enciclopedia naturale testata desktop
Humulus Lupulus
Natural Encyclopaedia


FAMILY: Cannabaceae. It has been known since ancient times for its soporific and calming effects. Workers in the old breweries, when processing hops, felt drowsy after a long time and had to stop work periodically to avoid falling asleep.

HABITAT: all of Europe and North America. Currently also cultivated in Australia and South America.

PUSED ART: inflorescences with a characteristic aromatic odour.

PHARMACEUTICAL PREPARATIONS: nebulised dry extract titrated in total flavonoids min. 4% and in essential oil min. 0.3% (French Pharmacopoeia X), whose daily dose ranges from 10 to 13 mg/kg, divided into two administrations, preferably between meals.

CHEMICAL COMPOSITION:  is a plant drug rich in flavonoids, such as astragaloside, xanthohumol min.0.2% and isoxanthohumol. It contains about 1% essential oil (min. 0.3%), consisting mainly of mono- and sesquiterpene carbons. The compounds responsible for the characteristic hop flavour are lupulone, umulone and derived compounds, the content of which ranges from 15 to 30%.

Action on the central nervous system. It has a sedative effect on the central nervous system, and is a good nervous balancer for various states of anxiety.
A controlled clinical trial investigated the effect on sleep of a valerian-luppol combination versus diphenhydramine and versus placebo. 184 patients at 9 sleep centres in the United States with moderate insomnia were enrolled. They received by mouth shortly before bedtime either 2 capsules of a product containing 187 mg dry extract of valerian and 42 mg dry extract of hops or 2 capsules of diphenhydramine (a chemical sleeping pill) of 25 mg each for 14 days followed by placebo for another 14 days or a placebo for 28 days. Sleep parameters were assessed by means of appropriate tests. With none of the treatments used were alterations noted in sleep stages 3 and 4 and in the REM phase of sleep itself. Quality of life was significantly better in the valerian-luppol group than in the diphenhydramine and placebo groups. No significant side effects were observed in any of the groups tested. The study indicates that the valerian-lupple combination is effective in promoting sleep and especially in improving quality of life in patients with moderate insomnia.

Action on the endocrine system. Hops contain substances with an action similar to that of oestrogen. The most important of these is 8-prenylnaringenin, which is a flavonoid.
A controlled clinical study examined the effect on neurovegetative disorders of the menopause of a hydroalcoholic extract of hops enriched with 8-prenylnaringenin, a phytoestrogen. Sixty-seven postmenopausal women were enrolled, taking either the extract or a placebo for three months. It was noted that there was a significant improvement in neurovegetative complaints of the menopause in both groups, but hop extract provided significantly better results than placebo after 6 weeks. The study indicates that hop extract containing 8-prenylnaringenin is more effective than placebo in alleviating the neurovegetative complaints of the menopause, particularly after 6 weeks of therapy.

SIDE EFFECTS: at high doses, stomach upset with nausea, dizziness, diarrhoeal phenomena and menstrual disorders in women may occur, albeit rarely.

CONTRAINDICATIONS: It should not be used if there are contraindications to the use of substances with oestrogenic action. It should not be used during pregnancy and lactation.



Leek M. et al. Effects of humulus lupulus extract on the central nervos system in mice. Planta Med. 59, suppl. 7/A 691, 1993
Kang Mee Lee j. Neuropharmacological activity of humulus lupulus extracts.  Korean J. Pharmacogn. 1
Roth R. Valerian and hop. Sedative agents with tradition. Therapiewoche 43, 1432-1438, 1993.
Fintelmann V. Clinical and medical significance of hop. Z. Phytother. 13, 165-168, 1992
Okamoto R. et al. Antigonadotropic activity of hop extract. Acta Endocrinol. 127, 371-377, 1992
Verschuere M. et al. Fractionation by SFE and microcolumn analysis of the essential oil and the bitter principles of the hop. J. Chromatogr. Sci. 30, 388-391, 1992
Meissner O. et al. Influence of Xanthohumol on the Binding Behavior of GABAA Receptors and their Lateral Mobility at Hippocampal Neurons. Planta Med. 2006 Jun;72(7):656-8, 2006.
Zanoli P. et al. Evidence that the beta-acids fraction of hops reduces central GABAergic neurotransmission. J Ethnopharmacol. 2006 Jul 11; [Epub ahead of print].
Zanoli P. et al. New insight in the neuropharmacological activity of Humulus lupulus L. J Ethnopharmacol. 2005 Jul 18; [Epub ahead of print].
Schiller H. et al. Sedating effects of Humulus lupulus L. extracts. Phytomedicine. 13(8):535-41, 2006.
Morin C.M. et al. Valerian-hops combination and diphenhydramine for treating insomnia: a randomised placebo-controlled clinical trial. Sleep. 2005 Nov 1;28(11):1465-71, 2005.
Possemiers S. et al. Activation of proestrogens from hops (Humulus lupulus L.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringenin. J. Agric. Food Chem. 53(16):6281-8, 2005.
Overk C.R. et al. Comparison of the in vitro oestrogenic activities of compounds from hops (Humulus lupulus) and red clover (Trifolium pratense). J. Agric. Food Chem. 53(16):6246-53, 2005.
Rimoldi G. et al. Morphologic changes induced by oral long-term treatment with 8-prenylnaringenin in the uterus, vagina, and mammary gland of castrated rats. Menopause. 13(4):669-77, 2006.
Heyerick A. et al. A first prospective, randomised, double-blind, placebo-controlled study on the use of a standardised hop extract to alleviate menopausal discomforts. Maturitas. 2005 Nov 28; [Epub ahead of print].
Nikolic D. et al. In vitro studies of intestinal permeability and hepatic and intestinal metabolism of 8-prenylnaringenin, a potent phytoestrogen from hops (Humulus lupulus L.). Pharm Res. 23(5):864-72, 2006.
Possemiers S. et al. The prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human Gut. J Nutr. 136(7):1862-7, 2006.
Rad M. et al. Pharmacokinetics and systemic endocrine effects of the phyto-oestrogen 8-prenylnaringenin after single oral doses to postmenopausal women. Br J Clin Pharmacol. 62(3):288-96, 2006.
Chadwick L.R. et al. The pharmacognosy of Humulus lupulus L. (hops) with an emphasis on estrogenic properties. Phytomedicine. 13(1-2):119-31, 2006.
Monteiro R. et al. Effect of hop (Humulus lupulus L.) flavonoids on aromatase (estrogen synthase) activity. J. Agric. Food Chem. 2006 Apr 19;54(8):2938-43, 2006.
Rimoldi G. et al. Morphologic changes induced by oral long-term treatment with 8-prenylnaringenin in the uterus, vagina, and mammary gland of castrated rats. Menopause. 13(4):669-77, 2006.
Nagasako-Akazome Y. et al. Safety evaluation of polyphenols extracted from hop bracts. Food Chem Toxicol. 2007 Feb 6; [Epub ahead of print].
Plazar J. et al. Protective effects of xanthohumol against the genotoxicity of benzo(a)pyrene (BaP), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and tert-butyl hydroperoxide (t-BOOH) in HepG2 human hepatoma cells. Mutat Res. 2007 May 21. [Epub ahead of print].
Possemiers S. et al. Eubacterium limosum activates isoxanthohumol from hops (Humulus lupulus L.) into the potent phytoestrogen 8-prenylnaringenin in vitro and in rat Gut. J Nutr. 138(7):1310-6, 2008.
Erkkola R. et al. A randomised, double-blind, placebo-controlled, cross-over pilot study on the use of a standardised hop extract to alleviate menopausal discomforts. Phytomedicine. 2010 Feb;16 [Epub ahead of print]
Cornu C. et al. A dietary supplement to improve the quality of sleep: a randomised placebo controlled trial. BMC Complement Altern Med. 2010 Jun 22;10(1):29. [Epub ahead of print]
Di Viesta V. et al. Increased sexual motivation in female rats treated with Humulus lupulus L. extract. J Ethnopharmacol. 134(2):514-7, 2011.
Yen T.L. et al. Neuroprotective Effects of Xanthohumol, a Prenylated Flavonoid from Hops (Humulus lupulus), in Ischemic Stroke of Rats. J. Agric. Food Chem. 2012 Feb 29;60(8):1937-44, 2012.
Ming L.G. et al. The prenyl group contributes to activities of phytoestrogen 8-prenynaringenin in enhancing bone formation and inhibiting bone resorption in vitro. Endocrinology. 154(3):1202-14. doi: 10.1210; EN 2012-2086, 2013:
Hajirahimkhan A. et al. Evaluation of estrogenic activity of licorice species in comparison with Hops used in botanicals for menopausal symptoms. PLoS One. 8(7):e67947. doi: 10.1371/journal.pone.0067947. Print 2013.
Yuan Y. et al. Inhibition of human cytochrome P450 enzymes by hops (Humulus lupulus) and hop prenylphenols. Eur J Pharm Sci. 2013 Dec 14;53C:55-61. doi: 10.1016/j.ejps.2013.12.003. [Epub ahead of print]
Helle J. Et al. Assessment of the proliferative capacity of the flavanones 8-prenylnaringenin, 6-(1.1-dimethylallyl)naringenin and naringenin in MCF-7 cells and the rat mammary gland. Mol Cell Endocrinol. 392(1-2):125-35. doi: 10.1016/j.mce.2014.05.014, 2014
Yao Y. et al. Xanthohumol, a polyphenol chalcone present in hops, activating Nrf2 enzymes to confer protection against oxidative damage in PC12 cells. J. Agric. Food Chem. 2015 Feb 11;63(5):1521-31. doi: 10.1021/jf505075n, 2015.
Aghamiri V. et al. The effect of Hop (Humulus lupulus L.) on early menopausal symptoms and hot flashes: A randomized placebo-controlled trial. Complement Ther Clin Pract.  pii: S1744-3881(15)00039-0. doi: 10.1016/j.ctcp.2015.05.001, 2015.
Abdi F. et al. Protocol for systematic review and meta-analysis: hop (Humulus lupulus L.) for menopausal vasomotor symptoms. BMJ Open file. 6(4):e010734. doi: 10.1136/bmjopen-2015-010734, 2016.