'Testosterone Boosting' Supplements Composition and Claims Are not Supported by the Academic Literature.
Level 4 - case-series / case-control
Cross-sectional market analysis and literature review of commercial dietary supplement contents and claims.
PubMed 31385468 · doi:10.5534/wjmh.190043
What was done
The authors evaluated the active ingredients and advertised claims of 50 commercial "testosterone boosting" supplements identified through a Google search. A PubMed literature search was conducted to evaluate published evidence supporting or refuting claims regarding testosterone levels for each identified component. Each ingredient's dosage was also evaluated against the Recommended Daily Allowance (RDA) and the US Food and Drug Administration upper tolerable intake level (UL).
What was found
Across the 50 products, 109 unique components were identified (mean 8.3 per product). Claimed benefits included "boost T" (90%), "improve libido" (50%), and "feel stronger" (48%). On PubMed, 24.8% of supplements contained ingredients with evidence showing an increase in testosterone, 10.1% had data showing a decrease, 18.3% had data showing no change, and 61.5% had no published data regarding their effect on testosterone. Supplements frequently contained high amounts of vitamins and minerals: median RDA was 1,291% for vitamin B12, 807.6% for vitamin B6, 272% for zinc, 200% for vitamin B5, and 187.5% for vitamin B3. Thirteen products (26%) exceeded the UL for zinc, vitamin B3, or magnesium.
Why it matters
Most commercial testosterone-boosting supplements lack academic literature supporting their primary claims, occasionally include components with evidence of lowering testosterone, and frequently contain supra-therapeutic vitamin or mineral doses exceeding safe upper limits.
Limits
The study evaluated single ingredients rather than finished proprietary formulations in clinical trials. Product selection was limited to the first 50 results from a single search engine query, and chemical analyses were not performed to verify actual product contents against label claims.
Cited by
- contradicts Correcting clinical deficiencies in vitamin D, zinc, and magnesium can result in an incremental increase of 100 to 150 ng/dL in total testosterone.