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Horny goat weed

Supplement botanical men's health
Aka: Epimedium, icariin, yin yang huo
Brands seen in Singapore: NOW Foods, Nutricost, Lemme, Nature's Craft, Force Factor
Third-party tested: Lemme, Force Factor certify other products with NSF Certified for Sport, but nothing for horny goat weed.Certification is granted per product, so check the tub you actually own. Not being listed is not the same as failing.
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Traditional tonic and aphrodisiac use — human data thin
Studied for
The one placebo-controlled arm ran 30 days per dose
Pros & cons
Pros
  • One placebo-controlled crossover trial in 29 men exists
  • Long recorded use as a tonic in asian herbal practice
Cons
  • That trial: no symptom change at either dose
  • Hepatobiliary adverse reports have grown with use
  • Some epimedium flavonoids are tied to liver toxicity
Sources
  1. Anti-cancer properties of the naturally occurring aphrodisiacs: icariin and its derivatives (Tan et al., Front Pharmacol 2016) · read 2026-08-27
    what it says
    “Epimedium (family Berberidaceae), 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”
  2. A placebo-controlled, pseudo-randomized, crossover trial of botanical agents for Gulf War Illness (Younger et al., Int J Environ Res Public Health 2021) · read 2026-08-27
    what it says
    “We used a placebo-controlled, pseudo-randomized, crossover design to test the effects of … epimedium (Epimedium sagittatum) in 29 men with GWI … 30 days of placebo, followed by 30 days each of lower-dose and higher-dose botanical”
  3. A placebo-controlled, pseudo-randomized, crossover trial of botanical agents for Gulf War Illness (Younger et al., Int J Environ Res Public Health 2021) · read 2026-08-27
    what it says
    “Epimedium showed no significant decreases of GWI symptoms in the lower (p = 0.936) or higher (p = 0.183) dose conditions … Epimedium does not appear to beneficially affect GWI symptom severity”
  4. Screening of hepatotoxic components of Epimedium brevicornu Maxim. by liver microfluidic-organ-chip (Cui et al., J Ethnopharmacol 2026) · read 2026-08-27
    what it says
    “Epimedium brevicornu Maxim., a traditional tonic Chinese herbal medicine traditionally regarded as non-toxic … the number of adverse reactions such as hepatobiliary toxicity has gradually increased, thereby raising concerns about its safety”
  5. Evaluation on the potential for hepatotoxic components from Herba Epimedii to induce apoptosis in HepG2 cells (Zhang et al., Molecules 2024) · read 2026-08-27
    what it says
    “The potential hepatotoxicity of Herba Epimedii is a focal point … the flavonoid constituents of Herba Epimedii, sagittatoside A, icariside I, baohuoside I and icaritin, are related to the hepatotoxicity of this herb”
  6. HSA — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines, GL-CHPB-1-012 Rev 001 (Oct 2025) · read 2026-08-27
    what it says
    “The objective of this guideline is to highlight the substances of concern when used in HS and TM and is not meant to be an exhaustive list [Epimedium spp. / horny goat weed not listed in Annex A or B]”
  7. iHerb Singapore — Horny Goat Weed category (default order) · read 2026-08-27
    what it says
    “NOW Foods, Horny Goat Weed Extract, 90 Tablets … Nutricost, Horny Goat Weed, 600 mg … Lemme, Play, Daily Intimacy Gummies … Nature's Craft, Horny Goat Weed, Xxtra Strength Herbal Complex … Force Factor, Fundamentals, Horny Goat Weed Max”
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Updated 2026-08-30. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.