About Herbs, Botanicals & Other Products

Scientific Name
Epimedium sagittatum, Epimedium grandiflorum
Common Name

Horny Goat Weed, Yin Yang Huo, Inyokaku, Herba Epimedii

Clinical Summary

Epimedium is a Chinese herb used in traditional medicine to treat fatigue, arthritic and nerve pain, and sexual dysfunction. Use of Epimedium is thought to alter levels of certain hormones. Results from in vitro studies suggest that components of Epimedium exhibit neuroprotective (2) (13), immunomodulatory (3) (4), and anticancer effects (5) (6) (14). Epimedium grandiflorum was reported to have anti-HIV activity in vitro (7). In Asia, Epimedium is used in a herbal formula for cancer treatment (10). The flavonoids present in Epimedium were shown in a randomized trial to prevent bone loss in postmenopausal women (11).
Oral intake of this product resulted in tachyarrhythmia and hypomania in a patient with cardiovascular disease (8). Patients with hormone-sensitive cancers should use Epimedium with caution as it may have estrogenic effects (1).

Purported Uses
  • Fatigue
  • Sexual dysfunction
Constituents
Leaves:
  • Flavonoids
  • Sterols
  • Lignans
  • Sesquiterpenes
  • Prenylflavones
  • Phenolic Glycosides
  • Epimedin C
Mechanism of Action

Icariin, a major constituent of Epimedium, was shown in an in vitro study to decrease the ability of invasion or migration of metastatic cancer cells (5). Icariin is also implicated in differentiation of stem cells into cardiomyocytes involving cell cycle regulation, induction of apoptosis, and p53 modulation (9). An aqueous extract of Epimedium was shown to increase production of antibodies and cytokines in mice (4). Icaritin and desmethylicaritin, compounds derived from Icariin, exhibit estrogen-like activity. However, icariin itself did not show similar activity (1). Icariin may have mild phosphodiesterase-5 inhibition effect (12).

Warnings

Cancer patients may experience symptoms of sexual dysfunction that include painful intercourse, loss of libido, and difficulty in maintaining arousal. These problems may be caused by factors such as stress, hormonal changes, and treatment involving surgery, radiation, chemotherapy, or hormone therapy. Patients should consult and be monitored by a physician when using supplements for sexual dysfunction.
It may be advisable for patients with hormone-sensitive cancers to avoid Epimedium as it may have estrogenic effects (1).

Contraindications
  • Hypersensitivity to Epimedium
  • Cardiovascular disease
Adverse Reactions

Overdose can cause mydriasis, hyperactivities, spasms and cramps, and respiratory depression (11).

Reported (Oral):
According to a case study reported in 2004, a 66-year-old man with congestive heart failure was hospitalized following symptoms of shortness of breath, chest pain, and new-onset symptomatic arrhythmia. He reported to have taken one pill a day of Epimedium for two weeks to increase sexual pleasure. The symptoms were brought under control by administering olanzapine along with lorazepam.

Herb-Drug Interactions

The interactions between Epimedium and prescription drugs have not been studied or reported.

Literature Summary and Critique

Epimedium has been studied with other herbs in formulas for different diseases. There are no clinical trials on its safety or efficacy.

References
  1. Ye HY, Lou YJ. Estrogenic effects of two derivatives of icariin on human breast cancer MCF-7 cells. Phytomedicine 2005; 12(10):735-741.
  2. Li L, Zhou QX, Shi JS. Protective effects of icariin on neurons injured by cerebral ischemia/reperfusion. Chin Med J (Engl ) 2005; 118(19):1637-1643.
  3. Kim JH, et al. Effects of the aqueous extract of Epimedii Herba on the induction of oral tolerance in mice. Biol Pharm Bull 2002; 25(8):1000-1005.
  4. Kim JH, et al. Effects of the aqueous extract of epimedii herba on the antibody responses in mice. Int Immunopharmacol 2001; 1(5):935-944.
  5. Mao H, Zhang L, Wang Y, Li X. Experimental studies of icariin on anticancer mechanism. Zhong Yao Cai 2000; 23(9):554-556.
  6. Mao H, et al. Influence of icariin on cell membrane of highly metastatic human lung tumor cell line. Zhong Yao Cai 1999; 22(1):35-36. (7) In vitro screening of traditional medicines for anti-HIV activity: memorandum from a WHO meeting. Bull World Health Organ 1989; 67(6):613-618.
  7. Partin JF, Pushkin YR. Tachyarrhythmia and hypomania with horny goat weed. Psychosomatics 2004; 45(6):536-537.
  8. Zhu D, et al.Icariin-mediated modulation of cell cycle and p53 during cardiomyocyte differentiation in embryonic stem cells. Eur J Pharmacology 2005; 514:99-110.
  9. Liu J, et al. Clinical Observation on 271 Cases of Non-Small Lung Cancer Treated with Yifei Kangliu Yin (Jin Fu Kang). Chinese Journal of Integrated Traditional and Western Medicine 2001; 7(4):247-250.
  10. Chen J. Chinese Medical Herbology and Pharmcology. City of Industry, CA: Art of Medicine Press, 2004.
  11. 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(7):1072-9.
  12. Dell’Agli M, Galli G, Dal Caero E, et al. Potent inhibition of human phosphodiesterase-5 by icariin derivatives. J Nat Prod. 2008 Sep;71(9):1513-7.
  13. Liu B, Zhang H, Xu C, et al. Neuroprotective effects of icariin on corticosterone-induced apoptosis in primary cultured rat hippocampal neurons. Brain Res. 2011 Feb 23;1375:59-67.
  14. Guo Y, Zhang X, Meng J, Wang ZY. An anticancer agent icaritin induces sustained activation of the extracellular signal-regulated kinase (ERK) pathway and inhibits growth of breast cancer cells. Eur J Pharmacol. 2011 Mar 1. [Epub ahead of print]
How It Works

Bottom Line: There is limited scientific evidence on use of Epimedium. More studies are needed to confirm its safety and efficacy.

Epimedium is a Chinese herb traditionally used to treat fatigue and sexual dysfunction and pain. Cancer patients may experience symptoms of sexual dysfunction that include painful intercourse, loss of libido, and difficulty in maintaining arousal. These problems may be caused by factors such as stress, hormonal changes, and cancer treatments. Epimedium is thought to affect levels of certain hormone. But no clinical trials have been conducted to verify such effects. It has been used along with other herbs for cancer; however, it is unclear if it has any anticancer effect by itself.

Purported Uses
  • Fatigue
    Epimedium is traditionally used for fatigue but it has not been studied in clinical trials.
  • Sexual dysfunction
    Epimedium is traditionally used in herbal formulas for sexual dysfunction. More studies are needed to verify such effects.
Research Evidence

Clinical trials have not been performed to study the effects of Epimedium.

Patient Warnings

Sexual dysfunction could be a result of physical, biological, or psychological disorders or a result of cancer treatment. Patients should talk to a doctor before using this product.
It may be advisable for patients with hormone-sensitive cancers to avoid Epimedium as it may have estrogenic effects (1).

Do Not Take If
  • You are sensitive to Epimedium
  • You have heart disease (Epimedium has been shown to cause rapid irregular heartbeat and hyperactivity in a patient with heart disease).
Side Effects
  • Rapid irregular heartbeat (tachyarrhythmia)
  • Increase in energy and mood changes (hypomania)
Aliases
Horny Goat Weed
Yin Yang Huo
E-mail your questions and comments to aboutherbs@mskcc.org.