Herbal Monograph
Hops
Humulus lupulus L.
Cannabaceae
Premier sedative nervine and bitter tonic for insomnia, nervous restlessness,...
Overview
Plant Description
Vigorous, dioecious, herbaceous perennial climbing vine (bine) growing 6-9 m in a single season from a persistent rootstock. Stems (bines) are rough, angular, and covered with hooked climbing hairs (trichomes) that enable clockwise twining around supports. Leaves opposite, palmately 3-5 lobed with serrate margins, 8-15 cm across, rough-textured on both surfaces with glandular dots beneath. Male flowers in loose axillary panicles; female flowers in pendulous catkin-like spikes (strobiles) that develop into the characteristic papery, cone-like infructescences (hop cones), 2-5 cm long, composed of overlapping membranous bracts (stipular bracteoles). At the base of each bract lie the lupulin glands — golden-yellow, resinous glandular trichomes approximately 0.15-0.25 mm in diameter — which contain the essential oils, bitter acids, and prenylated flavonoids that give hops their characteristic bitter aroma and medicinal properties. The rootstock is perennial and can persist for 20+ years under cultivation.
Habitat
Prefers deep, fertile, well-drained loamy soils with pH 6.0-7.5. Requires full sun and ample moisture during the growing season. Naturally found in hedgerows, woodland margins, riverbanks, and thickets in temperate regions. Requires support structures for climbing — commercially trained on wire trellises 5-6 m high. Hardy to USDA zones 3-8. Day-length sensitive; performs best between 35-55 degrees N latitude where long summer days promote cone development.
Distribution
Native to temperate regions of the Northern Hemisphere — Europe, western Asia, and North America. Five taxonomic varieties recognized based on geography: var. lupulus (Europe), var. cordifolius (eastern Asia), var. neomexicanus (southwestern North America), var. pubescens (midwestern North America), and var. lupuloides (eastern North America). Major commercial cultivation regions include Germany (Hallertau region — world's largest hop-growing area), Czech Republic (Saaz/Zatec), United Kingdom (Kent), United States (Pacific Northwest — Yakima Valley, Washington and Willamette Valley, Oregon), and increasingly China, Australia, New Zealand, and South Africa.
Parts Used
Strobile (Lupuli flos — female infructescence/hop cone)
Preferred: Dried strobiles for infusion, tincture, or encapsulated powder; fresh strobiles for tincture; dried strobiles in sleep pillows
The strobile (hop cone) is the official medicinal part recognized by Commission E, EMA/HMPC, and the European Pharmacopoeia (Lupuli flos). The entire strobile is used, including the membranous bracts and the lupulin glands at their bases. The lupulin glands are the primary reservoir of bitter acids (humulone, lupulone), essential oils (humulene, myrcene), and prenylated flavonoids (xanthohumol, 8-prenylnaringenin) responsible for the sedative, estrogenic, and bitter tonic actions. Strobiles are used dried for infusions and tinctures, or as powdered material in capsules and tablets.
Lupulin (Lupulinum — separated glandular trichomes)
Preferred: Powdered lupulin in capsules or incorporated into ointments (historical); rarely used as a standalone preparation in modern practice
Lupulin is the concentrated resinous powder obtained by sifting or mechanically separating the glandular trichomes from dried hop strobiles. It represents the concentrated active fraction and was listed in the USP as an official preparation (Lupulinum) from 1831 to 1916. Contains a higher concentration of bitter acids and essential oils than whole strobiles. Used historically as a more potent sedative preparation but less commonly employed in modern practice due to difficulties in standardization and rapid oxidative degradation.
Key Constituents
Bitter acids (acylphloroglucinol derivatives)
The bitter acid fraction is central to hops' dual action as a sedative nervine and digestive bitter. Fresh bitter acids stimulate appetite and gastric secretion through their intense bitterness (bitter tonic action). During storage, oxidative degradation of these same bitter acids generates 2-methyl-3-buten-2-ol, the principal sedative compound, which enhances GABA-A receptor activity. This means that for sedative/sleep indications, properly stored or aged hop preparations may be more effective than freshly prepared ones. Commission E and EMA recognize both the sedative and digestive bitter actions.
Prenylated flavonoids (prenylflavonoids)
The prenylated flavonoid fraction is responsible for the estrogenic, anti-inflammatory, and potential chemopreventive activities of hops. 8-Prenylnaringenin is the most clinically significant constituent in this class due to its potent phytoestrogenic activity, relevant to menopausal symptom relief and the AHPA Class 2b safety classification. Xanthohumol has attracted considerable research interest as an anti-inflammatory and anticancer compound, though clinical evidence in humans remains preliminary. The variable in vivo conversion of isoxanthohumol to 8-prenylnaringenin by gut microbiota introduces significant inter-individual variability in estrogenic response.
Volatile oil (essential oil)
Essential oil yield is 0.3-1.0% from dried strobiles (higher than most medicinal herbs). The volatile oil contributes to the sedative and anti-inflammatory actions of hops. Myrcene and humulene are the major constituents with demonstrated sedative and anti-inflammatory properties in animal models. The essential oil acts synergistically with the bitter acids and flavonoids to produce the overall pharmacological profile. The aromatic volatile compounds are responsible for the traditional use of hop pillows, where inhalation of volatile constituents contributes to sleep promotion.
Other constituents
Minor constituents that provide ancillary therapeutic effects. Tannins contribute astringent and mild antimicrobial activity relevant to the digestive bitter action. The overall resinous nature of hops (15-30% total resins) means that ethanol-based extracts and lipophilic preparations capture a broader spectrum of active constituents than aqueous infusions alone.
Herbal Actions
The most well-established and clinically important action. Commission E approved for sleep disturbances. EMA traditional use monograph for sleep disorders. The sedative mechanism involves potentiation of GABA-A receptor activity by 2-methyl-3-buten-2-ol (formed from bitter acid degradation during storage) and possibly by the volatile terpenes (myrcene). Animal studies confirm dose-dependent sedative and hypnotic effects — hop extracts prolong pentobarbital sleeping time in rats. Clinical evidence is strongest for the Valerian-Hops combination (Ze 91019), which significantly reduced sleep latency compared to placebo in a RCT. Hops alone have less robust clinical evidence for sedation but are consistently used in traditional practice and approved by regulatory bodies based on long-standing traditional use.
[1, 2, 8, 12]Reduces nervous tension, restlessness, and anxiety. Commission E approved for mood disturbances including restlessness and anxiety. Hops calms nervous excitability and irritability, making it appropriate for tension-related conditions beyond insomnia — including nervous headache, nervous indigestion, and stress-related irritability. Hoffmann classifies hops as a nervine that 'may be used where stress and tension produce restlessness, headache, and possibly indigestion.'
[1, 2, 3]The intensely bitter taste of hops (bitter value approximately 15,000 — among the most bitter of medicinal herbs) stimulates appetite and promotes gastric secretion via the cephalic-vagal reflex triggered by bitter taste receptor activation. The bitter acids (humulone, lupulone) stimulate bile flow and improve digestive function. This action is well established in traditional European herbalism and forms the pharmacological basis for the centuries-old use of hops in brewing (originally as a preservative and digestive bitter in beer). The BHP lists hops as a bitter tonic for anorexia and dyspepsia.
[3, 4, 6]Relieves smooth muscle spasm
Spasmolytic activity on smooth muscle, particularly relevant to the gastrointestinal tract. Reduces intestinal cramping and spasm associated with nervous dyspepsia and irritable bowel conditions. The combination of antispasmodic and bitter tonic actions makes hops effective for the 'tense and churning' gut associated with anxiety and stress.
[3, 4]8-Prenylnaringenin, identified as the most potent phytoestrogen known, selectively activates ER-alpha. This action was historically observed in menstrual disturbances among female hop pickers. Clinical trials have demonstrated reduction in menopausal hot flashes with standardized hop extracts. However, the concentration of 8-PN in standard herbal preparations (infusions, tinctures) is very low, and the clinical significance of estrogenic activity at typical medicinal doses remains debated. In vivo conversion of the more abundant isoxanthohumol to 8-PN by intestinal microbiota adds to estrogenic exposure but is highly variable between individuals.
[4, 10, 13]Kills or inhibits the growth of microorganisms
Bitter acids, particularly lupulone (beta-acids), demonstrate significant antimicrobial activity against Gram-positive bacteria including Staphylococcus aureus, Streptococcus mutans, and Mycobacterium tuberculosis. This is the basis for the historical use of hops as a beer preservative (predating the recognition of sedative properties). Activity against Gram-negative organisms and fungi is weaker. Clinical relevance as a standalone antimicrobial agent is limited, but the action contributes to the herb's utility in digestive formulas.
[4, 18]Traditional reputation for reducing sexual excitability, particularly in men. Documented in European traditional herbalism and cited by Grieve (1931). The mechanism may relate to the combined sedative, estrogenic, and cooling-bitter actions. Used traditionally in monastic settings as an anti-aphrodisiac. Clinical evidence is limited to traditional reports; no controlled studies exist.
[3, 17]Reduces inflammation
Xanthohumol and humulene demonstrate anti-inflammatory activity in vitro and in animal models through inhibition of NF-kB, COX-2, and iNOS. Topical anti-inflammatory use is documented in traditional herbalism for skin conditions and joint pain. The anti-inflammatory action supplements the primary sedative and bitter tonic actions but is not the principal clinical application.
[4, 18]Therapeutic Indications
Nervous System
Insomnia and sleep disturbances
Commission E approved indication. EMA traditional use monograph for 'relief of mild symptoms of mental stress and to aid sleep.' The sedative-hypnotic action operates through GABA-A receptor modulation by 2-methyl-3-buten-2-ol. Most robust clinical evidence exists for the Valerian-Hops combination (Ze 91019), which demonstrated significant reduction in sleep latency versus placebo in a 4-week RCT. The Morin et al. (2005) multicenter RCT of 184 adults with mild insomnia showed the valerian-hops combination improved sleep quality and quality of life over 28 days. Hops is most effective for difficulty falling asleep (prolonged sleep latency) rather than difficulty staying asleep.
[1, 2, 8, 9]Restlessness and nervous tension
Commission E approved for 'mood disturbances such as restlessness and anxiety.' EMA monograph supports traditional use for 'relief of mild symptoms of mental stress.' Hops calms nervous hyperexcitability and reduces restless agitation. Particularly indicated where nervousness manifests as irritability, inability to relax, and physical restlessness (fidgeting, tossing, pacing). Often combined with valerian, passionflower, or lemon balm in anxiolytic formulas.
[1, 2, 3]Mild anxiety
The nervine relaxant action supports use in mild anxiety states. Animal studies demonstrate anxiolytic activity of hop bitter acid extracts. Franco et al. (2012) demonstrated that non-alcoholic beer with hops reduced anxiety in a university-student stress model. Clinical evidence for hops as a standalone anxiolytic is limited but the traditional use is well documented and pharmacologically plausible given the GABA-ergic mechanism.
[1, 3, 15]Nervous headache
Traditional use for tension headaches associated with stress and nervous excitability. Hoffmann recommends hops where 'stress and tension produce restlessness, headache, and possibly indigestion.' The combined sedative and antispasmodic actions provide rationale. No controlled clinical evidence specific to headache.
[3]gastrointestinal
Anorexia and poor appetite
BHP indication. The intense bitterness of hops (bitter value ~15,000) triggers the cephalic-vagal reflex, stimulating appetite and gastric secretion. Particularly indicated when poor appetite is associated with nervous tension or convalescence. Standard application as a bitter tonic taken 15-30 minutes before meals.
[3, 4, 6]Nervous dyspepsia and irritable bowel
The combination of bitter tonic, antispasmodic, and nervine relaxant actions makes hops particularly effective for digestive complaints driven by nervous tension — the 'butterflies in the stomach' pattern. Reduces intestinal cramping and spasm while simultaneously calming the nervous system that drives the gut dysfunction. Hoffmann specifically recommends hops for this presentation.
[3, 4, 6]Intestinal cramping and colic
Antispasmodic action on intestinal smooth muscle provides symptomatic relief of cramping. Traditional use in combination with chamomile, peppermint, or valerian for spasmodic digestive complaints.
[3]endocrine-reproductive
Menopausal symptoms (hot flashes, vasomotor symptoms)
The phytoestrogenic activity of 8-prenylnaringenin provides a pharmacological basis for use in menopausal symptom relief. Heyerick et al. (2006) conducted a prospective RCT of 67 menopausal women with a standardized hop extract (100 micrograms 8-PN/day); significant improvement in menopausal discomforts was observed at 6 weeks versus placebo (P=0.023). Erkkola et al. (2010) confirmed reduction in hot flash frequency in a crossover pilot study. However, longer-term efficacy data are limited, and the very low concentration of 8-PN in standard herbal preparations (infusions, tinctures) versus standardized extracts raises questions about whether traditional preparations deliver clinically significant estrogenic doses.
[10, 11, 13]Menstrual irregularities (excess sexual excitability)
Traditional European use based on centuries of observation of menstrual disturbances in female hop pickers ('hop-picker's disease'). The estrogenic and anaphrodisiac actions were recognized empirically long before the identification of 8-prenylnaringenin. Traditional use for reducing excessive libido in both sexes. Clinical evidence limited to historical reports and the modern identification of the phytoestrogenic mechanism.
[16, 17]Musculoskeletal System
Muscle tension and pain (topical)
Traditional topical application of hop poultices for muscle tension, neuralgia, and rheumatic pain. The anti-inflammatory (humulene, xanthohumol) and analgesic (myrcene) properties of the volatile oil provide pharmacological rationale. External use only for this indication.
[3, 17]Energetics
Temperature
cool
Moisture
dry
Taste
Tissue States
hot/excitation, tense/constriction, damp/stagnation
Hops is cooling and drying in Western energetic assessment. Its pronounced bitterness is the dominant taste, classifying it among the most intensely bitter herbs in the materia medica. The cooling nature makes it specific for 'hot-type' insomnia — restless, irritable, overheated individuals who cannot switch off a racing mind. Peter Holmes (The Energetics of Western Herbs) emphasizes this cooling quality. The bitter and pungent tastes support digestive function by stimulating secretions and moving stagnation. The drying quality acts on damp, congestive states in the gut. Traditional energetic caution: hops is contraindicated in 'cold depression' — individuals with marked melancholy, lethargy, and cold constitutions, as the cooling nature may exacerbate these states. This is the basis for the traditional warning against using hops in depressive conditions.
Traditional Uses
European traditional herbalism
- Sleep aid — hop pillows (sachets of dried strobiles placed under the pillow) for insomnia
- Nervine sedative for restlessness, anxiety, and nervous excitability
- Bitter tonic for poor appetite and sluggish digestion
- Anaphrodisiac for excessive sexual excitability
- Topical poultice for boils, ulcers, and painful swellings
- Infusion for nervous headache and neuralgia
"Hoffmann (2003): 'Hops is a remedy that has a long history of use for sleeping problems. It may be used where stress and tension produce restlessness, headache, and possibly indigestion. It is a mild sedative and hypnotic, valuable in the treatment of insomnia. Its bitter principles make it useful in improving appetite and digestion.' Grieve (1931): 'A pillow of warm Hops will often relieve toothache and earache and allay nervous irritation... The Lupulin is used in medicine more frequently than the strobiles themselves. It is in the British Pharmacopoeia... It has tonic, nervine, diuretic and anodyne properties.'"
German phytotherapy (Commission E / EMA)
- Mood disturbances such as restlessness and anxiety
- Sleep disturbances (insomnia)
- Combined with Valerian root for sleep disorders (EMA combination monograph)
"Commission E approved hops for 'mood disturbances (restlessness, anxiety) and sleep disturbances.' Single dose of 500 mg dried herb. EMA HMPC concluded that hop strobile preparations can be applied for 'the relief of mild symptoms of mental stress and to aid sleep' based on long-standing traditional use. The EMA also issued a separate combination monograph for Valeriana officinalis radix and Humulus lupulus flos."
Eclectic medicine (American)
- Nervine and sedative for insomnia and delirium tremens
- Bitter tonic for dyspepsia and loss of appetite
- Anodyne for pain and neuralgia
- Diuretic for urinary complaints
- Topical application for ulcers and tumors
"Felter and Lloyd (King's American Dispensatory, 1898): 'Hops are tonic, hypnotic, febrifuge, anthelmintic, and diuretic... Hops are principally employed to produce sleep and allay pain... The Lupulin is the most active preparation, and is decidedly hypnotic and sedative. It allays pain without constipating. It is useful in nervous irritability, sleeplessness, and delirium tremens... As a tonic it may be used in all cases of enfeebled digestion.'"
[16]
Native American medicine
- Sedative and sleep aid
- Remedy for toothache and earache (topical poultice)
- Treatment for indigestion and nausea
- Anti-inflammatory for general inflammation
"Several Native American tribes independently used North American wild hops (Humulus lupulus var. lupuloides and var. neomexicanus) medicinally. The Delaware and Cherokee used hops as a sedative and sleep aid. The Fox and Meskwaki used hop poultices for toothache. Uses were independently documented before European contact, suggesting parallel discovery of the plant's sedative and analgesic properties."
[18]
Medieval European (monastic) herbalism
- Preservative and flavoring agent in beer (primary historical use from ~800 CE)
- Sedative for monastic use (anaphrodisiac to reduce carnal temptation)
- Treatment for leprosy and digestive ailments
"Hildegard of Bingen (1098-1179) was an early advocate of hop cultivation, noting that hops 'when put in beverages, stops putrefaction' and referencing its preservative qualities. The observation that brewery workers tended to fall asleep on the job contributed to the recognition of hops' sedative properties. The monastic use of hops as an anaphrodisiac to quell sexual desire was a significant factor in its adoption in European monasteries."
[18]
Modern Research
Valerian-Hops combination for sleep disorders
Randomized, double-blind, placebo-controlled clinical trial (Ze 91019) demonstrating that the fixed valerian-hops combination significantly reduced sleep latency in patients with non-organic insomnia.
Findings: Koetter et al. (2007) conducted a 4-week RCT comparing placebo, single valerian extract (Ze 911), and fixed valerian-hops extract combination (Ze 91019) in patients with non-organic insomnia (ICD-10 F51.0-F51.2). Inclusion required sleep latency of 30 minutes or more. The fixed valerian-hops combination was significantly superior to placebo in reducing sleep latency. Notably, the single valerian extract failed to show superiority over placebo. This result underlines the contribution of hops to the sedative effect and supports the traditional practice of combining these two herbs.
Limitations: Sleep measurements were by portable home recording device (QUISI), not polysomnography. Sample size was moderate. The study design tested the combination vs. valerian alone, not hops alone.
[8]
Valerian-Hops combination: multicenter RCT
Large multicenter RCT comparing valerian-hops, diphenhydramine, and placebo for mild insomnia.
Findings: Morin et al. (2005) randomized 184 adults with mild insomnia across 9 US sleep centers to valerian-hops combination, diphenhydramine, or placebo for 28 days. The valerian-hops combination showed modest improvements in subjective sleep parameters. Patients in the valerian-hops group rated insomnia severity significantly lower than placebo at 14 days, and quality of life (physical component) was significantly improved at 28 days. Importantly, there were no significant residual effects, no serious adverse events, and no rebound insomnia upon discontinuation — advantages over conventional hypnotics.
Limitations: Subjective outcome measures (self-report sleep diaries). Few individual comparisons with placebo reached statistical significance. Effect sizes were modest. The study population had mild insomnia, limiting generalizability to more severe sleep disorders.
[9]
Sedative mechanism: GABA-A receptor modulation
Investigation of the sedating effects of hop extracts and identification of 2-methyl-3-buten-2-ol as the primary sedative compound.
Findings: Schiller et al. (2006) demonstrated that hop strobile extracts exert sedative and hypnotic properties in mice at doses of 100-250 mg/kg. Hop extracts prolonged pentobarbital sleeping time without affecting latency to loss of righting reflex, confirming hypnotic rather than anesthetic properties. The sedative activity correlated with the content of 2-methyl-3-buten-2-ol, a degradation product of bitter acids formed during storage. This compound enhances GABA-A receptor activity, providing a molecular mechanism consistent with the observed sedative-hypnotic effects.
Limitations: Animal model (mice). Dose extrapolation to human clinical use is indirect. The role of other constituents (essential oil terpenes, intact bitter acids) in the overall sedative effect was not fully dissected.
[12]
Phytoestrogenic activity and menopausal symptoms
First prospective RCT of standardized hop extract for menopausal discomforts, demonstrating short-term efficacy via the phytoestrogen 8-prenylnaringenin.
Findings: Heyerick et al. (2006) conducted a prospective, randomized, double-blind, placebo-controlled study of 67 menopausal women over 12 weeks. A hop extract standardized to 100 micrograms 8-prenylnaringenin per day was significantly superior to placebo after 6 weeks (P=0.023), particularly for reduction in hot flash frequency. However, the difference did not maintain statistical significance at 12 weeks (P=0.086), possibly due to a rising placebo response. The higher dose arm (250 micrograms 8-PN) did not show dose-dependent improvement.
Limitations: Small sample size (n=67). Loss of significance at 12 weeks raises questions about sustained efficacy. High placebo response typical of menopause trials. The 250-microgram dose arm did not outperform the 100-microgram arm, which is unexpected if the effect is dose-dependent.
[10]
Identification of 8-prenylnaringenin as a potent phytoestrogen
Landmark identification of 8-prenylnaringenin from hops as the most potent phytoestrogen known, explaining the traditional observation of menstrual disturbances in female hop pickers.
Findings: Milligan et al. (1999) identified 8-prenylnaringenin in hops and demonstrated that it is 50-100 times more potent than the soy isoflavone genistein in competitive estrogen receptor binding assays. 8-PN selectively activates ER-alpha over ER-beta. This finding provided the first molecular explanation for the centuries-old observation of menstrual irregularities in women working in hop fields ('hop-picker's disease'). Subsequent work by Possemiers et al. (2006) demonstrated that gut microbiota can convert the more abundant isoxanthohumol to 8-PN, increasing total estrogenic exposure from hop consumption.
Limitations: In vitro receptor binding assay. The clinical significance of estrogenic activity at typical dietary or medicinal doses remains debated. Inter-individual variability in gut microbial conversion of isoxanthohumol to 8-PN complicates dose-response predictions.
[13]
CYP450 enzyme inhibition by hop prenylphenols
In vitro and clinical evaluation of hop constituents' effects on cytochrome P450 drug-metabolizing enzymes.
Findings: Henderson et al. (2014) demonstrated potent in vitro inhibition of CYP2C family enzymes by hop prenylated compounds: CYP2C8 (93% inhibition), CYP2C9 (88%), CYP2C19 (70%), and CYP1A2 (27%). Isoxanthohumol was the most potent inhibitor of CYP2C8, while 8-prenylnaringenin most potently inhibited CYP1A2, CYP2C9, and CYP2C19. However, a subsequent clinical pharmacokinetic study in perimenopausal women consuming hop extract for 2 weeks showed only modest in vivo effects — alprazolam AUC increased by 7.6%, suggesting minor inhibition of CYP3A4/5. The discrepancy between potent in vitro inhibition and modest in vivo effects suggests that bioavailable concentrations of hop prenylphenols at standard doses may not reach clinically significant inhibitory levels for most CYP enzymes.
Limitations: In vitro study showing potent inhibition may not translate to clinically significant interactions at standard herbal doses. The clinical pharmacokinetic study was reassuring but used a limited panel of probe drugs and a small sample size.
[14]
Xanthohumol anticancer and anti-inflammatory activity
Comprehensive review of xanthohumol's broad-spectrum anticancer and anti-inflammatory mechanisms in preclinical models.
Findings: Xanthohumol has demonstrated antiproliferative activity against multiple cancer cell lines including breast, prostate, colon, liver, lung, and leukemia cells. Mechanisms include inhibition of NF-kB, PI3K/Akt/mTOR, STAT3, and HIF-1alpha signaling pathways. Anti-inflammatory activity includes suppression of COX-2, iNOS, and pro-inflammatory cytokines. Xanthohumol is considered one of the most promising cancer chemopreventive compounds from dietary sources.
Limitations: Evidence is almost entirely preclinical (in vitro and animal models). No human clinical trials for cancer prevention or treatment have been completed. Bioavailability of xanthohumol from oral hop preparations is uncertain. The concentrations used in in vitro studies may not be achievable in vivo.
[18]
Preparations & Dosage
Infusion (Tea)
Strength: 0.5-1 g dried strobiles per 250 mL water
Pour 250 mL boiling water over 1-2 teaspoons (0.5-1 g) of dried hop strobiles. Cover immediately to prevent volatile oil loss and steep for 10-15 minutes. Strain. The infusion is intensely bitter and may be combined with honey, lemon balm, or chamomile to improve palatability.
0.5-1 g dried strobiles per cup. Commission E single dose: 500 mg dried herb.
1-3 times daily for anxiety/restlessness; single dose 30-60 minutes before bedtime for insomnia; before meals for digestive bitter action
2-4 weeks for sleep disorders, then reassess. May be used longer term under practitioner supervision.
Not recommended for children under 12 years without practitioner guidance due to estrogenic activity
Aqueous infusion extracts the water-soluble bitter principles, some flavonoids, and tannins but does not efficiently extract the lipophilic prenylated flavonoids (xanthohumol, 8-prenylnaringenin) or the full bitter acid complement. For sedative purposes, the infusion should be prepared from properly stored (not fresh) hops, as the sedative compound 2-methyl-3-buten-2-ol forms during storage. The intensely bitter taste is functional — it triggers the bitter-receptor-mediated digestive response — but many patients find it unpalatable. Covering during steeping is essential to retain volatile aromatic compounds.
Tincture
Strength: 1:5 dried strobiles in 60% ethanol; 1:2 fresh strobiles in 70-90% ethanol
Macerate dried hop strobiles in 60% ethanol at a ratio of 1:5 for 2-4 weeks. Press and filter. Fresh hop tincture may be prepared at 1:2 in 70-90% ethanol.
1-4 mL of 1:5 tincture (in 60% ethanol), 3 times daily for anxiety/nervousness; 2-4 mL as a single dose before bed for insomnia. Weekly maximum approximately 40 mL.
3 times daily for nervous tension; single dose before bed for sleep; before meals for digestive action
2-4 weeks, then reassess
Not recommended under 12 years without practitioner guidance
Tincture is the preferred preparation for many herbalists as it captures both water-soluble and lipophilic constituents (bitter acids, prenylated flavonoids, essential oils) more effectively than aqueous infusion. The ethanol also provides a vehicle for the resinous, poorly water-soluble bitter acids. The bitter taste is concentrated but the small volume (1-4 mL) makes it more tolerable than a full cup of infusion. For sleep, tincture can be taken in a small amount of warm water 30-60 minutes before bed.
capsule/tablet
Strength: 500 mg dried herb per capsule (typical); standardized extracts vary by manufacturer
Powdered dried hop strobiles or standardized hop extract encapsulated in gelatin or vegetable capsules. Commercial preparations often combine hops with valerian root extract.
500-1000 mg dried hop strobile powder per dose. For Valerian-Hops combinations: typically 120-500 mg valerian extract with 60-250 mg hop extract per dose (varies by product; Ze 91019 standardized combination is well-studied).
1-2 doses daily; for insomnia, 30-60 minutes before bedtime
2-4 weeks as a course, reassess. Clinical trials have used 28-day courses.
Not recommended under 12 years
Capsules avoid the intensely bitter taste, which is an advantage for patient compliance but eliminates the bitter-receptor-mediated digestive stimulation that occurs with oral tasting. For digestive indications, liquid preparations (infusion, tincture) that contact the tongue are preferred. For sleep and anxiety indications, capsules are appropriate. The Valerian-Hops combination (Ze 91019) is the most clinically studied formulation and is available in many European countries as an OTC sleep aid.
topical
Strength: 100-300 g dried strobiles per pillow
Hop pillow: Fill a small cloth sachet (10x15 cm) with 100-300 g of dried hop strobiles. Place inside or under the regular pillow. Replace hops every 2-4 weeks as aromatic potency fades. For poultice: Apply warmed, moistened dried hops directly to the affected area (muscle tension, neuralgia). Cover with a cloth.
Hop pillow: use nightly as needed. Poultice: apply to affected area 2-3 times daily.
Nightly for sleep (pillow); as needed for pain (poultice)
As needed
Hop pillow may be used for children over 3 years (keep away from infant faces). Poultice: suitable for children.
The hop pillow is one of the oldest and most distinctive herbal sleep remedies. The volatile terpenes (myrcene, humulene) are released during the night and inhaled, contributing to the sedative effect. The sedative compound 2-methyl-3-buten-2-ol also becomes more concentrated as the hops age in the pillow. King George III of England was reportedly prescribed a hop pillow for his insomnia. Hop pillows remain a gentle, non-ingested option for sleep support, especially for children and the elderly. Lightly moistening the hops with a small amount of glycerin or alcohol before filling the pillow can help maintain aromatic release.
liquid-extract
Strength: 1:1 liquid extract in 45-60% ethanol
Liquid extract (1:1) in 45-60% ethanol. Commercially available standardized liquid extracts may be standardized to bitter acid content or 2-methyl-3-buten-2-ol.
0.5-2 mL, 1-3 times daily
1-3 times daily; single dose before bed for sleep
2-4 weeks, then reassess
Not recommended under 12 years without practitioner guidance
More concentrated than tincture. Appropriate when a smaller volume is desired. Ensure adequate ethanol concentration to dissolve the resinous bitter acids.
Safety & Interactions
Class 2b
Not to be used during lactation (AHPA Botanical Safety Handbook)
Contraindications
8-Prenylnaringenin is the most potent known phytoestrogen, with selective ER-alpha agonist activity. Although present at low concentrations in standard preparations, the potential for estrogenic stimulation contraindicates use in patients with estrogen-dependent conditions. This contraindication underlies the AHPA Botanical Safety Handbook Class 2b classification. Mills & Bone (2013) recommend avoiding hops in patients with hormone-sensitive cancers or conditions where estrogenic stimulation could worsen pathology.
Traditional energetic caution: hops' cooling, bitter, and sedative nature may exacerbate depressive states in individuals with cold, melancholic constitutions. This is a traditional contraindication widely cited in Western herbalism (Hoffmann, Grieve) rather than one based on clinical trial data. Not applicable to mild, transient low mood associated with insomnia or anxiety.
Drug Interactions
| Drug / Class | Severity | Mechanism |
|---|---|---|
| Sedative-hypnotic medications (benzodiazepines, zolpidem, barbiturates) (CNS depressants) | moderate | Additive GABA-ergic sedation. 2-Methyl-3-buten-2-ol from hops modulates GABA-A receptors through a mechanism similar to benzodiazepines. Concurrent use may produce excessive sedation. |
| Estrogen-containing medications (oral contraceptives, HRT) (Hormonal medications) | moderate | 8-Prenylnaringenin has potent ER-alpha agonist activity. Theoretical additive estrogenic effect with exogenous estrogen therapy. |
| CYP2C substrates (warfarin, phenytoin, diclofenac) (CYP2C8/2C9/2C19 substrates) | theoretical | In vitro, hop prenylated phenols potently inhibit CYP2C8 (93%), CYP2C9 (88%), and CYP2C19 (70%). Could theoretically increase plasma levels of CYP2C substrates. However, a clinical pharmacokinetic study found only modest in vivo effects, suggesting that bioavailable concentrations at standard doses may not reach inhibitory thresholds. |
| Alcohol (ethanol) (CNS depressant) | moderate | Additive CNS depression. Both hops and alcohol enhance GABAergic inhibition. |
Pregnancy & Lactation
Pregnancy
possibly unsafe
Lactation
insufficient data
Not recommended during pregnancy due to the potent phytoestrogenic activity of 8-prenylnaringenin (ER-alpha agonist). While the concentration of 8-PN in standard preparations is low, the precautionary principle applies given the potential for hormonal disruption during pregnancy. The EMA monograph does not recommend use during pregnancy and lactation due to insufficient safety data. The AHPA Class 2b classification reflects the estrogenic concern. The traditional emmenagogue-like reputation (menstrual-disrupting effects observed in hop pickers) reinforces caution. During lactation, insufficient data exists on excretion of hop constituents into breast milk; avoid use until safety data is available.
Adverse Effects
References
Monograph Sources
- [1] Blumenthal, M., Busse, W.R., Goldberg, A., et al.. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council / Integrative Medicine Communications (1998) . ISBN: 978-0965555500
- [2] Committee on Herbal Medicinal Products (HMPC). Community herbal monograph on Humulus lupulus L., flos (Revision 1). European Medicines Agency (2014)
- [3] Hoffmann, D.. Medical Herbalism: The Science and Practice of Herbal Medicine. Healing Arts Press (2003) . ISBN: 978-0892817498
- [4] Mills, S., Bone, K.. Principles and Practice of Phytotherapy: Modern Herbal Medicine (2nd edition). Churchill Livingstone / Elsevier (2013) . ISBN: 978-0443069925
- [5] Gardner, Z., McGuffin, M. (eds.). American Herbal Products Association's Botanical Safety Handbook (2nd edition). CRC Press (2013) . ISBN: 978-1466516946
- [6] British Herbal Medicine Association. British Herbal Pharmacopoeia. BHMA (1983)
- [7] Brinker, F.. Herbal Contraindications and Drug Interactions (4th edition). Eclectic Medical Publications (2010) . ISBN: 978-1888483147
Clinical Studies
- [8] Koetter, U., Schrader, E., Kaufeler, R., et al.. A randomized, double blind, placebo-controlled, prospective clinical study to demonstrate clinical efficacy of a fixed valerian hops extract combination (Ze 91019) in patients suffering from non-organic sleep disorder. Phytotherapy Research (2007) ; 21 : 847-851 . DOI: 10.1002/ptr.2167 . PMID: 17486686
- [9] Morin, C.M., Koetter, U., Bastien, C., et al.. Valerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trial. Sleep (2005) ; 28 : 1465-1471 . DOI: 10.1093/sleep/28.11.1465 . PMID: 16335333
- [10] Heyerick, A., Vervarcke, S., Depypere, H., et al.. A first prospective, randomized, double-blind, placebo-controlled study on the use of a standardized hop extract to alleviate menopausal discomforts. Maturitas (2006) ; 54 : 164-175 . DOI: 10.1016/j.maturitas.2005.10.005 . PMID: 16321485
- [11] Erkkola, R., Vervarcke, S., Vansteelandt, S., et al.. A randomized, double-blind, placebo-controlled, cross-over pilot study on the use of a standardized hop extract to alleviate menopausal discomforts. Phytomedicine (2010) ; 17 : 389-396 . DOI: 10.1016/j.phymed.2010.01.007 . PMID: 20167461
- [12] Schiller, H., Forster, A., Vonhoff, C., et al.. Sedating effects of Humulus lupulus L. extracts. Phytomedicine (2006) ; 13 : 535-541 . DOI: 10.1016/j.phymed.2006.01.013 . PMID: 16785042
- [13] Milligan, S.R., Kalita, J.C., Heyerick, A., et al.. Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beer. Journal of Clinical Endocrinology & Metabolism (1999) ; 84 : 2249-2252 . DOI: 10.1210/jcem.84.6.5887 . PMID: 10372741
- [14] Henderson, M.C., Miranda, C.L., Stevens, J.F., et al.. In vitro inhibition of human P450 enzymes by prenylated flavonoids from hops, Humulus lupulus. Xenobiotica (2014) ; 44 : 269-275 . DOI: 10.3109/00498254.2013.820007 . PMID: 24342125
- [15] Franco, L., Sanchez, C., Bravo, R., et al.. The sedative effects of hops (Humulus lupulus), a component of beer, on the activity/rest rhythm. Acta Physiologica Hungarica (2012) ; 99 : 133-139 . DOI: 10.1556/APhysiol.99.2012.2.6 . PMID: 22849837
Traditional Texts
- [16] Felter, H.W., Lloyd, J.U.. King's American Dispensatory (18th edition, 3rd revision). Ohio Valley Company (1898)
- [17] Grieve, M.. A Modern Herbal. Jonathan Cape / Harcourt Brace (1931)
- [18] Zanoli, P., Zavatti, M.. Pharmacognostic and pharmacological profile of Humulus lupulus L.. Journal of Ethnopharmacology (2008) ; 116 : 383-396 . DOI: 10.1016/j.jep.2008.01.011 . PMID: 18308492
Pharmacopeias & Reviews
- [19] European Pharmacopoeia Commission. European Pharmacopoeia — Lupuli flos (Hop Strobile). Council of Europe / EDQM (2023)
Last updated: 2026-03-02 | Status: review
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