Hops (Humulus lupulus) is a native British plant with a stout root, heart-shaped leaves and cone-like flowers. Romans ate the young shoots in the spring in the same way we do asparagus. Hops was first used by breweries in the Netherlands in the early fourteenth century. Hops has been used traditionally for nervous disorders.

Hops benefits
Hops is useful as a sleep inducer, has antioxidant activity, anti-inflammatory, estrogen-like properties, and potential anti-tumor activity. Furthermore, compounds in hops may reduce insulin resistance. Additional nutrients helpful for sleep include melatonin, passion flower, chamomile.

Hops overview
Hops is a climbing perennial herb with male and female flowers on separate plants, native to Europe, Asia, and North America, extending roughly from 35 to 55 degrees north latitude, extensively cultivated in temperate zones worldwide. The material of commerce comes exclusively from female plants cultivated primarily in the United States, Germany, Great Britain, the Czech Republic, and China (BHP, 1990; Bruneton, 1995; DeLyser and Kasper, 1994; Leung and Foster, 1996; Wichtl and Bisset, 1994). The origin of hop cultivation is poorly documented, though it is first reported ca. 860 C.E. In the 1860s Germans brought hop cultivation to China and Korea, and to Japan in 1876, where German and American cultivars were used instead of the native Japanese variety (DeLyser and Kasper, 1994). Its common name is derived from the Anglo-Saxon hoppan (to climb). According to Pliny the Elder (ca. 23–79 C.E.), its species name lupulus is derived from Latin lupus (wolf), because when it grows among osiers (willows), it strangles them by its light, climbing embraces, as a wolf does a sheep (Grieve, 1979).

The therapeutic use of hops in Europe dates back to at least the ninth century. Before that it was used in making beers and breads, and also as a salad vegetable (DeLyser and Kasper, 1994). In North American aboriginal medicines, the Cherokee used hops as a sedative, antirheumatic, analgesic, gynecological aid for breast and womb problems, and kidney and urinary aid for "gravel" and inflamed kidneys (Hamel and Chiltoskey, 1975). In India, the Ayurvedic Pharmacopoeia recommends hops for restlessness associated with nervous tension, headache, and indigestion; and reports its actions as sedative, hypnotic, and antibacterial (Karnick, 1994). In traditional Chinese medicine, it is used to treat insomnia, restlessness, dyspepsia, intestinal cramps, and lack of appetite. In China, the ethanol fluidextract dosage form is the most commonly used preparation (Chang and But, 1986; Leung and Foster, 1996).

In Germany, hops is licensed as a standard medicinal tea, and about 70 prepared sedative medicines contain hops extract. In Germany and the United States, hops infusions, tinctures, and dry extracts are used in sedative preparations for anxiety and unrest (Leung and Foster, 1996; Wichtl and Bisset, 1994). Hop strobile and hops extract were listed in the United States National Formulary (NF) and unofficial in the United States Pharmacopoeia (USP) from 1831 to 1910 (Boyle, 1991).

Human studies generally investigate use of hops in combination with other herbs (e.g., valerian root). One study examined the effects of the drug Seda-Kneipp N, which contains dry extracts of hop strobile (9.0–11.0:1) and valerian root (5.5–74:1), on patients suffering from sleep disorders. The study reported that hops lessened sleep disturbances when given in combination with valerian (Kneipp , 1996; M ller-Limmroth and Ehrenstein, 1977; Newall et al., 1996). However, it is not possible to determine if the action is caused by the hops, the valerian, or a possible synergy between the two.

One randomized, double-blind, controlled clinical trial in a parallel group design assessed quality of life parameters of patients with exogenous sleep disorders, such as temporary sleep onset and sleep interruption, treated with a hops-valerian preparation or a benzodiazepine drug. This trial demonstrated equivalent efficacy and tolerability according to DSM-IV criteria. The equivalence of both therapies according to sleep quality, fitness, and quality of life was demonstrated. The patients' state of health improved during therapy and then deteriorated after cessation with both preparations. The authors concluded that the investigated hop-valerian preparation in the appropriate dose is a sensible alternative to benzodiazepine for the treatment of nonchronic and non-psychiatric sleep disorders (Schmitz and Jackel, 1998).

Clinical studies conducted in China have investigated and reported positive outcomes for the use of hops preparations in the treatment of tuberculosis, leprosy, acute bacillary dysentery, silicosis, and asbestosis (Chang and But, 1986).

Though the sedative effect of hops is indisputable, its mechanism of action is not yet understood (Bradley, 1992). The approved modern therapeutic applications for hops are supportable based on its long history of use in well established systems of traditional medicine, documented pharmacological actions reported in in vitro and in vivo studies in animals, and human clinical studies.

European pharmacopeial grade hops must contain not less than 18% water soluble extractive and not less than 25% water and methanol soluble extractive. It must pass an assay that includes thin-layer chromatography (TLC) analysis of the flavonoids. Additionally, the German Standard License for hops medicinal tea requires the raw material to contain at least 0.5% flavonoids, calculated as rutin (BHP, 1996; Bradley, 1992; Braun et al., 1997; Bruneton, 1995; DAB, 1997; Wichtl and Bisset, 1994). The Ayurvedic Pharmacopoeia requires not less than 13% water soluble extractive (Karnick, 1994).

Description

Hops, consisting of the dried strobiles of Humulus lupulus L. [Fam. Cannabaceae], and their preparations in effective dosage. The preparation contains at least 0.35 % (v/w) essential oil. Other ingredients are a- and b-bitter acids and 2-methyl-3-butanol.

Chemistry and Pharmacology
Hop strobile contains resinous bitter principles (5–30%), mostly a-bitter acids (humulones 2–10%) and b-bitter acids (lupulones 2–16%) and their oxidative degradation products (2-methyl-3-buten-2-ol); polyphenolic condensed tannins (2–4%); volatile oil (0.35–1.0%), mainly monoterpenes and sesquiterpenes (b-caryophyllene, farnesene, humulene, b-myrcene); chalcones (xanthohumol); flavonoids (kaempferol, quercetin, rutin); phenolic acids; and amino acids (Bradley, 1992; Bruneton, 1995; ESCOP, 1997; Leung and Foster, 1996; Newall et al., 1996; Wichtl and Bisset, 1994). Unpublished analysis on some hops varieties by a major hops producer indicates the following ranges for some key components: resinous bitter principles (5–30%), humulones (2–18%), and volatile oil (0.5–3.0%) (Kostelecky, 1999).

The Commission E reported calming and sleep-promoting activity.

The British Herbal Compendium reported its actions as sedative, soporific, spasmolytic and aromatic bitter (Bradley, 1992). Hops are generally combined with other sedative herbs and have been reported to improve sleep when taken with valerian (M ller-Limmroth and Ehrenstein, 1977; Newall et al., 1996).

Uses
The Commission E approved the internal use of hops for mood disturbances such as restlessness and anxiety as well as sleep disturbances.

The British Herbal Compendium indicated its use for excitability, restlessness, disorders of sleep, and lack of appetite (Bradley, 1992). ESCOP indicates its use for tenseness, restlessness, and difficulty in falling asleep (ESCOP, 1997). The German Standard License for hops tea infusion indicates its use for disturbed states such as restlessness and disorders of sleep (Braun et al., 1997).

Contraindications
None known.

Side Effects
None known.

Use During Pregnancy and Lactation
No restrictions known.

Interactions with Other Drugs
None known.

Dosage and Administration
Unless otherwise prescribed: Single dosage of 0.5 g cut or powdered strobile or dry extract powder for infusions, decoctions, or other preparations. Liquid and solid preparations for internal use. Note: Combinations with all other sedatives can be beneficial.
Infusion or decoction: 0.5 g in 150 ml water.
Fluidextract 1:1 (g/ml): 0.5 ml.
Tincture 1:5 (g/ml): 2.5 ml.
Native dry extract 6–8:1 (w/w): 0.06–0.08 g (60–80 mg).

References
Boyle, W. 1991. Official Herbs: Botanical Substances in the United States Pharmacopoeias 1820–1990. East Palestine, OH: Buckeye Naturopathic Press.
Bradley, P.R. (ed.). 1992. British Herbal Compendium, Vol. 1. Bournemouth: British Herbal Medicine Association.
Braun, R. et al. 1997. Standardzulassungen f r Fertigarzneimittel—Text and Kommentar. Stuttgart: Deutscher Apotheker Verlag.
British Herbal Pharmacopoeia (BHP). 1990. Bournemouth, U.K.: British Herbal Medicine Association.
———. 1996. Exeter, U.K.: British Herbal Medicine Association.
Bruneton, J. 1995. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris: Lavoisier Publishing.
Chang, H.M. and P.P.H. But. 1986. Pharmacology and Applications of Chinese Materia Medica. Philadelphia: World Scientific. 1077–1083.
Deutsches Arzneibuch (DAB 1997). 1997. Stuttgart: Deutscher Apotheker Verlag.
DeLyser, D.Y. and W.J. Kasper. 1994. Hopped Beer: The Case for Cultivation. Economic Botany 48(2):166–170.
ESCOP. 1997. "Lupuli strobulus." Monographs on the Medicinal Uses of Plant Drugs. Exeter, U.K.: European Scientific Cooperative on Phytotherapy.
Grieve, M. 1979. A Modern Herbal. New York: Dover Publications, Inc.
Hamel, P.B. and M.U. Chiltoskey. 1975. Cherokee Plants and Their Uses—A 400-Year History. Sylva, N.C.: Herald Publishing Co.
Karnick, C.R. 1994. Pharmacopoeial Standards of Herbal Plants, Vols. 1–2. Delhi: Sri Satguru Publications. Vol. 1:183–184, Vol. 2:67.
Kneipp .1996. Wegweiser zu den Kneipp Mitteln [Guide to Kneipp Remedies]. W rzburg: Sebastian Kneipp Gesundheitsmittel-Verlag. 88–89.
Kostelecky, T. 1999. (John I. HAAS, Inc.). Personal communication to A. Goldberg, May 26.
Leung, A.Y. and S. Foster. 1996. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2nd ed. New York: John Wiley & Sons, Inc.
M ller-Limmroth, W. and W. Ehrenstein. 1977. Untersuchungen ber die Wirkung von Seda-Kneipp auf den Schlaf schlafgestrˆrter Menschen [Experimental studies of the effects of Seda-Kneipp on the sleep of sleep disturbed subjects; implications for the treatment of different sleep disturbances]. Med Klin 72(25):1119–1125.
Newall, C.A., L.A. Anderson, J.D. Phillipson. 1996. Herbal Medicines: A Guide for Health-Care Professionals. London: The Pharmaceutical Press.
Schmitz, M. and M. Jackel. 1998. Vergleichsstudie zur Untersuchung der Lebensqualitat von Patienten mit exogenen Schlafstorungen (vor bergehenden Ein- und Durchschlafstorungen) unter Therapie mit einem Hopfen-Baldrian-Pr‰parat und einem Benzodiazepin-Pr‰parat [Comparative study for assessing quality of life of patients with exogenous sleep disorders (temporary sleep onset and sleep interruption disorders) treated with a hops-valerian preparation and a benzodiazepine drug]. Wien Med Wochenschr 148(13):291–298.
Wichtl, M. and N.G. Bisset (eds.). 1994. Herbal Drugs and Phytopharmaceuticals. Stuttgart: Medpharm Scientific Publishers.

Additional Resources
Bown, D. 1995. Encyclopedia of Herbs and Their Uses. New York: DK Publishing, Inc. 294.
British Pharmaceutical Codex (BPC). 1949. London: The Pharmaceutical Press.
Bravo, L., J. Cabo, A. Fraile, J. Jimenez, A. Villar. 1974. Estudio Farmacodinamico del Lupulo (Humulus lupulus L.). Accion Tranquilizante. Boll Chim Farm 113:310–315.
Caujolle, F., P.H. Chanh, P. Duch-Kan, L. Bravo-Diaz. 1969. Etude de l'action spasmolytique du houblon (Humulus lupulus, CannabinacÈes) [Spasmolytic action of hop]. Agressologie 10(5):405–410.
Council of Europe. 1981. Flavouring Substances and Natural Sources of Flavourings, 3rd ed. Strasbourg: Maisonneuve.
Der Marderosian, A. (ed.). 1999. The Review of Natural Products. St. Louis: Facts and Comparisons.
Duke, J.A. 1985. Handbook of Medicinal Herbs. Boca Raton: CRC Press.
H‰nsel, R. and H.H. Wagener. 1967. Versuche, sedativ-hypnotische Wirkstoffe im Hopfen nachzuweisen [Attempts to identify sedative-hypnotic active substances in hops]. Arzneimforsch 17(1):79–81.
H‰nsel, R., R. Wohlfart, H. Coper. 1980. Narcotic action of 2-methyl-3-butene-2-ol contained in the exhalation of hops [in German]. Z Naturforsch 35(1112):1096–1097.
H‰nsel, R., R. Wohlfart, H. Schmidt. 1982. The sedative-hypnotic principle of hops. 3. Communication: Contents of 2-methyl-3-butene-2-ol in hops and hop preparations. Planta Med 45:224–228.
H‰nsel, R. and J. Schulz. 1986. Hopfen und Hopfenpr‰parate: Fragen zur pharmazeutischen Qualit‰t. Dtsch Apoth Ztg 126:2033–2037.
———. 1986. Hopfenzapfen (Lupuli strobulus): D nnschichtchromatographische Pr fung auf Identit‰t. Dtsch Apoth Ztg 126:2347–2648.
H‰nsel, R. 1995. Pflanzliche Beruhigungsmittel. Mˆglichkeiten und Grenzen in der Selbstmedikation. Dtsch Apoth Ztg 135:2935–2943.
Karrer, W. 1958. Konstitution und Vorkommen der Organischen Pflanzenstoffe (exclusive Alkaloide). Basel: Birkh‰user Verlag.
List, P.H. and L. Hˆrhammer (eds.). 1973–1979. Hagers Handbuch der Pharmazeutischen Praxis, Vols. 1–7. New York: Springer Verlag.
McGuffin, M., C. Hobbs, R. Upton, A. Goldberg. 1997. American Herbal Product Association's Botanical Safety Handbook. Boca Raton: CRC Press.
PharmacopÈe FranÁaise Xe …dition (Ph.Fr.X.). 1983–1990. Moulins-les-Metz: Maisonneuve S.A.
Reynolds, J.E.F. (ed.). 1982. Martindale: The Extra Pharmacopoeia, 28th ed. London: The Pharmaceutical Press.
Wichtl, M. 1988. In: Braun, R. (ed.). Standardzulassung f r Fertigarzneimittel—Text und Kommentar. Stuttgart: Deutsche Apotheker Verlag.
Wichtl, M. 1989. In: Wichtl, M. (ed.). Teedrogen, 2nd ed. Stuttgart: Wissenschaftliche Verlagsgesellschaft. 242–245.
Wohlfart, R. 1993. In: H‰nsel, R., K. Keller, H. Rimpler, G. Schneider (eds.). 1993. Hagers Handbuch der Pharmazeutischen Praxis, 5th ed. Vol. 5. Drogen E-O. Berlin-Heidelberg: Springer Verlag. 447–458.

Note
This material was adapted from The Complete German Commission E Monographs—Therapeutic Guide to Herbal Medicines. M. Blumenthal, W.R. Busse, A. Goldberg, J. Gruenwald, T. Hall, C.W. Riggins, R.S. Rister (eds.) S. Klein and R.S. Rister (trans.). 1998. Austin: American Botanical Council; Boston: Integrative Medicine Communications.
1) The Overview section is new information.
2) Description, Chemistry and Pharmacology, Uses, Contraindications, Side Effects, Interactions with Other Drugs, and Dosage sections have been drawn from the original work. Additional information has been added in some or all of these sections, as noted with references.
3) The dosage for equivalent preparations (tea infusion, fluidextract, and tincture) have been provided based on the following example:
Unless otherwise prescribed: 2 g per day of [powdered, crushed, cut or whole] [plant part]
Infusion: 2 g in 150 ml of water
Fluidextract 1:1 (g/ml): 2 ml
Tincture 1:5 (g/ml): 10 ml
4) The References and Additional Resources sections are new sections. Additional Resources are not cited in the monograph but are included for research purposes.

Excerpt from Herbal Medicine:
Expanded Commission E Monographs
Copyright 2000 American Botanical Council
Published by Integrative Medicine Communications
Available from the American Botanical Council.

This material is not intended as a guide to self medication by consumers. The lay reader is advised to discuss the information contained herein with a doctor, pharmacist, nurse or other authorized health care practitioner. Neither the editors nor the publisher accepts any responsibility for the accuracy of the information itself or the consequences from the use or misuse of the information contained herein.