Herbs (Global Traditional) · Traditional Chinese Medicine
Epimedium sagittatum (Horny Goat Weed)
Moderate Evidencebotanical4 PubMed Studies
Hermetica Superfood Encyclopedia
Horny goat weed (Epimedium sagittatum) is a traditional Chinese medicinal herb containing icariin as its primary bioactive compound. Icariin acts as a phosphodiesterase-5 (PDE5) inhibitor and phytoestrogen, potentially supporting sexual function and bone health through improved blood flow and estrogen receptor modulation.
Epimedium sagittatum, commonly known as Horny Goat Weed, is a low-growing perennial plant in the Berberidaceae family native to wetlands throughout Asia, parts of Europe, and Africa. The aerial parts, particularly leaves and stems, are harvested and processed via standard botanical extraction methods to yield flavone-standardized powders, typically containing 10% flavones tested as icariin by UV.
Clinical evidence for Epimedium sagittatum is limited, with no large-scale RCTs or meta-analyses identified. Small trials have shown promising effects for high blood pressure, coronary artery disease, and sexual satisfaction, but these have not been confirmed in rigorous prospective controlled trials. In vitro and animal studies demonstrate cytotoxic effects on hepatoma and leukemia cells, though no PubMed PMIDs for key human RCTs are available.
Clinically studied doses include tablets or capsules of 250-500 mg daily. A phytoestrogen extract containing 60 mg icariin and 15 mg daidzein has been taken safely for up to 2 years, while an icariin-containing extract has been used for up to 6 months. Commercial extracts are often standardized to 10% flavones tested as icariin. Consult a healthcare provider before starting any new supplement.
Epimedium sagittatum is a medicinal herb rather than a dietary staple, so its nutritional profile is characterized primarily by bioactive phytochemicals rather than macronutrient content. Dried aerial parts contain approximately 5–10% total flavonoids by weight, with icariin being the principal bioactive compound at concentrations of 1–5% in dried leaf material (varying significantly by plant part, season, and processing method). Icariin is a prenylated flavonol glycoside and serves as the primary marker compound for standardized extracts. Other key flavonoids include icariside I, icariside II (des-O-methylicariiin), epimedin A, epimedin B, and epimedin C, collectively present at 0.5–3% of dry weight. Baohuoside-1 (icariside II) is a deglycosylated metabolite formed during digestion and is considered more bioavailable than icariin itself. The herb contains polysaccharides at approximately 8–15% dry weight, contributing immunomodulatory activity. Lignans including epimedokoreanin and magnoflorine alkaloids are present in trace amounts (<0.1%). Phytosterols including beta-sitosterol are present at approximately 0.1–0.3%. Mineral content includes calcium (~1,200–1,800 mg/100g dry weight), magnesium (~200–300 mg/100g), potassium (~800–1,200 mg/100g), manganese (~15–25 mg/100g), and zinc (~2–5 mg/100g), though these are not primary reasons for therapeutic use. Crude protein content is approximately 10–15% dry weight and crude fiber approximately 20–30% dry weight. Bioavailability note: Icariin has poor oral bioavailability (~5–10%) due to its glycoside structure; intestinal and hepatic metabolism converts it to more active aglycones (icaritin) and icariside II, which show greater membrane permeability. Lipid-based delivery systems and piperine co-administration have been shown experimentally to improve absorption. Total phenolic content is approximately 30–60 mg gallic acid equivalents per gram of dried extract.
The primary bioactive compound icariin inhibits phosphodiesterase-5 (PDE5) enzyme, increasing cyclic GMP levels and promoting smooth muscle relaxation in blood vessels. Icariin also acts as a phytoestrogen, binding to estrogen receptors alpha and beta to influence bone metabolism and cardiovascular function. Additionally, it may enhance nitric oxide production through endothelial nitric oxide synthase (eNOS) activation.
Limited clinical evidence comes from small trials with 20-60 participants studying sexual function outcomes. One 12-week study showed modest improvements in erectile function scores compared to placebo, though sample sizes were insufficient for definitive conclusions. Preliminary cardiovascular studies suggest potential blood pressure reductions of 5-8 mmHg, but these findings require replication in larger, well-controlled trials. Most research relies on animal studies and in vitro data rather than robust human clinical evidence.
Common side effects include dizziness, nausea, dry mouth, and nosebleeds at doses above 20g daily of raw herb. Horny goat weed may interact with blood thinners like warfarin due to potential anticoagulant effects, and could enhance hypotensive medications. It should be avoided during pregnancy and breastfeeding due to lack of safety data and potential hormonal effects. Individuals with hormone-sensitive conditions should exercise caution due to its phytoestrogenic properties.
