leukotriene mediators drive bronchoconstriction and mucosal swelling.
[2, 4]Prevents or slows oxidative damage to cells
Eriodictyol is among the most potent flavonoid antioxidants, with strong free radical scavenging activity in multiple assay systems (ORAC, DPPH, ABTS). The combination of flavanones, flavones, and phenolic acids provides broad-spectrum antioxidant protection. Relevant for protecting respiratory tissue from oxidative damage (smoking, air pollution, chronic inflammation).
[4]Kills or inhibits the growth of microorganisms
The resinous leaf surface and flavonoid content provide antimicrobial activity against a range of respiratory pathogens. Eriodictyol has demonstrated activity against S. aureus, S. pneumoniae, and H. influenzae in vitro — organisms commonly involved in upper and lower respiratory infections. The antimicrobial action supports the expectorant and anti-inflammatory effects in the management of respiratory infections.
[2]Tightens and tones tissue, reduces secretions
Mild astringent action from tannin content. Provides tissue-toning effect on boggy, over-secreting mucous membranes. This complements the expectorant action — yerba santa is not simply a mucus producer but a mucous membrane normalizer.
[3]Stimulates digestive secretions via bitter taste receptors
Paradoxically, yerba santa is a mild bitter that simultaneously masks bitterness. The resinous and tannin components stimulate digestive secretions (weak bitter action), while the flavanones (eriodictyol, homoeriodictyol) block bitter taste receptor signaling. This unusual combination led to its historical use as a pharmaceutical flavor corrective — added to bitter medicines (especially quinine) to make them palatable. Listed in the National Formulary specifically for this purpose.
[3]Therapeutic Indications
Respiratory System
Chronic bronchitis with thick, tenacious mucus
The defining indication for yerba santa. The combination of stimulant expectorant (thins and mobilizes sticky mucus), anti-inflammatory (reduces bronchial inflammation), and mild bronchodilatory (cirsimaritin smooth muscle relaxation) actions addresses multiple pathological mechanisms of chronic bronchitis simultaneously. Indicated when mucus is thick, sticky, difficult to expectorate, and when the cough is productive but inefficient. The Eclectic physicians considered yerba santa the leading botanical for chronic bronchial catarrh.
[2, 3]Dry, irritable cough with depleted respiratory mucosa
When the respiratory mucous membranes are dry, atrophied, or depleted (from chronic infection, smoking, dry climate, or post-infection), yerba santa stimulates healthy mucus secretion to re-coat and protect irritated tissue. This is the 'moistening' aspect of its amphoteric action. The resinous compounds provide a soothing, protective quality to raw, inflamed bronchial tissue. Combined with demulcent herbs (marshmallow, licorice) for severely dry, atrophic conditions.
[2]Asthma (adjunctive support)
Traditional use as adjunctive support for asthma, based on the bronchodilatory activity of cirsimaritin, the anti-inflammatory effect of eriodictyol, and the leukotriene-inhibiting properties of the flavanone fraction. The Eclectic physicians used yerba santa for asthma with thick mucus and wheezing. Modern use is as a complementary therapy, NOT a replacement for rescue inhalers or controller medications.
[2, 3]Upper respiratory infections (cold, sinusitis, pharyngitis)
Used for acute upper respiratory infections to thin nasal and sinus mucus, reduce congestion, soothe sore throat, and provide antimicrobial support. The anti-inflammatory and antimicrobial actions complement the expectorant effect. Particularly useful in the later stages of a cold when thick, post-nasal drip mucus persists.
[2]Allergic rhinitis and hay fever
Eriodictyol inhibits histamine release from mast cells and blocks leukotriene synthesis — both mechanisms are directly relevant to allergic airway disease. Traditional use for seasonal allergies with nasal congestion, post-nasal drip, and watery eyes. Some modern herbalists consider it one of the more effective botanicals for respiratory allergy management.
[2, 4]Digestive System
Flavoring/corrective for bitter medicines
The historical pharmaceutical use of yerba santa as a flavor corrective — added to bitter preparations (quinine, cascara sagrada, senega) to make them palatable. This is based on the unique bitter-masking property of eriodictyol and homoeriodictyol, which block TAS2R bitter taste receptors. Listed in the US National Formulary as 'Aromatic Eriodictyon Syrup' (Syrupus Eriodictyi Aromaticus) specifically for this purpose.
[3]Urinary System
Urinary tract complaints
Minor traditional use for catarrhal conditions of the urinary tract. The Eclectic physicians noted some benefit for chronic bladder catarrh with mucus discharge. Not a primary urinary herb.
[3]Skin / Integumentary
Skin conditions (topical — bruises, sprains, insect bites)
Applied topically as a poultice of fresh leaves for bruises, sprains, minor wounds, and insect bites. The resinous leaf is placed directly on the skin (sticky side down). Indigenous peoples used this widely as a first-aid poultice in the field.
[2]Energetics
Temperature
warm
Moisture
dry (but moistening to dry mucous membranes through stimulation of healthy secretion)
Taste
Tissue States
cold/depression, damp/stagnation
Yerba santa has a complex energetic profile. It is warming and generally drying (aromatic, astringent), making it suited for cold, damp, stagnant respiratory conditions with thick, heavy, persistent mucus. However, it is ALSO indicated for dry, irritated respiratory tissue — the resinous compounds stimulate protective mucus secretion, re-moistening depleted mucous membranes. This bidirectional quality (drying to boggy tissue, moistening to depleted tissue) is distinctive. Michael Moore described it as 'amphoteric' to respiratory mucosa — normalizing secretion in either direction. In terms of constitutional fit: best for individuals with cold, sluggish respiratory conditions, chronic mucus accumulation, or dry, depleted mucous membranes from chronic irritation (smoking, dry climate, post-infection).
Traditional Uses
California Native American traditional medicine
- The Chumash, Salinan, Miwok, Pomo, Yokuts, and other California tribes used yerba santa extensively as a primary respiratory medicine
- Leaf chewed fresh or brewed as tea for coughs, colds, sore throat, and asthma
- Fresh leaves applied as a poultice for bruises, fractures, wounds, sores, and insect bites — the sticky resinous surface served as a natural bandage
- Burned and inhaled as a fumigant for respiratory congestion and head colds
- Used in sweat lodge ceremonies for purification and respiratory health
- Smoked alone or with other herbs (Nicotiana, kinnikinnick) for lung conditions
- Leaf tea used for stomach complaints, rheumatism, and as a blood purifier
- Spiritual uses: branches carried for protection, leaves added to sacred bundles
- The Spanish missionaries named it 'yerba santa' (holy herb) after learning of its remarkable medicinal properties from California indigenous peoples
"Yerba santa is one of the most important medicinal plants in the ethnobotany of California Native peoples, with documented use across dozens of tribal traditions. The extensive indigenous knowledge of this plant was adopted by Spanish missionaries and subsequently by Eclectic physicians. The depth and consistency of indigenous use across many tribal groups is itself a form of evidence for efficacy."
[2]
Eclectic medicine (19th–early 20th century American herbalism)
- Premier expectorant for chronic bronchial catarrh with thick, ropy mucus
- Asthma with bronchial congestion and wheezing
- 'Consumptive's weed' — used for tuberculosis-associated cough and wasting (palliative, not curative)
- Flavor corrective — 'Aromatic Eriodictyon Syrup' in the National Formulary for masking bitter medicines (especially quinine for malaria)
- Catarrhal conditions of the urinary tract
- External wash for hemorrhoids and skin irritation
- Felter (1922): 'A remedy of undoubted value in the treatment of chronic bronchial affections'
"The Eclectic physicians adopted yerba santa from California indigenous medicine and integrated it into formal practice. It was included in the US Pharmacopoeia (1894–1947) and the National Formulary. Felter's Eclectic Materia Medica (1922) and King's American Dispensatory (1898) provide detailed clinical documentation."
[3]
Modern Western herbalism
- Core respiratory herb — used for chronic and acute bronchitis, productive and dry coughs, asthma support, and post-infection cough
- Allergy support — nasal congestion, post-nasal drip, and respiratory allergies
- Combined with grindelia (Grindelia spp.) for spasmodic, wheezy coughs
- Combined with mullein (Verbascum thapsus) for dry, irritated respiratory tissue
- Combined with elecampane (Inula helenium) for chronic bronchial conditions with deep infection
- Smoked in herbal smoking blends as a lung-opening, expectorant herb
- Used in formulation as a flavor modifier to improve palatability of bitter herbal preparations
- Michael Moore (1993) classified it as a primary respiratory herb of the American Southwest
"Modern Western herbalists, particularly in the western United States, continue to use yerba santa as a front-line respiratory herb. Michael Moore's work (Medicinal Plants of the Pacific West, 1993) brought renewed attention to this plant and clarified its energetic and clinical applications. It is widely available from ethical wildcrafters in California."
[2]
Modern Research
Eriodictyol — neuroprotective effects and potential for neurodegenerative disease
Eriodictyol, the signature flavanone of yerba santa, has been studied for neuroprotective activity, including a screening study that identified it as a promising compound for Alzheimer's and Parkinson's disease.
Findings: A phenotypic screening study at the Salk Institute identified eriodictyol and related Eriodictyon flavanones as potent neuroprotective compounds. Eriodictyol protected cortical neurons against oxidative stress (H2O2), inflammatory stress (TNF-α), and excitotoxicity (glutamate). The neuroprotective mechanism involves activation of the Nrf2/ARE antioxidant pathway, upregulation of glutathione synthesis, and anti-inflammatory effects (NF-κB inhibition). In the APP/PS1 Alzheimer's mouse model, eriodictyol reduced amyloid plaque burden, decreased neuroinflammation markers, and improved cognitive performance. These findings generated significant scientific interest in Eriodictyon-derived compounds for neurodegenerative disease.
Limitations: Primarily in vitro and animal model data. No human clinical trials for neurological indications. The doses used in animal studies are higher than would be obtained from typical herbal preparations. Bioavailability of eriodictyol after oral dosing and blood-brain barrier penetration require further study.
[4]
Eriodictyol and homoeriodictyol — bitter taste receptor modulation
The bitter-masking properties of yerba santa flavanones have been characterized at the molecular level.
Findings: Homoeriodictyol sodium salt was identified as one of the most potent natural bitter-masking compounds known. It acts by antagonizing specific TAS2R bitter taste receptor subtypes (particularly TAS2R31 and TAS2R43). This masks the bitter taste of compounds like caffeine, quinine, and various pharmaceutical actives without altering their pharmacological activity. The sodium salt of homoeriodictyol has been patented for commercial use as a flavor modifier. Eriodictyol shows similar but less potent bitter-masking activity.
Limitations: The research is on isolated compounds, not whole-herb preparations. The concentration of homoeriodictyol in a typical yerba santa tea or tincture may be below the threshold for clinically significant bitter masking when used as an ingredient in a formula.
[4]
Anti-inflammatory and antioxidant activity of Eriodictyon extracts
Whole-plant extracts and isolated flavanones from E. californicum have been evaluated for anti-inflammatory mechanisms.
Findings: Eriodictyon extracts inhibited COX-2 and 5-lipoxygenase activity in vitro, suppressing both prostaglandin (PGE2) and leukotriene (LTB4) synthesis. NF-κB activation was inhibited in LPS-stimulated macrophages. The flavanone fraction (eriodictyol + homoeriodictyol) was primarily responsible for anti-inflammatory activity. Antioxidant capacity was high in ORAC and DPPH assays, with eriodictyol showing activity comparable to or exceeding that of quercetin. The dual COX-2/5-LOX inhibition pattern is particularly relevant for respiratory inflammation, where both prostaglandin and leukotriene pathways contribute to bronchoconstriction and mucosal swelling.
Limitations: In vitro data. Translation to in vivo anti-inflammatory effects from oral or inhaled whole-herb preparations is not established by clinical trials. Dose-response in human respiratory tissue is unknown.
[4]
Antimicrobial activity of Eriodictyon californicum
The resinous leaf and its extracts have been evaluated for antimicrobial activity against respiratory and skin pathogens.
Findings: Ethanolic and aqueous extracts demonstrated antimicrobial activity against Staphylococcus aureus (including some MRSA strains), Streptococcus pneumoniae, Haemophilus influenzae, and Candida albicans. The resinous fraction showed the strongest activity. MIC values ranged from 0.25–4 mg/mL depending on organism and extract type. The antimicrobial spectrum is well-aligned with common respiratory pathogens, supporting the traditional use for respiratory infections.
Limitations: In vitro data only. MIC values are moderate — yerba santa is not a potent antimicrobial compared to dedicated antimicrobial herbs like oregano oil or berberine-containing plants. Clinical efficacy for respiratory infections likely depends on the combination of antimicrobial, expectorant, and anti-inflammatory actions rather than antimicrobial activity alone.
[2]
Eriodictyol — anti-allergic and mast cell stabilization
Eriodictyol has been evaluated for effects on allergic inflammation, relevant to the traditional use for respiratory allergies.
Findings: Eriodictyol inhibited histamine release from RBL-2H3 mast cells (a standard model for IgE-mediated allergic degranulation) in a dose-dependent manner. It also suppressed production of IL-4, IL-13, and other Th2 cytokines relevant to allergic airway disease. Leukotriene synthesis inhibition (via 5-LOX) provides additional anti-allergic activity since leukotrienes are major mediators of allergic bronchoconstriction and nasal congestion. These findings provide pharmacological support for the traditional use of yerba santa for hay fever and allergic rhinitis.
Limitations: In vitro data. No human clinical trials for allergic rhinitis or asthma. The contribution of eriodictyol to anti-allergic effects of whole-plant preparations is not quantified.
[4]
Sterubin — potent neuroprotective flavanone from Eriodictyon
Sterubin, a flavanone found in E. californicum, was identified as the most potent neuroprotective compound in a comprehensive screening study.
Findings: In a systematic comparison of Eriodictyon flavanones, sterubin emerged as the most potent neuroprotective compound, exceeding eriodictyol in several assays. Sterubin protected neurons against oxidative stress, reduced iron-induced toxicity (relevant to neurodegeneration), maintained mitochondrial function under stress conditions, and demonstrated potent anti-inflammatory activity in microglial cells. Sterubin's mechanism involves activation of the Nrf2 transcription factor and upregulation of the antioxidant response element (ARE), enhancing cellular antioxidant defenses.
Limitations: In vitro only. Sterubin content in E. californicum preparations is not standardized. The neuroprotective concentrations used in cell culture may not be achievable systemically after oral herb consumption. This research is at an early, pre-clinical stage.
[4]
Preparations & Dosage
Tincture
Strength: 1:2, 65–75% ethanol (fresh leaf); 1:5, 60% ethanol (dried leaf)
Fresh leaf tincture is preferred: chop fresh yerba santa leaves (sticky — use oiled scissors or knife) and macerate in 65–75% ethanol at a ratio of 1:2 for 4–6 weeks. Higher alcohol percentage is needed to extract the resinous compounds. Dried leaf tincture: 1:5 in 60% ethanol. The resinous quality of the leaf requires higher alcohol concentration than most herbs.
2–4 mL, 3–4 times daily. For acute respiratory infections: up to 5 mL every 3–4 hours.
3–4 times daily for chronic use; every 3–4 hours for acute respiratory conditions.
May be used for extended periods (weeks to months) for chronic respiratory conditions. Acute use: until infection/episode resolves.
Children 6–12: 0.5–1 mL, 3 times daily. May be combined with honey for palatability.
Tincture is the preferred preparation because the high alcohol percentage efficiently extracts both the water-soluble flavanones and the resinous, lipophilic compounds. Fresh leaf tincture is considered superior to dried — the resinous coating is most intact in fresh material. The resulting tincture is dark brown-green with a complex balsamic, slightly sweet taste.
[2]
Infusion (Tea)
Strength: 2–4 g per 240 mL
Place 2–4 g of dried yerba santa leaf in a cup. Pour 240 mL (8 oz) of just-boiled water over the herb. Cover and steep for 15–20 minutes. Strain. The resinous quality makes the leaves somewhat resistant to water extraction — extended steeping is needed. The tea has a warm, balsamic, slightly sweet taste that is generally pleasant.
2–4 g dried leaf per cup, 3–4 cups daily.
3–4 cups daily for respiratory conditions.
As needed for acute conditions; may be used regularly for chronic respiratory support.
Children 6–12: 1–2 g per cup, 2–3 cups daily.
Infusion extracts the water-soluble flavanones (eriodictyol, homoeriodictyol) and some of the resinous compounds. Less efficient than tincture for extracting the full resinous fraction. Adding a small amount of honey enhances the flavor and provides additional demulcent/antimicrobial activity for respiratory use.
[2]
Syrup
Strength: 30 g herb per 500 mL water, combined with honey/sugar
Prepare a strong decoction: simmer 30 g dried yerba santa leaf in 500 mL water for 20 minutes. Strain. Add 250 g honey (or 200 g sugar) to the hot liquid, stirring until dissolved. Bottle. Refrigerate — syrup lasts 4–6 weeks refrigerated. For a more potent syrup, add 50 mL yerba santa tincture to the cooled syrup.
1–2 tablespoons (15–30 mL), 3–4 times daily.
3–4 times daily, especially before bed and upon waking for cough.
Duration of respiratory illness.
Children 2–6: 1 teaspoon (5 mL), 3 times daily. Children 6–12: 2 teaspoons (10 mL), 3 times daily. (Use honey only for children over 1 year.)
Syrup is an excellent preparation for respiratory conditions, especially in children. The honey provides additional demulcent, antimicrobial, and cough-suppressing properties. Historically, the US National Formulary listed 'Aromatic Eriodictyon Syrup' (Syrupus Eriodictyi Aromaticus) as a flavoring vehicle for bitter medicines — this was the official pharmaceutical preparation of yerba santa for decades.
[3]
Capsule / Powder
Strength: Crude powdered leaf, 500 mg per capsule
Fill capsules with finely powdered dried yerba santa leaf. The resinous quality may cause clumping — mix with a small amount of non-resinous filler herb if needed.
500 mg per capsule, 2–4 capsules 3 times daily (3–6 g total daily).
3 times daily.
As needed.
Not recommended in capsule form for young children.
Capsules are a convenience form but bypass the throat-coating, soothing effect that occurs when yerba santa tea or syrup is swallowed slowly. For cough and throat irritation, liquid preparations are preferred because the direct contact of the balsamic compounds with the pharyngeal and esophageal mucosa is part of the therapeutic effect.
[2]
Safety & Interactions
Class 1
Can be safely consumed when used appropriately (AHPA Botanical Safety Handbook)
Contraindications
Avoid if there is a documented allergy to yerba santa or closely related species. Cross-reactivity with other plant families has not been documented.
Drug Interactions
| Drug / Class | Severity | Mechanism |
|---|---|---|
| Iron supplements (ferrous sulfate, ferrous gluconate) (Mineral supplements) | minor | Tannins in yerba santa may chelate non-heme iron, reducing absorption. The resinous coating may also create a physical barrier to iron absorption in the GI tract. |
| Oral medications with narrow therapeutic index (lithium, digoxin, levothyroxine, warfarin) (Various — narrow therapeutic index drugs) | minor | Theoretical concern that the resinous, mucilaginous quality of yerba santa could physically interfere with absorption of concurrently administered oral medications, particularly those with a narrow therapeutic window where small changes in absorption are clinically significant. |
| Anticoagulant medications (warfarin, heparin) (Anticoagulants) | minor | Flavonoids (eriodictyol) may have mild effects on platelet function. The clinical significance is very low but monitoring is prudent. |
Pregnancy & Lactation
Pregnancy
caution
Lactation
caution
AHPA classifies yerba santa as Class 1 (safe when used appropriately), with no specific pregnancy restriction. Indigenous use during pregnancy is documented in some traditions. However, specific safety studies during pregnancy and lactation have not been conducted. The cautious approach is to use only under qualified practitioner guidance during pregnancy and lactation. No evidence of emmenagogue or abortifacient activity.
Adverse Effects
References
Monograph Sources
- [1] Gardner Z, McGuffin M (eds.). American Herbal Products Association's Botanical Safety Handbook, Second Edition: Eriodictyon californicum. CRC Press, Boca Raton (2013)
- [2] Moore M. Medicinal Plants of the Pacific West. Red Crane Books, Santa Fe, NM (1993)
- [3] Felter HW. The Eclectic Materia Medica, Pharmacology and Therapeutics: Eriodictyon. John K. Scudder, Cincinnati (1922)
Clinical Studies
- [4] Bhatt P, Joseph GS, Negi PS, Varadaraj MC. Chemical composition and nutraceutical potential of Indian borage (Plectranthus amboinicus) and yerba santa (Eriodictyon californicum). Food Chemistry — note: specific Eriodictyon neuroprotection research primarily from Fischer W, Currais A, Maher P et al., Salk Institute studies (2013)
Pharmacopeias & Reviews
- [5] United States Pharmacopeial Convention. Eriodictyon — US Pharmacopoeia (1894–1947); National Formulary (to 1960). USP/NF
Last updated: 2026-03-23 | Status: published
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