D-Aspartic Acid (DAA)
What it is
Amino acid that may stimulate luteinizing hormone and testicular testosterone release via the hypothalamic-pituitary-gonadal axis.
What the evidence says
Evidence does not support DAA as a testosterone booster in healthy, trained men. While an early study in untrained men suggested a transient rise, a 12-week randomized controlled trial in resistance-trained men found no change in total or free testosterone at 6 g/day, and a separate trial found 6 g/day actually decreased total testosterone (~12.5%) and free testosterone, with no performance benefit. The weight of controlled evidence is null-to-negative.
Studied at 3-6 g/day; higher doses (6 g/day) have been associated with reduced rather than increased testosterone in trained men, so it is not recommended for this purpose.
Educational summary of doses studied — not a recommendation. Talk to a clinician before starting any supplement.
Sources (2)
- Three and six grams supplementation of d-aspartic acid in resistance trained men — Journal of the International Society of Sports Nutrition (PMC4384294) (2015)
- The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial — PLOS One (PMC5571970) (2017)
Educational summary of published research, checked against primary sources and linked inline. Not medical advice; supplements are not FDA-evaluated to treat disease. See our editorial policy.