Horny goat weed

Synopsis

Horny Goat Weed (Epimedium spp.): A Comprehensive Reference

1. Identity and Botanical Classification

Horny goat weed is the common English name for plants belonging to the genus Epimedium, a group of herbaceous flowering plants in the family Berberidaceae. The genus consists of approximately 52 species of herbaceous flowering plants. It belongs to the genus Epimedium, a group of flowering plants native to China, and is known by many names, including barrenwort, fairy wings, bishop's hat, and yin yang huo in traditional Chinese herbalism.

The 2020 edition of the Chinese Pharmacopoeia includes five kinds of medicinal Epimedium: Epimedium brevicornu Maxim., Epimedium pubescens Maxim., Epimedium koreanum Nakai, Epimedium sagittatum Maxim., and Epimedium wushanense T. S. Ying. In traditional Chinese medicine, the dried aerial parts of these species are collectively referred to as Herba Epimedii or Epimedium Folium. Herba Epimedii was first described in Shennong's Chinese Materia Medica (202 BC–220 AD) as dry leaves of Epimedium brevicornu Maxim., Epimedium sagittatum (Sieb. et Zucc.) Maxim., Epimedium pubescens Maxim., or Epimedium koreanum Nakai.

This traditional tonic Chinese medicine was first documented in the Shennong Materia Medica Classic and is widely distributed throughout China. It thrives in temperate and subtropical regions, exhibiting a preference for shaded and humid environments. Epimedium Folium typically grows in the understory of forests, in shrubs along ditches, or in damp areas on mountain slopes.

Etymology and Common Names

Horny goat weed earned its name from the behavior of goats that acted friskier after eating Epimedium plants. The name of the herb in Mandarin, yin yang huo, roughly corresponds to "weed for licentious goat." Other common names include barrenwort, bishop's hat, fairy wings, rowdy lamb herb, and the Japanese Inyokaku. In traditional Chinese medicine, the extract is also called Xian Ling Pi or Yin Yang Huo.

Common Preparations and Forms

Extracts of the leaves and stems of horny goat weed are purported to have activity in improving sexual dysfunction, menstrual irregularities, osteoporosis, asthma, nephritis, and cardiovascular disease. Over 200 chemical constituents have been identified in the plant, among which are flavonoids, lignans, ionones, phenol glycosides, and sesquiterpenes. Commercially, the herb is most commonly available as:

Encapsulated dried powder or extract (whole-herb or standardized to a specific percentage of icariin content)
Tinctures and liquid extracts
Teas prepared from the dried leaves
Standardized-extract capsules calibrated to icariin content (typically ranging from 10% to 60% icariin by weight)

In Chinese patent medicine, Epimedium is widely used in various modern Chinese patent medicine products and traditional Chinese medicine preparations. Notable Chinese pharmaceutical preparations include "Xianling Gubao Oral Preparation" and "Zhuanggu Joint Pill."

2. Traditional and Historical Use

Ancient Chinese Medicine

Epimedii Folium has been used as a common traditional Chinese medicine for more than 2,000 years in China. In the Chinese medicinal monographs Shennong Ben Cao Jing (Shennong Herbals, ~1,600 AD) and Ben Cao Gang Mu (Compendium of Materia Medica, ~1578), herbal Epimedii was recorded as "invigorating sex, strengthening muscles and bones."

This traditional tonic Chinese medicine was first documented in the Shennong Materia Medica Classic. In the theory of medicinal properties of traditional Chinese medicine, the taste of Epimedium Folium is considered spicy and sweet, and its properties are mild. During the Northern and Southern Dynasties, there was a legend that a shepherd discovered that after consuming a wild grass growing in bushes, the sexual drive of his goats increased.

Geographic Traditions

Epimedium, commonly known as horny goat weed or Yin Yang Huo, is commonly used as a tonic, aphrodisiac, anti-rheumatic, and anti-cancer agent in traditional herbal formulations in Asian countries such as China, Japan, and Korea. Epimedium Folium is frequently employed in China, Japan, and South Korea for its medicinal properties, including kidney tonification, aphrodisiac effects, muscle and bone strengthening, as well as wind and dampness dispelling.

Traditional Indications

According to Chinese medicine, Herba Epimedii can tonify kidney Yang, strengthen the bones and sinews, and relieve joint pain. In classical TCM, the herb was prescribed for:

Fatigue, arthritic pain, nerve pain, and sexual dysfunction.
Impotence, asthma, bronchitis, cervical dysplasia, congestive heart failure, leucorrhoea, leukopenia, and viral infections of the heart (in modern Chinese herbal medicine, often in combination with other herbs).
Menopause in women, often combined with Morinda.
The treatment of sinew and bone disorders, "painful impediment caused by wind-dampness," numbness, spasms, hypertension, coronary heart disease, menopausal syndrome, bronchitis, and neurasthenia.

Epimedium is a traditional Chinese tonic in Chinese medicine, which is often used to treat bone diseases and strengthen the kidney.

Method of Traditional Preparation

TCM practitioners historically employed the dried leaf as the primary medicinal part, prepared as decoctions (boiled water extracts), wines, or combined multi-herb formulas. Traditional Chinese medicine practitioners use this herb to increase the Yang energies; for instance, it would be used to enhance male sexual performance.

3. Key Constituents and Active Compounds

Overall Phytochemical Profile

Previous studies have identified more than 260 compounds in Epimedium, including flavonoids, lignans, violacein, phenolic glycosides, and other compounds representing various categories of secondary metabolites. Modern studies have found that it contains a series of compounds, such as flavonoids, polysaccharides, organic acids, etc. Flavonoids, in particular, have been extensively studied and are considered the main active ingredients.

Primary Bioactive Flavonoids

The major bioactive compounds present within this plant include icariin, icaritin, and icariside II. Many studies have proposed four major flavonoids—icariin, epimedin A, epimedin B, and epimedin C—to be integrative quality indicators of herbal epimedium.

Icariin is the principal marker compound. Icariin (molecular formula: C₃₃H₄₀O₁₅, molecular weight: 676.67 g/mol) is a prenylated flavonoid considered as the main bioactive of Herba Epimedii. Icariin is a prenylated flavonol glycoside isolated from Epimedium herb, and has been shown to be the main bioactive component. Flavonoids are the major active components in the leaves of Epimedium plants, and total flavonoids, particularly icariin, have been defined as quality indicators in the Chinese Pharmacopoeia.

Additional noteworthy compounds include:

Icaritin — a metabolite of icariin with phytoestrogenic properties and independent pharmacological activity, including completed phase I/II clinical trials for hepatocellular carcinoma. Icaritin (ICT), a phytoestrogen, is extracted from the dried stems and leaves of Epimedii; a phase I/II clinical trial of ICT for hepatocellular carcinoma has been completed, and two phase III studies are currently underway in China.
Icariside II (Baohuoside I) — a hydrolysis product of icariin that also acts on PDE5.
Epimedin A, B, and C — additional prenylflavonoids serving as quality markers in Chinese Pharmacopoeia analysis.
Polysaccharides — polysaccharides have been proven as being biologically active for antitumor, anti-oxidation, and immunity improvement.
Lignans and alkaloids — contemporary research on Epimedium has led to the isolation of flavonoids, lignans, and alkaloids from its aerial parts.

The active ingredients that have anti-inflammatory, immunomodulatory, antiviral, and hepatoprotective activities are believed to be flavonoids, such as icariin, icaritin, or epimedin.

4. Mechanisms of Action

PDE5 Inhibition and Nitric Oxide Pathway

The most extensively characterized mechanism of icariin is inhibition of phosphodiesterase type 5 (PDE5). The natural product icariin inhibits human phosphodiesterase-5 (PDE5) and represents a unique pharmacophore for treating erectile dysfunction, pulmonary hypertension, and other diseases. Icariin is an effective oral agent and a PDE5 inhibitor for the treatment of erectile dysfunction (ED) through stimulation of the NO/cGMP signalling pathway via PDE5 inhibition in the penile cavernosum.

To clarify the mechanism of the therapeutic action of icariin on erectile dysfunction, PDE5 was isolated from human platelet and PDE4 from rat liver tissue. The inhibitory effects of icariin on PDE5 and PDE4 activities were investigated by the two-step radioisotope procedure. Icariin and papaverine showed dose-dependent inhibitory effects on PDE5 and PDE4 activities. The IC₅₀ of icariin and papaverine on PDE5 were 0.432 µmol/L and 0.680 µmol/L, respectively, and those on PDE4, 73.50 µmol/L and 3.07 µmol/L, respectively. These data demonstrate that icariin is a selective PDE5 inhibitor, with far less activity against PDE4.

Notably, icariin demonstrated a significant nitric oxide (NO)-dependent vasorelaxation of precontracted coronary arterial rings with intact endothelium in a concentration-dependent manner, via the activation of endothelial nitric oxide synthase protein and NO-cyclic guanidine monophosphate (cGMP) pathway.

Osteogenic Mechanisms

Icariin promotes bone formation by stimulating osteogenic differentiation of BMSCs (bone marrow-derived mesenchymal stem cells), while inhibiting osteoclastogenic differentiation and the bone resorption activity of osteoclasts. Furthermore, icariin has been shown to be more potent than other flavonoid compounds in promoting osteogenic differentiation and maturation of osteoblasts. Animal experiments further confirm that icariin has estrogen-like effects, capable of inhibiting RANKL-induced osteoclast bone resorption function. This effect may be achieved by regulating the imbalance of the RANKL/OPG signaling axis — basic research shows that icariin can down-regulate the expression of RANKL, while promoting the secretion of OPG, thereby blocking the osteoclast differentiation pathway.

Estrogenic / Phytoestrogenic Activity

Icariin, a flavonoid phytoestrogen derived from Herba epimedii, has been reported to exert estrogenic effects in bone and activate phosphorylation of estrogen receptor (ER)α in osteoblastic cells. However, it is unclear whether icariin selectively exerts estrogenic activities in bone without inducing undesirable effects in other estrogen-sensitive tissues. Icariin, the primary hydrophilic component of Epimedium brevicornu Maxim., has been widely used to treat menopausal women with hypertension since it was discovered to be a plant sex hormone.

Anti-Inflammatory and Antioxidant Mechanisms

Attributing to its wide range of pharmacological properties, including anti-osteoporosis, anti-inflammation, anti-oxidative stress, anti-depression, and anti-tumor properties, icariin is being considered a potential therapeutic agent for a wide variety of disorders. Various signaling pathways, including NFκB/NALP3, IGF-1, MiR-223-3p/NALP3, TLR4/NFκB, and WNT1/β-catenin, are involved in the different biological actions exerted by icariin.

Cardiovascular and Atheroprotective Mechanisms

Emerging evidence has shown that icariin possesses multiple atheroprotective functions, through multiple mechanisms, including attenuating DNA damage, correcting endothelial dysfunction, inhibiting the proliferation and migration of smooth muscle cells, repressing macrophage-derived foam cell formation and inflammatory responses, as well as preventing platelet activation. All of these protective effects, combined with its lipid-modulatory effects, contribute to the broad atheroprotective effects of icariin.

Neuroprotective Mechanisms

Pharmacokinetically, icariin is widely distributed in the body including the brain, indicating that icariin can pass through the blood-brain barrier. Recent studies suggest that icariin produces neuroprotective effects and can significantly increase the viability of hippocampal neurons treated with corticotropin releasing hormone (CRH). It alleviates cognitive deficits in the senescence accelerated mouse prone 8 (SAMP8) Alzheimer's disease animal model by inhibiting the formation of amyloid plaques through the downregulation of amyloid-beta 1-42.

5. Scientific Evidence by Area of Use

5.1 Sexual Function and Erectile Dysfunction

Preclinical evidence — The most clearly established mechanism is PDE5 inhibition. In vitro enzyme-inhibition studies in isolated human platelet PDE5 showed that icariin displayed dose-dependent inhibitory effects on PDE5, with an IC₅₀ of 0.432 µmol/L. Surface plasmon resonance and molecular docking assays revealed that phosphodiesterase 5A (PDE5A) is an important target of icariin in mouse spermatogonial stem cells, and that icariin decreased the expression level of PDE5A.

Clinical evidence — Clinical trials specifically in human erectile dysfunction remain limited. Clinical trials have been conducted on the use of Epimedium species for the treatment of conditions including hypertension, coronary artery disease, and as an aphrodisiac. However, no randomized clinical trial-level data appear to exist in the literature at the level of those available for pharmaceutical PDE5 inhibitors. The active compound icariin has shown potential benefits in improving penile hemodynamics and tissue effects in animal studies, suggesting neurotrophic and phosphodiesterase type 5 inhibiting effects. Overall, human clinical evidence for erectile dysfunction specifically remains very limited; current evidence is primarily preclinical (in vitro and animal studies), and extrapolation to humans requires caution.

5.2 Bone Health and Osteoporosis

This is the area with the strongest and most direct clinical evidence in humans.

Key clinical trial — A 24-month randomized, double-blind, placebo-controlled clinical trial was performed evaluating the effect of Epimedium-derived phytoestrogen flavonoids (EPFs) on BMD, bone turnover biochemical markers, serum estradiol, and endometrial thickness in postmenopausal women. One hundred healthy late postmenopausal women, with a BMD T-score at the lumbar spine between −2 and −2.5 SD, were randomized into EPF treatment group (n = 50; a daily dose of 60 mg icariin, 15 mg daidzein, and 3 mg genistein) or placebo control group (n = 50). All participants received 300 mg elemental calcium daily. BMD, bone turnover biochemical markers, serum estradiol, and endometrial thickness were measured at baseline and 12 and 24 months after intervention. Eighty-five participants completed the trial. Results showed that Epimedium-derived phytoestrogen flavonoids were able to exert beneficial effects on preventing bone loss in late postmenopausal women, without resulting in a detectable hyperplasia effect on the endometrium.

Systematic review findings — Epimedium, a kidney-tonifying traditional Chinese medicine, has the potential to regulate bone metabolism through multiple targets, but clinical evidence is scattered and inconclusive. A 2025 systematic review and meta-analysis searching PubMed, Embase, Cochrane Library, CNKI, and Wanfang Database found that serum alkaline phosphatase (ALP) was significantly reduced (MD = −8.78; 95% CI: −12.80, −4.77; p<0.0001), while bone-specific alkaline phosphatase (BALP) increased (MD = 6.73; 95% CI: 3.32, 10.14; p=0.0001). Adverse reactions were low, mainly mild gastrointestinal reactions or skin allergies. Epimedium can effectively improve bone density and clinical symptoms in patients with primary osteoporosis, with good safety, making it a potential alternative or adjunctive treatment option, but more high-quality studies are needed to verify long-term efficacy.

Recent clinical trials have reported positive effects on bone health, suggesting that compounds or extracts of Epimedium have the potential to be developed as agents, alone or in combination with other drugs, to prevent or delay the onset of osteoporosis and reduce the risk of hip fractures. Icariin, the core component of Epimedium in TCM, faces clinical translation challenges due to its low bioavailability and complex mechanism.

Evidence strength — Moderate. There is at least one well-designed RCT in humans and several systematic reviews that collectively suggest benefit for bone mineral density in postmenopausal women. However, trials are often small, predominantly Chinese in origin, and may not all meet contemporary methodological standards. More large-scale, independent replications are needed.

5.3 Menopausal Symptoms and Estrogenic Effects

Because the in vivo effects of phytoestrogens are similar to estrogens and their actions are mediated through similar estrogen receptors (ERs), there are increasing concerns for the safety of using phytoestrogens. The ideal phytoestrogens for management of menopause-associated symptoms should exhibit selectivity in estrogen-sensitive tissues without undesirable stimulation of the growth of reproductive tissues.

Research indicates icariin may behave as a selective estrogen receptor modulator (SERM)-like agent. The 24-month postmenopausal RCT described above found beneficial effects on bone without detectable endometrial hyperplasia, suggesting tissue selectivity. However, it remains unclear whether icariin selectively exerts estrogenic activities in bone without inducing undesirable effects in other estrogen-sensitive tissues.

Evidence strength — Preliminary to moderate for bone-related menopausal effects. Data on other menopausal symptoms (hot flashes, mood, sleep) are insufficient at the clinical level.

5.4 Cardiovascular Effects

Icariin, the main constituent of Epimedii Herba, is a flavonoid. It has been shown to provide neuroprotection, anti-tumor, anti-osteoporosis, and cardiovascular protection. The endothelial protection, anti-inflammatory, hypolipidemic, antioxidative stress, and anti-apoptosis properties of icariin can help stop the progression of cardiovascular and neurological diseases. The most promising effect of icariin at the cardiovascular level is the promotion of stem cell differentiation into beating cardiomyocytes, which suggests its likely application in cardiac cell therapy or tissue engineering. Moreover, icariin has also been evaluated for prevention and treatment of thrombosis in atherosclerosis, as it reduces platelet adhesiveness and aggregation besides a decrease in serum cholesterol.

Evidence strength — Predominantly preclinical (in vitro and animal). There is a lack of large, well-designed human clinical trials specifically for cardiovascular outcomes. Findings are mechanistically promising but not yet established at the clinical level.

5.5 Neuroprotection and Cognitive Function

Recent animal experimental studies indicate that icariin, a major bioactive component of epimedium, may effectively treat Alzheimer's disease, cerebral ischemia, depression, Parkinson's disease, multiple sclerosis, as well as delay aging. In an animal study specifically targeting neurological disease, icariin (ICA) was investigated for its effects on learning and memory as well as pathological features in APP/PS1 transgenic Alzheimer's disease mice, based on its activity as a PDE5 inhibitor stimulating the NO/cGMP signalling pathway.

Evidence strength — Preclinical only. No large, well-controlled human clinical trials have been published on cognition or neurodegenerative disease outcomes. Animal data are mechanistically consistent but cannot be directly extrapolated to humans.

5.6 Anticancer Activity

In recent years, there has been great interest in scientific investigation of the purported anti-cancer properties of icariin and its derivatives. Data from in vitro and in vivo studies suggests these compounds demonstrate anti-cancer activity against a wide range of cancer cells, which occurs through various mechanisms such as apoptosis and cell cycle modulation. Epimedium showed anti-osteoporotic, neuroprotective, immunomodulatory, and anticancer effects, as well as anti-HIV activity in preclinical studies. Epimedium derivatives also produced radiosensitizing effects and reversed multidrug resistance in tumor cells.

Evidence strength — Preclinical. Icaritin (a metabolite) has undergone phase I/II clinical trials for hepatocellular carcinoma in China, but large confirmatory trials for icariin itself are not yet published in the peer-reviewed literature.

5.7 Immunomodulation

Icariin can exhibit both immunomodulatory and anti-inflammatory effects, antioxidant activity, anti-aging effects, and improvement of cardiovascular function, in addition to being anti-bacterial and anti-tumor. Modern pharmacological studies have demonstrated that these constituents possess a range of pharmacological activities, including anti-inflammatory, antioxidant, anti-tumour, anti-hepatic injury, immunomodulatory, and hypoglycaemic effects.

Evidence strength — Predominantly in vitro and animal model data. Human clinical evidence for immunomodulatory outcomes is lacking.

6. Dosage Forms and Dosages Reported in Studies

Dosages reported in the scientific literature vary substantially depending on the condition studied, extract concentration, and whether the metric is the whole-herb powder or isolated icariin. The following are only doses reported in cited peer-reviewed sources:

Postmenopausal bone health (human RCT): A daily dose of 60 mg icariin, 15 mg daidzein, and 3 mg genistein; all participants also received 300 mg elemental calcium daily. 60 mg icariin daily was active in the postmenopausal women/bone health trial, and might serve as the lowest active dose currently known.
Human pharmacokinetics study: Icariin, as a 20% icariin concentration in a 500 mg horny goat weed capsule, was used in a human safety and pharmacokinetics study.
Oral bioavailability study (animal): A study on horny goat weed dosed at 1.64 g/kg (4.38 mg/kg icariin) orally showed a C_max of 2.41 ± 0.2 µg/mL, an AUC of 23.62 ± 1.37 µg/h/mL, a T_max of 1.55 ± 0.53 hours, and a half-life of 0.11 ± 0.07 hours.

Bioavailability Considerations

Icariin is not a stable compound in the human intestine due to enzymes present. Icariin, along with three other compounds native to the parent plant (epimedin A, B, and C), as prenylated flavonoids, are rapidly digested into their respective metabolites in the intestinal environment via hydrolysis. These four compounds mostly have their rhamnose sugar cleaved off during this process. Co-ingestion of a lactase phlorizin hydrolase inhibitor increased the absorption of the active ingredients, preserving 40–62% of the original icariin content. Without said lactase inhibitor, bioavailability of straight icariin is approximately 12%.

Comparing horny goat weed ingestion alone against a combination with two other herbs (Nepal dock root and Ficus hirta yahl), the C_max of icariin was higher (3.13 ± 0.29 µg/mL) as was the AUC (30.84 ± 3.68 µg/h/mL); the half-life was 0.35 ± 0.32 hours and the T_max was prolonged to 2.06 ± 0.15 hours when co-ingested.

7. Safety Considerations and Drug Interactions

General Safety Profile

Horny goat weed is a low growing plant with leathery leaves found in wetlands in many areas of the world, extracts of which have been used in traditional medicine as a tonic, aphrodisiac, and antirheumatic agent. Oral forms of horny goat weed have not been linked to serum aminotransferase elevations or to instances of clinically apparent liver injury. The NIH LiverTox database assigns a likelihood score of E (unlikely cause of clinically apparent liver injury).

Although epimedium is associated with adverse reactions, the toxic side effects of icariin are considered negligible. Studies have shown that when NIH mice were gavaged with Epimedium total flavonoids at 36 g/kg/day for 7 days (1,440 times the standard human dose), no mortality was observed.

Hepatotoxicity: Case Reports and Warnings

There have been rare reports of liver injury in patients taking multi-ingredient products that contain epimedium, although the attribution of injury to horny goat weed has not always been very clear. In large registries and case series on drug and herbal product-induced liver injury, horny goat weed has not been listed. Furthermore, cases of severe clinically apparent liver injury have not been reported with horny goat weed.

However, individual case reports have raised hepatotoxicity concerns. Horny goat weed contains icariin, which may cause liver injury through oxidative stress or immune-related mechanisms. This case emphasizes the importance of detailed histories regarding herbal supplement use in patients with liver dysfunction. Separately, in recent years, the clinical preparations of Epimedium, such as "Zhuanggu Joint Pill" and "Xianling Gubao Oral Preparation," have been issued adverse reaction notices by the National Medical Products Administration of China. Among them, 2,665 cases showed that "Xianling Gubao Oral Preparation" damaged the liver, gallbladder, and gastrointestinal systems in patients.

Reported Adverse Events

Several cases have been published concerning toxic reactions to Epimedium. One case describes new-onset tachycardia and hypomania after two weeks of Epimedium use. Abdominal pain and nausea have been reported as well.

Drug Interactions

Horny goat weed has been shown to affect the enzyme CYP3A4, which is involved in metabolizing many drugs. A case of increased opiate cravings in a patient on buprenorphine has been reported. The purported mechanism was felt to relate to the induction of CYP3A4 metabolism. Buprenorphine is also metabolized by CYP3A4.

Epimedium extracts contain potent phytoestrogens, which can have strong estrogen-like effects in the body. This raises theoretical concerns about interactions with hormone-sensitive conditions and drugs that affect estrogen metabolism. Because the in vivo effects of phytoestrogens are similar to estrogens and their actions are mediated through similar estrogen receptors, there are increasing concerns for the safety of using phytoestrogens.

Musculoskeletal Reports

A published case report describes a patient experiencing severe muscle spasms and elevated creatine kinase and creatinine associated with horny goat weed use. The absence of randomized clinical trial data on the safety and effectiveness of Epimedium species supplements has been noted by several authors, including concerns for drug-drug interactions.

Product Quality Concerns

Herbal supplements in many countries are not regulated as strictly as prescription drugs. Braunstein et al. (2012) analyzed sexual enhancement supplements marketed in the U.S. and detected novel and undeclared PDE5 inhibitors (including sildenafil analogs) in products labeled as natural supplements, underscoring the risk of undisclosed pharmaceutical adulterants in commercial horny goat weed products.

8. Summary of Evidence Strengths by Area

Bone health / osteoporosis: Moderate human clinical evidence; at least one high-quality 24-month RCT with significant findings, supported by multiple systematic reviews and meta-analyses. Limitations include trial size and need for independent replication.
Erectile dysfunction / sexual function: Strong mechanistic (in vitro PDE5 inhibition) and animal data; robust human clinical RCT evidence is lacking. Proof of concept exists but clinical translation has not been fully demonstrated.
Menopausal symptom management: Preliminary positive evidence for bone preservation; limited data on other menopausal symptoms.
Cardiovascular and atheroprotection: Preclinical evidence is mechanistically robust; human clinical trials for cardiovascular endpoints are absent or insufficient.
Neuroprotection / cognition: Preclinical data only; no high-quality human clinical trials.
Cancer: Preliminary in vitro/animal data; icaritin (metabolite) is in active phase III trials for liver cancer in China, but icariin itself lacks confirmed human anti-cancer clinical data.
Immunomodulation: Preclinical only.