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URL of this page: https://medlineplus.gov/druginfo/natural/699.html

Horny Goat Weed

What is it?

Horny goat weed refers to various herb species of the Epimedium genus, and may be known as "yin yang huo." It has limited evidence of health benefits.

Horny goat weed contains chemicals that might help increase blood flow and improve sexual function. It also contains phytoestrogens, chemicals that act somewhat like the hormone estrogen.

People use horny goat weed for erectile dysfunction (ED), sexual problems, weak and brittle bones, health problems after menopause, and other conditions, but there is no good scientific evidence to support any of these uses.

How effective is it?

There is interest in using horny goat weed for a number of purposes, but there isn't enough reliable information to say whether it might be helpful.

Is it safe?

When taken by mouth: Horny goat weed extract is possibly safe when used short-term. A specific extract of horny goat weed containing phytoestrogens has been taken by mouth safely for up to 2 years. Another extract containing a chemical called icariin has been taken safely for up to 6 months.

But some types of horny goat weed are possibly unsafe when used for a long period of time or in high doses. Serious side effects including severe breathing problems have been reported.

Special precautions & warnings:

Pregnancy: Horny goat weed is possibly unsafe when taken by mouth during pregnancy. It might harm the developing fetus. Avoid using it.

Breast-feeding: There isn't enough reliable information to know if horny goat weed is safe to use when breast-feeding. Stay on the safe side and avoid use.

Bleeding disorders: Horny goat weed might slow blood clotting. This might increase the risk of bleeding. Taking horny goat weed might make bleeding disorders worse.

Hormone sensitive cancers and conditions: Horny goat weed acts like estrogen and can increase estrogen levels in some people. Horny goat weed might worsen some estrogen-sensitive conditions, such as breast and uterine cancer.

Surgery: Horny goat weed might slow blood clotting. This might increase the risk of bleeding during surgery. Stop taking horny goat weed at least 2 weeks before surgery.

Are there interactions with medications?

Moderate
Be cautious with this combination.
Estrogens
Horny goat weed might have some of the same effects as estrogen and might increase blood levels of estrogen in some people. Taking horny goat weed with estrogen might increase the effects and side effects of estrogen.
Medications changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates)
Some medications are changed and broken down by the liver. Horny goat weed might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
Medications changed by the liver (Cytochrome P450 2B6 (CYP2B6) substrates)
Some medications are changed and broken down by the liver. Horny goat weed might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)
Some medications are changed and broken down by the liver. Horny goat weed might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.
Medications for high blood pressure (Antihypertensive drugs)
Horny goat weed might lower blood pressure. Taking horny goat weed along with medications that lower blood pressure might cause blood pressure to go too low. Monitor your blood pressure closely.
Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Horny goat weed might slow blood clotting. Taking horny goat weed along with medications that also slow blood clotting might increase the risk of bruising and bleeding.

Are there interactions with herbs and supplements?

Caffeine-containing herbs and supplements
Horny goat weed contains an ingredient that might slow down how quickly the body processes caffeine. Taking it with caffeine-containing herbs and supplements might increase the effects and side effects of caffeine. Examples of supplements that contain caffeine include black tea, coffee, green tea, guarana, and yerba mate.
Herbs and supplements that might lower blood pressure
Horny goat weed might lower blood pressure. Taking it with other supplements that have the same effect might cause blood pressure to drop too much. Examples of supplements with this effect include andrographis, casein peptides, L-arginine, niacin, and stinging nettle.
Herbs and supplements that might slow blood clotting
Horny goat weed might slow blood clotting and increase the risk of bleeding. Taking it with other supplements with similar effects might increase the risk of bleeding in some people. Examples of supplements with this effect include garlic, ginger, ginkgo, nattokinase, and Panax ginseng.

Are there interactions with foods?

There are no known interactions with foods.

How is it typically used?

There isn't enough reliable information to know what an appropriate dose of horny goat weed might be. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult a healthcare professional before using.

Other names

Barrenwort, Épimède, Épimède à Grandes Fleurs, Épimède du Japon, Epimedium, Epimedium acuminatum, Epimedium brevicornum, Epimedium grandiflorum, Epimedium Grandiflorum Radix, Epimedium koreanum, Epimedium macranthum, Epimedium pubescens, Epimedium sagittatum, Epimedium violaceum, Epimedium wushanese, Herba Epimedii, Herbe Cornée de Chèvre, Hierba de Cabra en Celo, Japanese Epimedium, Xian Ling Pi, Yin Yang Huo.

Methodology

To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.

References

  1. Li K, Yu XH, Maskey AR, et al. Cytochrome P450 3A4 suppression by epimedium and active compound kaempferol leads to synergistic anti-inflammatory effect with corticosteroid. Front Pharmacol 2023;13:1042756. View abstract.
  2. Tan K, Yang W, Pang L, Hou F. Differences in clinical characteristics among 726 patients with Chinese herbal medicine- or Western medicine-induced liver injury. Medicine (Baltimore) 2022;101:e29909. View abstract.
  3. Wang J, Cao Y, Feng X, et al. Study on the synergistic and attenuating mechanism of the combination of Epimedium and Ligustri lucidi fructus based on pharmacokinetics. J Sep Sci 2022;45:3382-3392. View abstract.
  4. Hai Y, Zuo L, Wang M, et al. Icariin Alleviates Nonalcoholic Fatty Liver Disease in Polycystic Ovary Syndrome by Improving Liver Fatty Acid Oxidation and Inhibiting Lipid Accumulation. Molecules 2023;28:517. View abstract.
  5. Li P, Zhang L, Guo Z, et al. Epimedium koreanum Nakai-Induced Liver Injury-A Mechanistic Study Using Untargeted Metabolomics. Front Pharmacol 2022;13:934057. View abstract.
  6. Yong EL, Cheong WF, Huang Z, et al. Randomized, double-blind, placebo-controlled trial to examine the safety, pharmacokinetics and effects of Epimedium prenylflavonoids, on bone specific alkaline phosphatase and the osteoclast adaptor protein TRAF6 in post-menopausal women. Phytomedicine 2021;91:153680. View abstract.
  7. Shi S, Wang F, Huang Y, et al. Epimedium for osteoporosis based on Western and Eastern medicine: an updated systematic review and meta-analysis. Front Pharmacol 2022;13:782096. View abstract.
  8. Younger J, Donovan EK, Hodgin KS, Ness TJ. A placebo-controlled, pseudo-randomized, crossover trial of botanical agents for Gulf war illness: Reishi mushroom (Ganoderma lucidum), stinging nettle (Urtica dioica), and Epimedium (Epimedium sagittatum). Int J Environ Res Public Health 2021;18:3671. View abstract.
  9. Irfan M, Kwon TH, Lee DH, et al. Antiplatelet and Antithrombotic Effects of Epimedium koreanum Nakai. Evid Based Complement Alternat Med. Apr 2021;2021:7071987. View abstract.
  10. Huang S, Meng N, Chang B, Quan X, Yuan R, Li B. Anti-inflammatory activity of Epimedium brevicornu maxim ethanol extract. J Med Food. 2018;21:726-733. View abstract.
  11. Teo YL, Cheong WF, Cazenave-Gassiot A, et al. Pharmacokinetics of prenylflavonoids following oral ingestion of standardized epimedium extract in humans. Planta Med. 2019;85:347-355. View abstract.
  12. Indran IR, Liang RL, Min TE, Yong EL. Preclinical studies and clinical evaluation of compounds from the genus Epimedium for osteoporosis and bone health. Pharmacol Ther 2016;162:188-205. doi: 10.1016/j.pharmthera.2016.01.015. View abstract.
  13. Zhong Q, Shi Z, Zhang L, et al. The potential of Epimedium koreanum Nakai for herb-drug interaction. J Pharm Pharmacol 2017;69:1398-408. doi: 10.1111/jphp.12773. View abstract.
  14. Ho CC, Tan HM. Rise of herbal and traditional medicine in erectile dysfunction management. Curr Urol Rep 2011;12:470-8. View abstract.
  15. Corazza O, Martinotti G, Santacroce R, et al. Sexual enhancement products for sale online: raising awareness of the psychoactive effects of yohimbine, maca, horny goat weed, and Ginkgo biloba. Biomed Res Int 2014;2014:841798. View abstract.
  16. Ramanathan VS, Mitropoulos E, Shlopov B, et al. An Enzyte'ing' case of acute hepatitis. J Clin Gastroenterol 2011;45:834-5. View abstract.
  17. Zhao YL, Song HR Fei JX Liang Y Zhang BH Liu QP Wang J Hu P. The effects of Chinese yam-epimedium mixture on respiratory function and quality of life in patients with chronic obstructive pulmonary disease. J Tradit Chin Med. 2012;32:203-207.
  18. Wu H, Lu Y Du S Chen W Wang Y. [Comparative study on absorption kinetics in intestines of rats of epimedii foliunm of Xianlinggubao capsules prepared by different processes]. [Article in Chinese]. Zhongguo Zhong Yao Za Zhi. 2011;36:2648-2652.
  19. Lee, M. K., Choi, Y. J., Sung, S. H., Shin, D. I., Kim, J. W., and Kim, Y. C. Antihepatotoxic activity of icariin, a major constituent of Epimedium koreanum. Planta Med 1995;61:523-526. View abstract.
  20. Chen, X., Zhou, M., and Wang, J. [Effect of epimedium sagittatum on soluble IL-2 receptor and IL-6 levels in patients undergoing hemodialysis]. Zhonghua Nei Ke.Za Zhi. 1995;34:102-104. View abstract.
  21. Liao, H. J., Chen, X. M., and Li, W. G. [Effect of Epimedium sagittatum on quality of life and cellular immunity in patients of hemodialysis maintenance]. Zhongguo Zhong.Xi.Yi.Jie.He.Za Zhi. 1995;15:202-204. View abstract.
  22. Iinuma, M., Tanaka, T., Sakakibara, N., Mizuno, M., Matsuda, H., Shiomoto, H., and Kubo, M. [Phagocytic activity of leaves of Epimedium species on mouse reticuloendotherial system]. Yakugaku Zasshi 1990;110:179-185. View abstract.
  23. Yan, F. F., Liu, Y., Liu, Y. F., and Zhao, Y. X. Herba Epimedii water extract elevates estrogen level and improves lipid metabolism in postmenopausal women. Phytother.Res. 2008;22:1224-1228. View abstract.
  24. Zhao, L., Lan, L. G., Min, X. L., Lu, A. H., Zhu, L. Q., He, X. H., and He, L. J. [Integrated treatment of traditional Chinese medicine and western medicine for early- and intermediate-stage diabetic nephropathy]. Nan.Fang Yi.Ke.Da.Xue.Xue.Bao. 2007;27:1052-1055. View abstract.
  25. Wang, T., Zhang, J. C., Chen, Y., Huang, F., Yang, M. S., and Xiao, P. G. [Comparison of antioxidative and antitumor activities of six flavonoids from Epimedium koreanum]. Zhongguo Zhong.Yao Za Zhi. 2007;32:715-718. View abstract.
  26. Wang, Y. K. and Huang, Z. Q. Protective effects of icariin on human umbilical vein endothelial cell injury induced by H2O2 in vitro. Pharmacol.Res 2005;52:174-182. View abstract.
  27. Yin, X. X., Chen, Z. Q., Dang, G. T., Ma, Q. J., and Liu, Z. J. [Effects of Epimedium pubescens icariine on proliferation and differentiation of human osteoblasts]. Zhongguo Zhong.Yao Za Zhi. 2005;30:289-291. View abstract.
  28. Wang, Z. Q. and Lou, Y. J. Proliferation-stimulating effects of icaritin and desmethylicaritin in MCF-7 cells. Eur.J Pharmacol. 11-19-2004;504:147-153. View abstract.
  29. Ma, A., Qi, S., Xu, D., Zhang, X., Daloze, P., and Chen, H. Baohuoside-1, a novel immunosuppressive molecule, inhibits lymphocyte activation in vitro and in vivo. Transplantation 9-27-2004;78:831-838. View abstract.
  30. Chen, K. M., Ge, B. F., Ma, H. P., and Zheng, R. L. 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;59:61-64. View abstract.
  31. Wu, H., Lien, E. J., and Lien, L. L. Chemical and pharmacological investigations of Epimedium species: a survey. Prog.Drug Res 2003;60:1-57. View abstract.
  32. Chiba, K., Yamazaki, M., Umegaki, E., Li, M. R., Xu, Z. W., Terada, S., Taka, M., Naoi, N., and Mohri, T. Neuritogenesis of herbal (+)- and (-)-syringaresinols separated by chiral HPLC in PC12h and Neuro2a cells. Biol.Pharm Bull 2002;25:791-793. View abstract.
  33. Zhao, Y., Cui, Z., and Zhang, L. [Effects of icariin on the differentiation of HL-60 cells]. Zhonghua Zhong.Liu Za Zhi. 1997;19:53-55. View abstract.
  34. Tan, X. and Weng, W. [Efficacy of epimedium compound pills in the treatment of the aged patients with kidney deficiency syndrome of ischemic cardio-cerebral vascular diseases]. Hunan.Yi.Ke.Da.Xue.Xue.Bao. 1998;23:450-452. View abstract.
  35. Zheng, M. S. An experimental study of the anti-HSV-II action of 500 herbal drugs. J Tradit.Chin Med 1989;9:113-116. View abstract.
  36. Wu, B. Y., Zou, J. H., and Meng, S. C. [Effect of wolfberry fruit and epimedium on DNA synthesis of the aging-youth 2BS fusion cells]. Zhongguo Zhong.Xi.Yi.Jie.He.Za Zhi. 2003;23:926-928. View abstract.
  37. Liang, R. N., Liu, J., and Lu, J. [Treatment of refractory polycystic ovary syndrome by bushen huoxue method combined with ultrasound-guided follicle aspiration]. Zhongguo Zhong Xi Yi Jie He Za Zhi 2008;28:314-317. View abstract.
  38. Phillips M, Sullivan B, Snyder B, et al. Effect of Enzyte on QT and QTc intervals. Arch Intern Med 2010;170:1402-4. View abstract.
  39. Meng FH, Li YB, Xiong ZL, et al. Osteoblastic proliferative activity of Epimedium brevicornum Maxim. Phytomedicine 2005;12:189-93. View abstract.
  40. Zhang X, Li Y, Yang X, et al. Inhibitory effect of Epimedium extract on S-adenosyl-L-homocysteine hydrolase and biomethylation. Life Sci 2005;78:180-6. View abstract.
  41. Yin XX, Chen ZQ, Liu ZJ, et al. Icariine stimulates proliferation and differentiation of human osteoblasts by increasing production of bone morphogenetic protein 2. Chin Med J (Engl) 2007;120:204-10. View abstract.
  42. Shen P, Guo BL, Gong Y, et al. Taxonomic, genetic, chemical and estrogenic characteristics of Epimedium species. Phytochemistry 2007;68:1448-58. View abstract.
  43. Yap SP, Shen P, Li J, et al. Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium. J Ethnopharmacol 2007;113:218-24. View abstract.
  44. Ning H, Xin ZC, Lin G, et al. Effects of icariin on phosphodiesterase-5 activity in vitro and cyclic guanosine monophosphate level in cavernous smooth muscle cells. Urology 2006;68:1350-4. View abstract.
  45. 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 2005;98:295-300. View abstract.
  46. De Naeyer A, Pocock V, Milligan S, De Keukeleire D. Estrogenic activity of a polyphenolic extract of the leaves of Epimedium brevicornum. Fitoterapia 2005;76:35-40. View abstract.
  47. Zhang G, Qin L, Shi Y. Epimedium-derived phytoestrogen flavonoids exert beneficial effect on preventing bone loss in late postmenopausal women: a 24-month randomized, double-blind and placebo-controlled trial. J Bone Miner Res 2007;22:1072-9. View abstract.
  48. 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;31:65-9. View abstract.
  49. Partin JF, Pushkin YR. Tachyarrhythmia and hypomania with horny goat weed. Psychosomatics 2004;45:536-7. View abstract.
  50. Cirigliano MD, Szapary PO. Horny goat weed for erectile dysfunction. Alt Med Alert 2001;4:19-22.
  51. Parisi GC, Zilli M, Miani MP, et al. High-fiber diet supplementation in patients with irritable bowel syndrome (IBS): a multicenter, randomized, open trial comparison between wheat bran diet and partially hydrolyzed guar gum (PHGG). Dig Dis Sci 2002;47:1697-704.. View abstract.
  52. Anon. In vitro screening of traditional medicines for anti-HIV activity: memorandum from a WHO meeting. Bull World Health Organ 1989;67:613-8. View abstract.
  53. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  54. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
Last reviewed - 04/12/2024