| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Muscle Mass/Strength Systematic review: DAA cannot alter body composition in trained males; strength gains from training only | NoneNo effect | 80 people |
Supplement
Aspartate is an amino acid the body uses to build proteins and pass signals between nerve cells, and its D form helps regulate hormone release. In a small group of untrained men, testosterone rose 42% over 12 days, and a combination with ubiquinol and zinc improved sperm motility over three months, though the evidence is limited. In resistance-trained men, testosterone did not rise and fell, and a review found no change in body composition.
- Updated
- How we grade
- 11 studies cited
- Best evidence
- Grade C
- Conditions studied
- 3
- Outcomes
- 4
- Graded outcomes
- 0022
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Serum Testosterone (Untrained Men) 42% increase in testosterone after 12 days of 3.12g/day in untrained men; LH increased 33% | Improves (the measure goes up) | Moderate effect | 23 people | |||
| Serum Testosterone (Trained Athletes) No increase in testosterone in resistance-trained men; 6g/day actually decreased total and free testosterone | NoneNo effect | 100 people |
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Sperm Motility 2660mg DAA + ubiquinol + zinc improved progressive sperm motility and testosterone (p=0.009) over 3 months | Improves (the measure goes up) | Moderate effect | 90 people |
Key findings
- Serum Testosterone (Untrained Men)Improves (the measure goes up)
- Sperm MotilityImproves (the measure goes up)
- Serum Testosterone (Trained Athletes)
Shop Aspartate
Third-party tested Aspartate products. The evidence above is limited, so read it before you buy.
- Grade C
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Studies cited
11 studies from PubMed
- Evaluation of in vivo supplementation of 2660 mg D-aspartic acid and 200 mg ubiquinol and 10 mg zinc on different semen parameters in idiopathic male infertility: a randomized double blind placebo controlled study
- New Insights into D-Aspartate Signaling in Testicular Activity
- Effects of oral d-aspartate on sperm quality in B6N mice
- The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial
- The putative effects of D-Aspartic acid on blood testosterone levels: A systematic review
- In vitro effects of zinc, D-aspartic acid, and coenzyme-Q10 on sperm function
- D-aspartate affects NMDA receptor-extracellular signal-regulated kinase pathway and upregulates androgen receptor expression in the rat testis
- d-Aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained men
- D-Aspartic acid: an endogenous amino acid with an important neuroendocrine role
- Occurrence of D-aspartic acid in human seminal plasma and spermatozoa: possible role in reproduction
- Occurrence of D-aspartic acid and N-methyl-D-aspartic acid in rat neuroendocrine tissues and their role in the modulation of luteinizing hormone and growth hormone release