The putative effects of D-Aspartic acid on blood testosterone levels: A systematic review.
Level 2 - randomized trial
Systematic review including heterogeneous animal and human studies
What was done
Authors conducted a systematic review searching PubMed, ISI Web of Science, ProQuest, and Scopus up to October 2015 for studies evaluating the effect of D-aspartic acid (D-Asp) on blood testosterone levels. Out of 396 retrieved records, 23 animal studies and 4 human studies were included.
What was found
Exogenous D-aspartic acid increased blood testosterone levels in male animal models, dependent on species, sex, and organ site. Results across human studies were inconsistent, and the abstract does not report specific numerical values, effect sizes, or dosages.
Why it matters
Despite its widespread promotion as an over-the-counter testosterone booster for male infertility and athletic enhancement, existing clinical evidence in humans remains sparse and inconclusive.
Limits
Only 4 human studies were identified, and the authors note they were limited in number and of poor quality. The abstract does not provide specific participant characteristics, sample sizes, intervention durations, dosages, or numerical outcomes.
Cited by
- supports Supplements like tribulus, D-aspartic acid, and fenugreek have been disproven as effective testosterone boosters.