Related Terms

• Acetylicariin, apigenin, baohuoside I, baohuoside II, barrenwort, benzene, Berberidaceae (family), breviflavone B, buxueyangyan mixture, caohuoside B, chrysoeriol, desmethylanhydroicaritin, desmethylicaritin, diphylloside B, Epimedii, Epimedii Herba, epimedin A, epimedin B, epimedin C, Epimedium acuminatum Franch., Epimedium brevicornum Maxim., Epimedium cremeum, Epimedium coactum, Epimedium davidii, Epimediumdiphyllum, Epimedium flavone, Epimedium grandiflorum Morr., Epimedium grandiflorum var. flavescens, Epimedium hunanense, Epimedium koreanum Nakai, Epimedium leptorrhizum, Epimedium pubescens Maxim., Epimedium sagittatum (Sieb. et Zucc.) Maxim., Epimedium sempervirens, Epimedium truncatum, Epimedium wushanense T.S. Ying, epimedokoreanoside-I, epimedoside A, epimedoside E, Herba Epimedii, huichun zhibao, hyperin, icariin, icarisid II, icaritin, ikarisoside A, ikarisoside C, ikarisoside F, Japanese epimedium, kaempferol, korepimedoside A, korepimedoside B linolenic acid, luteolin, magnoflorine, O-methylicariin, oleic acid, palmitic acid, prenyflavone, quercetin, sagittatoside A, sagittatoside B, sterols, syringaresinol, tannin, vitamin E, wanepimedoside A, xian ling pi, xin-qin granule (long-spur epimedium), yin yang huo, zuo-gui-wan.

Background

• The leaves of as many as 15 species of Epimedium are used as the herb known as yin yang huo in traditional Chinese medicine. "Yin yang huo" is usually translated as horny goat weed because the Chinese characters literally mean, "obscene goat leaves of pulse plants."

• In traditional Chinese medicine, Epimedium (yin yang huo) is used as a bodybuilding agent, a yang supporter, an agent to reinforce muscles and bones, and a supporter to the health of the liver and kidneys. This herb is also commonly used to treat angina pectoris (chest pain), chronic bronchitis, and neurasthenia (nervous exhaustion). As with many other herbs in Chinese medicine, horny goat weed is rarely used as a single ingredient. Horny goat weed is traditionally used as an ingredient in a yang tonic and for combating wind-damp-cold blocking qi circulation.

• Despite its traditional and popular use, there is little scientific evidence in support of horny goat weed. Currently, there exists a potential benefit for the treatment of atherosclerosis symptoms and quality of life associated with hemodialysis. Other promising areas include sexual function.

Scientific Evidence

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.

• Abortion, adrenal cortex function (atrophy), aging, allergy/hay fever, Alzheimer's disease, amenorrhea (absence of menstruation), analgesia, angina, antibacterial, anti-inflammatory, antimicrobial, antioxidant, antitussive (preventing or relieving cough), antiviral, aphrodisiac, asthma, cancer, chronic bronchitis, chronic hepatitis, cognitive improvement, cold prevention, coronary heart disease, erectile dysfunction, exercise performance enhancement, expectorant, fatigue, hepatoprotection, HIV/AIDS, hyperhomocysteinemia, hypercholesterolemia (high cholesterol), hypertension (high blood pressure), immunosuppression, impotence, infertility, kidney protection, leukopenia, memory, menopause, muscle ache, myocarditis/endocarditis, neurasthenia, osteoporosis, ovulation disorders, paralysis, platelet aggregation inhibition, prostate cancer, quality of life, renal failure (insufficiency), respiratory distress, thyroid disorders, tonic, viral infection (polio), yang insufficiency.

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 (over 18 years old)

• There is no proven safe or effective dose for horny goat weed. In general, 6-15 grams daily has been used. A decoction (5 grams of horny goat weed simmered in 250 milliliters of water for 10-15 minutes) three times daily has been used. A similar amount of horny goat weed in the form of granules (freeze-dried grains made from decocted herb), or powdered herb in capsules has been used. Also, 5 milliliters of 20% tincture three times daily before meals has been used.

• For angina pectoris, chronic bronchitis, and neurasthenia, 4-6 0.3-gram tablets (equivalent to 2.7 gram of raw material in each tablet), twice daily for one month have been used; administration has been stopped for 7-10 days and then resumed in a second series, if required.

• Intramuscular injections have also been used in ampoules of 2 milliliters (equivalent to 1 gram of raw material). Injections should only be given under the guidance of a qualified healthcare professional, including a pharmacist.

Children (under 18 years old)

• There is no proven safe or effective dose for horny goat weed in children, and use is not recommended.

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 in individuals with a known allergy or hypersensitivity to horny goat weed (Epimedium grandiflorum).

Side Effects and Warnings

• In general, horny goat weed is well tolerated. Based on long-term traditional use in Chinese culture, horny goat weed is possibly safe when taken by mouth at recommended doses. However, avoid use of horny goat weed in patients with fire from yin deficiency (people with too much "yang" or heat, masculinity, and activity, based on Chinese philosophy).

• Gastrointestinal complaints, such as nausea, vomiting and dryness of the mouth, are the most common side effects. Other side effects may include tachyarrhythmia (disturbance in the regular rhythm of the heartbeat), fever, or hypomania (a mild form of mania). Horny goat weed may also dilate coronary vessels and lower blood pressure. Long-term use may cause aggressiveness, irritability, or respiratory arrest. Extended use of Japanese Epimedium taken by mouth may result in nosebleed, exaggeration of tendon reflexes to the point of spasm, or dizziness. Certain compounds isolated from Epimedium davidii may affect immune responses in some individuals. Use cautiously in patients with immune function disorders due to the potential for worsening symptoms.

• Based on these side effects, horny goat weed is possibly unsafe when used in patients with tachyarrhythmia, decreased blood pressure, frequent nosebleeds, musculoskeletal disorders, bipolar disorder, immune function disorders, homocysteine disorders, thyroid disorders, respiratory distress, hormone-sensitive conditions, or cardiovascular disease.

Pregnancy & Breastfeeding

• Horny goat weed is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence. Horny goat weed may increase testosterone and estrogen levels in the body.

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

• Horny goat weed may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.

• Horny goat weed may lower cholesterol or blood pressure. Caution is advised in patients taking medications that also lower cholesterol or blood pressure. Consult with a qualified healthcare professional, including a pharmacist, before combining therapies.

• Horny goat weed have hormonal effects and may interact with certain medications, such as menopausal agents or birth control pills.

• Based on preliminary study, horny goat weed may also interact with immunostimulating, immunosuppressing or thyroid medications. Caution is advised.

• One species, Epimedium brevicorum, may inhibit the activity of monoamine oxidase in the hypothalamus. Caution is advised when taking horny goat weed with other monoamine oxidase inhibitors, such as MAOI antidepressants.

Interactions with Herbs & Dietary Supplements

• Horny goat weed may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking herbs or supplements that may increase the risk of bleeding. Dose adjustments may be necessary.

• Horny goat weed may lower cholesterol or blood pressure. Caution is advised in patients taking herbs and supplements that also lower cholesterol or blood pressure. Consult with a qualified healthcare professional, including a pharmacist, before combining therapies.

• Horny goat weed may have hormonal effects and may interact with certain herbs and supplements that also have hormonal effects, such as black cohosh or St. John's wort.

• Based on preliminary study, horny goat weed may also interact with immunostimulating, immunosuppressing or thyroid herbs and supplements. Caution is advised.

• One species, Epimedium brevicorum, may inhibit the activity of monoamine oxidase in the hypothalamus. Caution is advised when taking horny goat weed with other herbs and supplements with monoamine oxidase inhibitor activity.

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. Chen KM, Ge BF, Ma HP, et al. The serum of rats administered flavonoid extract from Epimedium sagittatum but not the extract itself enhances the development of rat calvarial osteoblast-like cells in vitro. Pharmazie 2004;59(1):61-64. View Abstract

2. De Naeyer A, Pocock V, Milligan S, et al. Estrogenic activity of a polyphenolic extract of the leaves of Epimedium brevicornum. Fitoterapia 2005;76(1):35-40. View Abstract

3. Lin CC, Ng LT, Hsu FF, et al. Cytotoxic effects of Coptis chinensis and Epimedium sagittatum extracts and their major constituents (berberine, coptisine and icariin) on hepatoma and leukaemia cell growth. Clin Exp.Pharmacol.Physiol 2004;31(1-2):65-69. View Abstract

4. Liu TZ, Chen CY, Yiin SJ, et al. Molecular mechanism of cell cycle blockage of hepatoma SK-Hep-1 cells by Epimedin C through suppression of mitogen-activated protein kinase activation and increased expression of CDK inhibitors p21(Cip1) and p27(Kip1). Food Chem Toxicol. 2006;44(2):227-235. View Abstract

5. Ma A, Qi S, Xu D, et al. Baohuoside-1, a novel immunosuppressive molecule, inhibits lymphocyte activation in vitro and in vivo. Transplantation 9-27-2004;78(6):831-838. View Abstract

6. Meng FH, Li YB, Xiong ZL, et al. Osteoblastic proliferative activity of Epimedium brevicornum Maxim. Phytomedicine. 2005;12(3):189-193. View Abstract

7. Oh MH, Houghton PJ, Whang WK, et al. Screening of Korean herbal medicines used to improve cognitive function for anti-cholinesterase activity. Phytomedicine. 2004;11(6):544-548. View Abstract

8. Partin JF, Pushkin YR. Tachyarrhythmia and hypomania with horny goat weed. Psychosomatics 2004;45(6):536-537. View Abstract

9. Sun Y, Fung KP, Leung PC, et al. Characterization of medicinal Epimedium species by 5S rRNA gene spacer sequencing. Planta Med 2004;70(3):287-288. View Abstract

10. Wang YK, Huang ZQ. Protective effects of icariin on human umbilical vein endothelial cell injury induced by H2O2 in vitro. Pharmacol.Res 2005;52(2):174-182. View Abstract

11. Wang ZQ, Lou YJ. Proliferation-stimulating effects of icaritin and desmethylicaritin in MCF-7 cells. Eur.J Pharmacol. 11-19-2004;504(3):147-153. View Abstract

12. Yap SP, Shen P, Butler MS, et al. New estrogenic prenylflavone from Epimedium brevicornum inhibits the growth of breast cancer cells. Planta Med 2005;71(2):114-119. View Abstract

13. Yin XX, Chen, ZQ, Dang GT, et al. [Effects of Epimedium pubescens icariine on proliferation and differentiation of human osteoblasts]. Zhongguo Zhong.Yao Za Zhi. 2005;30(4):289-291. View Abstract

14. Zhang CZ, Wang SX, Zhang Y, et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. J Ethnopharmacol. 4-26-2005;98(3):295-300. View Abstract

15. Zhang X, LiY, Yang X, et al. Inhibitory effect of Epimedium extract on S-adenosyl-L-homocysteine hydrolase and biomethylation. Life Sci 11-26-2005;78(2):180-186. View Abstract