DRUGS AND SUPPLEMENTS

Hops (Humulus lupulus L.)

March 22, 2017

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Hops (Humulus lupulus)

Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

  • 6-Prenylnaringenin (6-PN), 8-prenylnaringenin (8-PN), adenylate isopentenyltransferase, alpha-acids, beta-acids, bitter acids, Cannabaceae (family), catechin, chalcones, cohulupone, colupulone, common hops, Elusan®, epicatechin, European hops, geranyl(geranyl)diphosphate synthase, hop, hop strobile, Hopfen (German), houblon (French), hulupinic acid, humulon, humulus, Humulus lupulus, iso-alpha-acids, isoxanthohumol (IXN), kaempferol glycosides, kaempferol-7-O-rutinoside, Lupuli strobulus, lupulin, lupulus, myrcene, oxidized cohumulinone, oxidized hop alfa-bitter acids, oxidized humulinone derivatives, prenylated 2`-hydroxychalcones, prenylflavonoids, procyanidin dimer B, quercetin, rutin, silicon, spent hops, volatile thiols, xanthohumol (XN), Ze 91019.

Background

  • Hops are the seed cones from the Humulus lupulus plant. H. lupulus belongs to the family Cannabaceae and is native to Europe, Asia, and North America. Hops are cultivated primarily in the United States, Germany, Great Britain, the Czech Republic, and China.

  • Hops are widely used to preserve beer and give it its characteristic aroma and flavor. Essential oils of hops are used in perfumes, cereals, beverages, and tobacco.

  • Traditionally, hop preparations have been used for relaxation, anxiety, and sedation, and to treat sleep disorders. There has been limited research evaluating the effects of hops on sleep.

  • Hops may have effects on hormone-sensitive conditions, such as breast cancer, uterine cancer, cervical cancer, prostate cancer, or endometriosis. The exact effects of hops on these conditions are unclear.

Scientific Evidence

Uses

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Grade*

Antioxidant

Limited evidence suggests that hop extract may decrease oxidative stress and markers of cardiovascular risk and inflammation. Further research is needed in this area before a conclusion can be made.

C

Asthma

Limited evidence suggests that hop extract may improve quality of life in adults with asthma but may not affect pulmonary function. Further research is needed in this area before a conclusion can be made.

C

Cardiovascular risk reduction

Limited evidence suggests that hop extract may decrease oxidative stress and markers of cardiovascular risk and inflammation. Further research is needed in this area before a conclusion can be made.

C

Chronic venous insufficiency (phlebostatic ulcer)

Limited evidence suggests that Idrastin®, a combination product containing hops, may be useful, in addition to elastocompressive therapy, for the treatment of phlebostatic sores. Further research is needed in this area before a conclusion can be made.

C

Deodorant

Limited evidence suggests that a topical underarm combination treatment of hop extract and zinc ricinoleate may have odor reduction and antibacterial effects. Further research using hops alone as a treatment is needed.

C

Insomnia/sleep quality

Preliminary studies report that hops may have sedative and sleep-enhancing effects. However, little research has evaluated the effects of hops on sleep quality in humans. Further research is needed in this area before a conclusion can be made.

C

Menopausal symptoms

When used in combination with other products, hops may help alleviate menopausal symptoms, such as hot flashes and difficulty sleeping, because it has estrogen-like activity. However, until more well-designed studies are performed, a firm conclusion cannot be made.

C

Metabolic syndrome

Some evidence suggests that hops in combination with other agents may be effective for metabolic syndrome. Further research is needed to determine the effects of hops alone.

C

Rheumatic diseases

Early clinical research suggests that a combination formula containing hops may help reduce symptoms of rheumatic diseases, such as osteoarthritis, rheumatoid arthritis, and fibromyalgia. However, well-designed human trials using hops alone are needed to determine if these positive effects are specifically the result of hops.

C

Sedation (reduced alertness)

Hops have been used traditionally as a sedative, for relaxation and reduction of anxiety. Although some preliminary studies suggest possible sedative properties, there is limited research in this area. Better studies are needed before a firm conclusion can be made.

C

*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).

Tradition/Theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.

  • Analgesic, antibacterial, antifungal, anti-inflammatory, antimicrobial, antispasmodic, antiviral (anti-HCV, antirhinovirus, antiherpesvirus), anxiety, aphrodisiac (promotes sexual desire), appetite stimulant, asbestosis, atherosclerosis (hardening of the arteries), atopic dermatitis, breast cancer, breast enlargement, cancer, colds/flu, Crohn's disease, diabetes, digestion, diuretic (increases urination), dysentery (severe diarrhea), dyspepsia (indigestion), earaches, Epstein-Barr virus, estrogenic effects, gynecologic disorders (female reproductive disorders), hyperlipidemia (high blood lipids), irritable bowel syndrome (IBS), kidney disorders, leprosy, leukemia (HL-60), mood disturbances, muscle spasm, nervous disorders, obesity, osteoporosis, parasitic infections, restlessness, scoliosis (curvature of the spine), seizures, skin ulcers (topical), toothache, tuberculosis, wound healing.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

  • As an antioxidant, 400 milligrams of commercial hops (Elusan®) has been taken by mouth daily for 30 days.

  • For cardiovascular risk reduction, 400 milligrams of commercial hops (Elusan®) has been taken by mouth daily for 30 days.

  • For insomnia or sleep disturbances, capsules containing 250 milligrams of lupulin (a glandular powder separated from part of the hop plant) has been taken by mouth for five days. Traditionally, doses of 0.5-1.0 gram of dried hops extract or 0.5-1.0 milliliter of liquid hops extract (1:1 in 45% alcohol) have been taken by mouth up to three times daily. A dose of 300-400 milligrams of hops extract combined with 240-300 milligrams of valerian (Valeriana officinalis) extract has been taken by mouth before bed.

  • For menopausal symptoms, 100 or 250 micrograms of a hop extract standardized to 8-prenylnaringenin (the phytoestrogen in hops) has been taken by mouth for 8-12 weeks.

  • Intravenous or intramuscular dosing is not recommended.

Children (younger than 18 years)

  • Hops extract is traditionally considered to be one of the milder sedative herbs and to be safe for children. However, there is limited research in this area and safety and effectiveness has not been clearly established.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

  • Avoid with known allergy or hypersensitivity to hops, its constituents, or other members of the Cannabaceae family. Contact dermatitis from hops has been reported. Allergy to hop pollen has been reported anecdotally. Bronchial hyperresponsiveness has also been reported. Hay fever or asthma may be the result of hop allergy.

  • Avoid in those with allergy to peanuts, chestnuts, and bananas, as they may also be allergic to hops.

Side Effects and Warnings

  • Hops may cause increased gastric acid, increased risk of central nervous system (CNS) depression, vomiting, abdominal pain, hyperthermia (elevated body temperature), restlessness, panting, seizures, chronic respiratory symptoms (dry cough, dyspnea (difficulty breathing), chronic bronchitis) and other occupational respiratory diseases, dizziness, reduced activity and alertness, and slowing of thought processes.

  • Use cautiously in combination with CNS depressants, sedatives, or antipsychotics. Drowsiness or sedation may occur. Use caution if driving or operating heavy machinery.

  • Use cautiously if pregnant or breastfeeding, due to possible hormonal (estrogenic) and sedative effects of hops or other ingredients found in combination products. Some hop preparations contain high levels of alcohol and should be avoided during pregnancy.

  • Use cautiously in patients with hormone-sensitive conditions (e.g., breast cancer, uterine cancer, cervical cancer, prostate cancer, or endometriosis) or in those taking hormonal agents (e.g., contraceptives or fertility agents). Because hops contain estrogen-like chemicals, the effects of other agents believed to have estrogen-like properties may be altered.

  • Use cautiously in patients with autoimmune disorders or those using immunosuppressant agents, as constituents of hops may alter the immune system.

  • Hops may lower blood sugar levels in normal individuals but may increase blood sugar in those with diabetes. Caution is advised in patients with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Blood sugar levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.

  • Hops may interfere with the way the body processes certain drugs, herbs, or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of these agents may change in the blood and may cause increased or decreased effects or potentially serious adverse reactions. Patients taking any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.

  • Avoid with known allergy or hypersensitivity to hops, its constituents, or other members of the Cannabaceae family. Contact dermatitis from hops has been reported. Bronchial hyperresponsiveness has also been reported. Hay fever or asthma may be the result of hop allergy.

  • Avoid in those with allergy to peanuts, chestnuts, and bananas, as they may also be allergic to hops.

Pregnancy and Breastfeeding

  • Hops are not recommended during pregnancy or lactation, due to possible hormonal and sedative effects. Many tinctures contain high levels of alcohol and should be avoided during pregnancy.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

  • Hops may lower blood sugar levels in normal individuals but may increase blood sugar in those with diabetes. Caution is advised in patients with diabetes or hypoglycemia, and in those taking antidiabetic agents or drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.

  • Hops may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be altered in the blood and may cause increased or decreased effects, or potentially serious adverse reactions. Patients using any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.

  • Hops may increase the amount of drowsiness caused by some drugs. Examples include benzodiazepines such as lorazepam (Ativan®) or diazepam (Valium®), barbiturates such as phenobarbital, narcotics such as codeine, some antidepressants, and alcohol. Caution is advised while driving or operating machinery.

  • Hops may also interact with acetaminophen, agents that affect the immune system, antibiotics, antifungals, anti-inflammatory agents (such as celecoxib), anticancer drugs, antipsychotic agents, antiulcer agents, birth control pills, central nervous system (CNS) depressants, disulfiram (Antabuse®), fertility agents, hormonal agents (such as tamoxifen or raloxifene), interferons, lipid-lowering agents, metronidazole (Flagyl®), painkillers (such as Idrastin®), and steroids.

Interactions with Herbs and Dietary Supplements

  • Hops may lower blood sugar levels in normal individuals but may increase blood sugar in those with diabetes. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood sugar levels may require monitoring, and doses may need adjustment.

  • Hops may interfere with the way the body processes certain herbs or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of other herbs or supplements may become too high or too low in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.

  • Hops may increase the amount of drowsiness caused by some herbs or supplements such as some antidepressants.

  • Because hops contain estrogen-like chemicals, the effects of other agents believed to have estrogen-like properties may be altered.

  • Hops may also interact with antibacterials, anticancer agents, antifungals, anti-inflammatory agents, antioxidants, antipsychotic agents, antiulcer agents, antivirals, birth control agents, central nervous system (CNS) depressants, fertility agents, herbs and supplements that affect the immune system, herbs and supplements that promote sexual desire, hormonal agents, lipid-lowering agents, pain-relieving herbs and supplements, steroids, and valerian.

Author Information

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  1. Chadwick LR, Nikolic D, Burdette JE, et al. Estrogens and congeners from spent hops (Humulus lupulus). J Nat Prod 2004;67(12):2024-32. View Abstract

  2. 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(6):389-396. View Abstract

  3. Estrada JL, Gozalo F, Cecchini C, et al. Contact urticaria from hops (Humulus lupulus) in a patient with previous urticaria-angioedema from peanut, chestnut and banana. Contact Dermatitis 2002;46(2):127. View Abstract

  4. Foster BC, Arnason JT, Saleem A, et al. Comparative study of hops-containing products on human cytochrome P450-mediated metabolism. J Agric Food Chem 2011;59(9):5159-5163. View Abstract

  5. 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(2):164-75. View Abstract

  6. Lopez-Jaen AB, Codoñer-Franch P, Martínez-Álvarez JR, et al. Effect on health of non-alcohol beer and hop supplementation in a group of nuns in a closed order. Proceedings of the Nutrition Society 2010;69(OCE3):26.

  7. Lukaczer D, Darland G, Tripp M, et al. A pilot trial evaluating Meta050, a proprietary combination of reduced iso-alpha acids, rosemary extract and oleanolic acid in patients with arthritis and fibromyalgia. Phytother Res 2005;19(10):864-9. View Abstract

  8. Morali G, Polatti F, Metelitsa EN, et al. Open, non-controlled clinical studies to assess the efficacy and safety of a medical device in form of gel topically and intravaginally used in postmenopausal women with genital atrophy. Arzneimittelforschung 2006;56(3):230-8. View Abstract

  9. Morin CM, Koetter U, Bastien C, et al. Valerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trial. Sleep 2005;28(11):1465-71. View Abstract

  10. Possemiers S, Bolca S, Grootaert C, et al. The prenylflavonoid isoxanthohumol from hops (Humulus lupulus L.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestine. J Nutr 2006;136(7):1862-7. View Abstract

  11. Schellenberg R, Sauer S, Abourashed EA, et al. The fixed combination of valerian and hops (Ze91019) acts via a central adenosine mechanism. Planta Med 2004;70(7):594-7. View Abstract

  12. Stevens JF, Page JE. Xanthohumol and related prenylflavonoids from hops and beer: to your good health! Phytochemistry 2004;65(10):1317-30. View Abstract

  13. Sun J. Morning/evening menopausal formula relieves menopausal symptoms: a pilot study. J Altern Complement Med 2003;9(3):403-9. View Abstract

  14. Wang YJ, Dou J, Cross KP,et al. Computational analysis for hepatic safety signals of constituents present in botanical extracts widely used by women in the United States for treatment of menopausal symptoms. Regul Toxicol Pharmacol 2011;59(1):111-124. View Abstract

  15. Yajima H, Ikeshima E, Shiraki M, et al. Isohumulones, bitter acids derived from hops, activate both peroxisome proliferator-activated receptor alpha and gamma and reduce insulin resistance. J Biol Chem 2004;279(32):33456-62. View Abstract

Copyright © 2013 Natural Standard (www.naturalstandard.com)

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

Updated:  

March 22, 2017