This product is not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the Food and Drug Administration.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider before using herbs, especially if you are pregnant, nursing, taking medications, or have a medical condition.
Epimedium, commonly known as Horny Goat Weed, contains icariin as its primary active compound. Icariin acts as a natural phosphodiesterase type 5 (PDE5) inhibitor, similar to pharmaceutical medications like sildenafil. By inhibiting PDE5, icariin helps maintain higher levels of cyclic GMP in penile tissue, promoting smooth muscle relaxation and improved blood flow. This mechanism supports erectile function. Research evidence is limited to preclinical studies (Evidence Level C), with no large-scale human clinical trials confirming efficacy. Traditional use in Chinese medicine spans centuries for kidney yang deficiency and sexual health.
Can I take Epimedium with Viagra or other PDE5 inhibitors?
No, Epimedium should not be combined with pharmaceutical PDE5 inhibitors like sildenafil (Viagra), tadalafil (Cialis), or vardenafil. Since icariin in Epimedium also inhibits PDE5, taking it with these medications can cause excessive PDE5 inhibition, leading to dangerously low blood pressure, prolonged erections (priapism), and cardiovascular complications. This interaction is well-documented. Additionally, Epimedium may interact with blood pressure medications and hormone therapies. Always consult a healthcare provider before combining herbal supplements with prescription medications, especially for cardiovascular or hormonal conditions.
What is the recommended daily dosage for Epimedium extract?
The standard adult dosage for Epimedium is 500-1000mg of standardized extract daily, containing 20-40% icariin concentration. This provides approximately 100-400mg of active icariin per day. Lower doses may be sufficient for general tonic use, while higher doses are typically used for specific sexual health concerns. Standardized extracts are preferred over raw herb powder for consistent icariin delivery. Evidence for optimal dosing is limited (Evidence Level C), based primarily on traditional use and pharmacological studies rather than clinical trials. Divide doses throughout the day with meals to reduce gastrointestinal upset.
Is Epimedium safe to take during pregnancy or breastfeeding?
Epimedium is considered unsafe during pregnancy and breastfeeding. The herb has demonstrated hormonal effects in research studies and may stimulate uterine contractions, potentially risking miscarriage or premature labor. Icariin and related compounds can affect estrogen and testosterone pathways, which may interfere with fetal development. There is insufficient safety data for breastfeeding use. Women who are pregnant, trying to conceive, or breastfeeding should avoid Epimedium entirely. Additionally, those with hormone-sensitive conditions, including certain cancers, should not use this herb without medical supervision.
Does Epimedium actually increase testosterone levels?
Research on Epimedium's effects on testosterone is limited and inconclusive. While some animal studies suggest icariin may support testosterone pathways and testicular function, human clinical evidence is lacking (Evidence Level C). Epimedium is marketed for testosterone support, but this claim is not well-substantiated in scientific literature. The herb's primary mechanism involves PDE5 inhibition rather than direct hormone stimulation. Traditional Chinese Medicine uses Epimedium as a kidney yang tonic for overall vitality, not specifically for raising testosterone. Men seeking testosterone support should consult a healthcare provider for evidence-based treatments and appropriate testing.
PubMed-compiled information sheet
This sheet was compiled from PubMed (NIH) abstracts using AI assistance. Every factual claim is cited to a real PubMed article (see the source list). It has not yet been human-reviewed — confirm with a healthcare provider before use.
Compiled from 29 PubMed articles · model: gemma4:31b
Summary
Epimedium, commonly known as Horny Goat Weed, is a genus of medicinal plants used traditionally as a tonic and aphrodisiac [PMID:35998248, PMID:21215308]. Modern research indicates it possesses broad pharmacological activities, including osteoprotective, neuroprotective, and anti-inflammatory effects [PMID:38801026, PMID:27445824].
Background
Epimedium (family Berberidaceae) is a genus comprising approximately 52 to 62 species, with many distributed in China [PMID:21215308, PMID:36120133]. It is known by various names, including Yin Yang Huo, Barrenwort, and Horny Goat Weed [PMID:21215308, PMID:27445824].
Traditional uses
Traditionally used in Asian countries as a tonic, aphrodisiac, and anti-rheumatic agent [PMID:35998248, PMID:27445824]. In Traditional Chinese Medicine (TCM), it is used to tonify kidney and yang, strengthen tendons and bones, and treat impotence and spermatorrhea [PMID:38801026, PMID:40185257].
Active compounds
The primary active components are prenyl-flavonoids, specifically icariin, icaritin, and icariside II [PMID:21215308, PMID:39066475, PMID:27445824]. Other identified constituents include epimedin A, B, and C, baohuoside I, isopentenyl flavonols, neolignans, and water-soluble polysaccharides composed of mannose, rhamnose, galacturonic acid, glucose, and galactose [PMID:37108810, PMID:37894651, PMID:28278623, PMID:36746589].
Mechanism of action
Icariin promotes osteogenic differentiation by upregulating alpha-enolase (Eno1) and mediating the BMP/Smad4 signaling pathway [PMID:37125075]. It modulates bone remodeling by activating Wnt/β-catenin and PI3K/Akt signaling to promote osteoblasts, while suppressing RANKL-mediated NF-κB activation to inhibit osteoclasts [PMID:42193945]. Additionally, Epimedium-derived exosome-like nanovesicles may reshape gut microbiota and suppress the TLR4/NF-κB pathway to reduce systemic inflammation [PMID:41432450].
Clinical evidence
Evidence AOsteoporosis
Epimedium has been evaluated as an adjunctive or alternative to conventional pharmacotherapy to improve bone mineral density (BMD) and effective rate [PMID:35431937].
Evidence CSexual Dysfunction
Used traditionally for impotence and sexual dysfunction, with modern pharmacology demonstrating efficacy in strengthening yang [PMID:21215308, PMID:38801026].
Evidence CNeurodegenerative Diseases
Icariin exhibits potential preventive and therapeutic effects in models of Alzheimer's disease by inhibiting amyloid β (1-42) production and BACE-1 expression [PMID:30342950].
Safety & adverse effects
Oral forms of horny goat weed have not been linked to serum aminotransferase elevations or clinically apparent liver injury [PMID:35998248].
Evidence summary
The evidence consists primarily of review articles and preclinical in vitro/in vivo studies (Level C and D), with one systematic review and meta-analysis (Level A) focusing on osteoporosis.
PubMed sources
1.PMID: 35998248 (2012) — Botanicals and Their Bioactive Phytochemicals for Women's Health. · Pharmacological reviews
2.PMID: 32089233 (2020) — Pharmacological effects of icariin. · Advances in pharmacology (San Diego, Calif.)
4.PMID: 21215308 (2011) — The genus Epimedium: an ethnopharmacological and phytochemical review. · Journal of ethnopharmacology
5.PMID: 40992067 (2025) — Epimedium brevicornu Maxim.-derived extracellular vesicle-like particles stimulate VEGF-mediated angiogenesis to alleviate postmenopausal osteoporosis. · Phytomedicine : international journal of phytotherapy and phytopharmacology
Government sources
No direct government monograph is available for this herb. The content below is AI-generated and has not been verified against an authoritative government source. Use the search links to check official sources before relying on this information.
6.PMID: 26268839 (2016) — An Evidence-Based Systematic Review of Yin Yang Huo (Epimedium spp.) by the Natural Standard Research Collaboration. · Journal of dietary supplements
7.PMID: 40873547 (2025) — Progress in the application of epimedium and its major bioactive components in the treatment of orthopedic diseases. · Frontiers in pharmacology
8.PMID: 39066475 (2024) — Cancer-Related Therapeutic Potential of Epimedium and Its Extracts. · Nutrition and cancer
9.PMID: 37108810 (2023) — The Effect of Epimedium Isopentenyl Flavonoids on the Broiler Gut Health Using Microbiomic and Metabolomic Analyses. · International journal of molecular sciences
10.PMID: 36120133 (2022) — Taxonomy of Epimedium (Berberidaceae) with special reference to Chinese species. · Chinese herbal medicines
11.PMID: 27445824 (2016) — Anti-Cancer Properties of the Naturally Occurring Aphrodisiacs: Icariin and Its Derivatives. · Frontiers in pharmacology
12.PMID: 29075193 (2017) — Icariin, an Anti-atherosclerotic Drug from Chinese Medicinal Herb Horny Goat Weed. · Frontiers in pharmacology
13.PMID: 30342950 (2019) — An outline for the pharmacological effect of icariin in the nervous system. · European journal of pharmacology
14.PMID: 37894651 (2023) — Advancements in the Biotransformation and Biosynthesis of the Primary Active Flavonoids Derived from Epimedium. · Molecules (Basel, Switzerland)
15.PMID: 36746589 (2023) — Research progress on the extraction technology and activity study of Epimedium polysaccharides. · Carbohydrate polymers
16.PMID: 37525296 (2023) — Effects of genus Epimedium in the treatment of osteoarthritis and relevant signaling pathways. · Chinese medicine
17.PMID: 37029621 (2024) — A new flavonoid from Epimedium brevicornu Maxim. · Natural product research
18.PMID: 35431937 (2022) — Epimedium for Osteoporosis Based on Western and Eastern Medicine: An Updated Systematic Review and Meta-Analysis. · Frontiers in pharmacology
19.PMID: 37125075 (2023) — Icariin promotes osteogenic differentiation by upregulating alpha-enolase expression. · Biochemistry and biophysics reports
20.PMID: 40185257 (2025) — Epimedium and its chemical constituents in cancer treatment: A comprehensive review of traditional applications, antitumor effects, pharmacokinetics, delivery systems, and toxicology. · Journal of ethnopharmacology
21.PMID: 38801026 (2024) — Epimedium Linn: A Comprehensive Review of Phytochemistry, Pharmacology, Clinical Applications and Quality Control. · Chemistry & biodiversity
22.PMID: 38027566 (2023) — A literature review on Epimedium, a medicinal plant with promising slow aging properties. · Heliyon
23.PMID: 41432450 (2026) — Epimedium-Derived Exosome-like Nanovesicles Regulate Lipid Metabolism via the "Gut-Kidney Axis" for Multitargeted Inhibition of Sepsis-Associated Acute Kidney Injury. · ACS applied materials & interfaces
24.PMID: 22041065 (2011) — Flavonol glycosides from Epimedium pubescens. · Chemical & pharmaceutical bulletin
25.PMID: 8862041 (1996) — Flavonoids from Epimedium wanshanense. · Phytochemistry
26.PMID: 28278623 (2017) — Anti-inflammatory neolignans from Epimedium pseudowushanese. · Natural product research
27.PMID: 42193945 (2026) — Plant-Derived Bioactive Ingredients for Osteoporosis and Bone Regeneration: Mechanisms, Pharmacology, and Delivery Strategies. · Cells