Examining the Effects of Herbs on Testosterone Concentrations in Men: A Systematic Review.
Level 1 - systematic review of randomized trials
Systematic review of randomized controlled trials
PubMed 33150931 · doi:10.1093/advances/nmaa134
What was done
Authors systematically searched 4 databases for randomized controlled trials published between 2001 and 2019 evaluating the effects of single herbal ingredients, fractions, or binding proteins on testosterone concentrations in men aged 18 years or older (PROSPERO CRD42020173623).
What was found
The review identified 13 herbs across 32 randomized controlled trials. Overall, 9 out of 32 studies reported statistically significant increases in testosterone concentrations. Positive effects were reported for fenugreek seed extracts and ashwagandha root and root/leaf extracts, with some evidence for Asian red ginseng and forskohlii root extract. Only 6 of 32 studies were judged to have a low risk of bias, and 16 of 32 evaluated men younger than 40 years old.
Why it matters
Herbs are widely marketed as alternatives to testosterone replacement therapy, but the evidence base is narrow, limited to very few extracts, and mostly tested in young, nonclinical populations.
Limits
Only 6 of 32 trials had a low risk of bias. Half of the studies evaluated men under 40 rather than patients with clinical androgen deficiency. The abstract reports substantial heterogeneity in dosages, extracts, and study designs, small sample sizes, and a lack of definitive safety and efficacy data.
Cited by
- contradicts Supplements like tribulus, D-aspartic acid, and fenugreek have been disproven as effective testosterone boosters.