Last verified: 17 days ago
D-Aspartic Acid
Also known as: DAA, D-Asp, D-aspartate
Evidence under review. — Not yet rated
Amino acid supplement with weak evidence for testosterone support; results are inconsistent across studies.
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What it does
D-Aspartic Acid (DAA) is a naturally occurring amino acid found in various tissues of the body. It is marketed primarily as a testosterone booster, with some studies suggesting it may modestly...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
2660-6000 mg daily based on study doses
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Found in
What the Science Says
D-Aspartic Acid (DAA) is a naturally occurring amino acid found in various tissues of the body. It is marketed primarily as a testosterone booster, with some studies suggesting it may modestly raise testosterone levels and improve sperm motility in infertile men when combined with other nutrients like CoQ10 and zinc. However, studies in healthy, trained athletes show little to no effect on testosterone or related hormones, even at doses of 3–6 grams per day over 2 weeks.
What It Doesn't Do
Won't reliably boost testosterone in healthy, active men. No evidence it builds muscle or improves athletic performance on its own. Short-term use in trained athletes shows zero effect on key hormones. Not a proven standalone fertility treatment.
Evidence-Based Benefits
May improve progressive sperm motility in infertile men when combined with CoQ10 and zinc.
Weak EvidenceEffective at: 2660 mg/day (with CoQ10 and zinc)
Supporting studies (click to view on PubMed):
May modestly raise total testosterone in men with idiopathic infertility when combined with other nutrients.
Weak EvidenceEffective at: 2660 mg/day (with CoQ10 and zinc)
Supporting studies (click to view on PubMed):
Absorption & Bioavailability
Unknown — no pharmacokinetic data provided in the available studies. Animal data suggests tissue accumulation occurs with regular dosing.
Red Flags to Watch For
- Most positive results come from studies using DAA combined with other ingredients (CoQ10, zinc), making it impossible to isolate DAA's contribution
- Studies in trained athletes consistently show no testosterone-boosting effect, contradicting common marketing claims
- Long-term safety data is lacking; animal studies suggest D-amino acids accumulate in tissues with prolonged use
- Many products contain DAA as part of proprietary blends, making it impossible to verify you're getting a studied dose
Products Containing D-Aspartic Acid
See how D-Aspartic Acid is used in these analyzed products:
Frequently Asked Questions
What does D-Aspartic Acid do?
Amino acid supplement with weak evidence for testosterone support; results are inconsistent across studies.
What is the effective dose of D-Aspartic Acid?
2660-6000 mg daily based on study doses
Is D-Aspartic Acid safe?
Most positive results come from studies using DAA combined with other ingredients (CoQ10, zinc), making it impossible to isolate DAA's contribution
What doesn't D-Aspartic Acid do?
Won't reliably boost testosterone in healthy, active men.
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25