D-aspartic acid (DAA) is an amino acid found in the pituitary gland and testes, where it is involved in releasing the hormones LH and testosterone. As a supplement it is sold as a testosterone booster for men and athletes.
Also known as: DAA, D-aspartate, sodium D-aspartate.
Trials in resistance-trained men used 3 g or 6 g a day for 14 days (Melville 2015) and 6 g a day for 12 weeks (Melville 2017). These are study protocols, not a recommendation.
It is sold in the US as a dietary supplement. Under the 1994 dietary supplement law (DSHEA), FDA does not approve dietary supplements before they are marketed, and the maker, not FDA, is responsible for safety and labeling.
What studies show: in a 2009 study of 23 men given D-aspartate for 12 days (with 20 on placebo), LH and testosterone rose (Topo 2009). Later trials in men who lift did not find this: 6 g a day for 14 days lowered total and free testosterone, while 3 g had no effect (Melville 2015), and 6 g a day for 12 weeks did not change testosterone or training gains but lowered estradiol by about 16% (Melville 2017). A 2017 systematic review found 23 animal studies and only 4 human studies, with inconsistent results in people, and called the human evidence sparse and of poor quality.
The trials were small (22 to 43 men) and short. The sources here do not describe side effects or drug interactions.
We could not find a single published half-life or time to peak for D-aspartic acid that applies to a supplement dose, so we do not list one.
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