Hops
Humulus lupulus
Description
overall appearance
A vigorous perennial climbing bine (twines clockwise on its own stem rather than via tendrils) reaching 6β10 m in a single season. Female plants produce the commercially significant papery cone-like strobiles. Dies back to the rootstock each winter and regenerates each spring.
roots
Deep, spreading rhizomatous root system that can spread 1β2 m laterally; roots are fleshy, pale brown; primary commercial propagation is from root cuttings
stem
Tough, rough-textured bine with downward-pointing hooked hairs (bristles); clockwise twining; 4β6 m in one season to 10 m under ideal conditions; dies back to crown each fall
leaves
Opposite, petiolate, palmately 3β5 lobed, 7β14 cm wide; lobes ovate with acuminate tips and coarsely serrate margins; rough, scratchy texture due to stiff hairs on both surfaces; deep green
flowers
Dioecious; female flowers are inconspicuous, developing into cone-like strobiles (hops) 2.5β5 cm long; male flowers in loose panicles; blooms JulyβAugust
fruits/seeds
Strobiles (seed cones): papery, overlapping bracts (bracteoles) enclosing tiny achenes; at base of bracteoles are yellow lupulin glands containing the resinous bitter acids and essential oils
Active Compounds
Traditional Uses
- European monastic brewing tradition used hops since 9th century CE to preserve beer and add bitterness; previously gruit herb blends were used
- German folk medicine used hops in sleep pillows for insomnia since the Middle Ages; pickers noted somnolence from contact with lupulin
- English herbalists including Nicholas Culpeper (1653) recommended hops for insomnia, nervous tension, and digestive complaints
- Traditional use in European folk medicine for anxiety, irritability, and restlessness, often combined with valerian
- Used as a bitter digestive tonic in German and Swiss traditional medicine to stimulate appetite and gastric secretions
- Hops tea used for menstrual pain and as an emmenagogue in traditional European gynecology
- Topical use of hops poultices for neuralgia, rheumatic pain, and skin ulcers in folk medicine
- Native American groups (Iroquois, Cherokee) used related species Humulus americanus for pain and sleep
Modern Applications
- Sleep disorders: 2-methyl-3-buten-2-ol and other compounds show sedative effects; RCTs combining hops with valerian show significant improvement in sleep quality vs. placebo
- Anxiety reduction: GABA-A receptor modulation by hops compounds demonstrated in animal studies and supported by clinical trials
- Menopausal symptoms: 8-prenylnaringenin (8-PN) is the most potent plant phytoestrogen known; reduces hot flashes and insomnia in small RCTs
- Anti-cancer: xanthohumol inhibits multiple cancer cell lines and has anti-angiogenic properties in vitro and in animal models
- Antimicrobial: humulone and lupulone are potent against gram-positive bacteria (Staphylococcus, Clostridium) and Mycobacterium tuberculosis in vitro
- Anti-inflammatory: iso-alpha acids inhibit NF-ΞΊB and reduce COX-2 expression in macrophages
- Analgesic: alpha acids show opioid receptor-independent pain modulation in animal studies
- Metabolic: xanthohumol improves insulin sensitivity and lipid profiles in obese animal models
β οΈ Safety Information
Contraindications
- Pregnancy: phytoestrogenic and emmenagogue properties; avoid therapeutic doses
- Estrogen-sensitive conditions (ER+ breast cancer, uterine fibroids, endometriosis): 8-prenylnaringenin is strongly estrogenic
- Depression: sedative bitters may worsen depressive states; use with caution in major depression
- Pediatric use: avoid without professional supervision
- Pre-surgical anesthesia: CNS depressant effects are additive; discontinue 2 weeks prior to surgery
Side Effects
- Sedation and daytime drowsiness, especially when combined with alcohol or sedative medications
- Allergic contact dermatitis in hop pickers: 'hop picker's disease' from lupulin gland contact
- Mild GI upset (nausea, bitter taste) with high doses
- Hormonal effects in women: menstrual changes with chronic use of phytoestrogenic doses
- Exacerbation of depressive symptoms with long-term regular use
- Rare anaphylaxis in those with hop allergy
Drug Interactions
- CNS depressants (benzodiazepines, barbiturates, opioids, alcohol): significant additive sedation; risk of respiratory depression
- Antidepressants (SSRIs, MAOIs): potential interactions via serotonergic and MAO inhibitory activity of hops compounds
- Hormonal therapies (estrogen, tamoxifen, aromatase inhibitors): 8-prenylnaringenin may antagonize or augment estrogenic effects
- Sedative antihistamines (diphenhydramine, hydroxyzine): additive sedation
- CYP3A4 substrates: hops extract may inhibit CYP3A4 metabolism of multiple drugs
Parts Used
- Female strobiles (cones, primary)
- Lupulin glands (yellow resinous powder from strobiles)
- Whole dried strobiles
- Tincture and standardized extract
Preparation Methods
Dried strobile tea: 0.5β2 g in 250 ml boiling water, steep 10β15 minutes; 1β2 cups before bed for sleep
Standardized extract capsules: 60β500 mg/day (standardized to 0.5% 2-methyl-3-buten-2-ol equivalents)
Valerian-hops combination: most studied preparation; 160 mg hops + 480 mg valerian root extract per dose
Tincture (1:5 in 60% ethanol): 1β2 ml in 30 ml water, twice daily or before bed
Sleep pillow: 25β30 g dried hops stuffed in a small pillow; aromatherapeutic sedative via inhalation
Liquid extract (1:1): 0.5β2 ml before bedtime
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