Supplement analysis backed by scientific evidence · PT

← All supplements
Limited evidenceMen's health

Testosterone Booster Formulas

Most of the ingredients in over-the-counter testosterone boosters have no human evidence for raising testosterone, and several have evidence they do not. If your testosterone is genuinely low, this is a medical problem with a medical treatment — not a supplement problem.

What the science says

  • The category's ingredients are not supported by the literature Limited evidence

    An analysis of 50 top-selling "T booster" products found 109 distinct ingredients; only about 24% had any human data showing a testosterone increase, roughly 10% had data showing a decrease, and over 60% had no human data at all. Many also contained vitamins and minerals at above the tolerable upper intake level.

  • Correcting a deficiency is not the same as boosting Moderate evidence

    Zinc, vitamin D and magnesium can raise testosterone in men who are genuinely deficient, but supplementing men with normal status produces no meaningful change. This nuance is the basis for nearly every marketing claim in the category.

  • The best-studied botanicals produce small or hormone-neutral effects Limited evidence

    Ashwagandha and fenugreek are the two ingredients with the most supportive trials, but reported testosterone increases are small, sometimes within assay noise, and trials are frequently small, short (8-12 weeks) and manufacturer-funded. Tribulus terrestris — the category's signature ingredient — has repeatedly failed to raise testosterone in controlled trials, including in trained athletes.

  • Some products are spiked or contain unlisted steroids Moderate evidence

    Case reports document drug-induced liver injury and vascular events after over-the-counter testosterone boosters, and regulatory testing has repeatedly found designer anabolic steroids and prohormones in this category. That is the most likely explanation when a supplement produces dramatic hormonal effects.

Dosage & safety

Studied doseTypical labels: 500-1,000 mg tribulus, 300-600 mg ashwagandha extract, 500-600 mg fenugreek extract, 3,000 mg D-aspartic acid, 30-50 mg zinc, 2,000-5,000 IU vitamin D. Studied doses with any support: ashwagandha root extract 300-600 mg/day for 8-12 weeks; fenugreek extract 500-600 mg/day; zinc 25-30 mg/day and vitamin D 2,000-4,000 IU/day only where deficiency is documented. D-aspartic acid at 3 g/day has failed in resistance-trained men and higher doses lowered testosterone in one trial.
SafetyZinc above 40 mg/day long-term causes copper deficiency and anaemia; some products stack zinc, vitamin D and vitamin A above upper limits. Fenugreek causes a maple-syrup body odour and may lower blood glucose. Ashwagandha has case reports of hepatotoxicity and thyroid hormone elevation, and is contraindicated in pregnancy. Drug-induced liver injury and renal infarction have been reported with unlabelled ingredients in this category. Athletes are at real risk of anti-doping violations from prohormone contamination. Anyone with symptoms of hypogonadism (low libido, fatigue, loss of morning erections) should get serum testosterone measured rather than self-treating.

Scientific references

Where to buy

SIXSTAR, Testosterone Booster, 60 Caplets

View on iHerb

Referral link — this site may earn a commission on purchases.

Related in Men's health