D-Aspartic Acid
Research reviewed: Up until 03/2026
D-Aspartic Acid (D-Aspartic Acid (DAA)) is a dietary supplement with 8 published peer-reviewed studies involving 0 participants, researched for Testosterone Support, Sports Performance.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Testosterone Support
StrongSports Performance
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Testosterone Support
To compare the efficacy of D-aspartic acid supplementation on testosterone levels with fluoxetine in resistance-trained men
Study Type
Randomized, controlled
Purpose
To compare the efficacy of D-aspartic acid supplementation on testosterone levels with fluoxetine in resistance-trained men
Dose
6 grams DAA/day
Participants
Resistance-trained men
Duration
12 weeks
Results
Total testosterone was significantly reduced in 6g DAA group, and free testosterone was significantly reduced compared to placebo.
How They Measured It
Total testosterone, free testosterone, LH levels
To evaluate D-aspartic acid supplementation effects on testosterone in resistance-trained men over 3 months
Study Type
Randomized, controlled trial
Purpose
To evaluate D-aspartic acid supplementation effects on testosterone in resistance-trained men over 3 months
Dose
D-aspartic acid supplementation
Participants
Resistance-trained men
Duration
3 months
Results
D-aspartic acid supplementation had no significant effect on serum testosterone, free testosterone, or body composition in resistance-trained men.
How They Measured It
Serum testosterone, free testosterone, body composition
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
Study Type
Randomised, double-blind, placebo-controlled
Purpose
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
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
The Effects of Six-Gram D-Aspartic Acid Supplementation on the Testosterone, Cortisol, and Hematological Responses of Male Boxers Subjected to 11 Days of Nocturnal Exposure to Normobaric Hypoxia
Study Type
Randomised, double-blind, placebo-controlled
Purpose
The Effects of Six-Gram D-Aspartic Acid Supplementation on the Testosterone, Cortisol, and Hematological Responses of Male Boxers Subjected to 11 Days of Nocturnal Exposure to Normobaric Hypoxia
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Dietary supplementation with barley sprouts and d-aspartic acid improves reproductive hormone concentrations, testicular histology, antioxidant status, and mRNA expressions of apoptosis-related genes in aged broiler breeder roosters
Study Type
Randomised, double-blind, placebo-controlled
Purpose
Dietary supplementation with barley sprouts and d-aspartic acid improves reproductive hormone concentrations, testicular histology, antioxidant status, and mRNA expressions of apoptosis-related genes in aged broiler breeder roosters
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Impacts of different antioxidants sources on semen quality and sperm fertilizing ability of Muscovy ducks under high ambient temperature
Study Type
Randomised, double-blind, placebo-controlled
Purpose
Impacts of different antioxidants sources on semen quality and sperm fertilizing ability of Muscovy ducks under high ambient temperature
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Sports Performance
To synthesize effects of D-aspartic acid supplementation on testosterone and training outcomes
Study Type
Systematic review
Purpose
To synthesize effects of D-aspartic acid supplementation on testosterone and training outcomes
Dose
3-6 grams/day
Participants
Meta-analysis of multiple RCTs in trained men
Duration
12 weeks typical
Results
DAA shows increases in testosterone in untrained men but no changes or reductions in resistance-trained men. Evidence shows DAA is ineffective at improving training outcomes.
How They Measured It
Literature synthesis of RCT evidence
To evaluate D-aspartic acid supplementation on testosterone and hormonal responses in resistance-trained men undergoing heavy training
Study Type
Randomized, double-blind, controlled
Purpose
To evaluate D-aspartic acid supplementation on testosterone and hormonal responses in resistance-trained men undergoing heavy training
Dose
D-aspartic acid supplementation
Participants
Resistance-trained men
Duration
28 days
Results
DAA had no significant effect on resting LH or testosterone/cortisol ratio during intensive training.
How They Measured It
Serum testosterone, cortisol, LH, training outcomes
Frequently Asked Questions
Common questions about D-Aspartic Acid research
There are currently 8 peer-reviewed studies on D-Aspartic Acid (D-Aspartic Acid (DAA)), involving 0 total participants. Research covers Testosterone, Male fertility, Athletic performance. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (7 human studies), and reported outcomes.
D-Aspartic Acid has been researched for: Testosterone, Male fertility, Athletic performance. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 7 out of 8 studies are human trials. Human trials carry more weight in our evidence scoring system.
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