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Amino acids & derivatives

D-Aspartic Acid

D-Aspartic acid / D-aspartate

D-Aspartic acid (DAA) is an amino acid sold mainly around testosterone and sports-performance marketing, not established cognitive benefit. Human testosterone findings are inconsistent, and controlled trials in resistance-trained men did not show reliable testosterone or training advantages. The active catalog has 25 DAA listings from two vendors, mostly powders; compare the D form, serving strength, powder versus capsule format, freshness, and label data before price.

Food DerivedSports NutritionClinical ResearchLimited Human EvidenceMixed EvidencePopulation Specific Evidence
Updated August 2026/5 min read/8 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
01

What is it?

Not an established cognitive nootropic5
D-Aspartic acid is marketed mainly around testosterone and sports performance. The limited human evidence is inconsistent, and it does not establish a focus, memory, or mental-energy benefit.

What D-Aspartic acid is

1

D-Aspartic acid (DAA) is the D form of aspartic acid. Current products are mainly powders and capsules; compare the stated D form, serving strength, and format rather than assuming bulk powder and capsules are interchangeable.

02

Names, aliases and forms

Common NameD-Aspartic Acid
AbbreviationDAA
Scientific NameD-aspartate
Spelling VariantD-Aspartic acid
Chemical Name(2R)-2-aminobutanedioic acid
Pubchem Cid83887
03

Mechanisms of action

Hormone marketing is stronger than the evidence

5

Early work raised questions about DAA and reproductive-hormone markers, but the systematic review found human results inconsistent and sparse. That does not support a reliable testosterone, fertility, or cognitive claim.

04

Potential effects and evidence map

The human evidence base is small and inconsistent. Early endocrine findings did not translate into reliable testosterone, strength, or body-composition advantages in later resistance-trained-men trials. DAA should not be presented as a cognitive enhancer, a reliable testosterone booster, or a general fertility or sports-performance intervention.

Effect domainMagnitudeGrade
Physical energy / endurance6
UnknownConfidence: Medium

Not established for improving strength, body composition, or training outcomes in resistance-trained men.

Note Controlled resistance-trained-men trials did not show a reliable performance advantage.

0/5
D
05

Typical dosages and timing

Trial context only43-6 g/day

Resistance-trained adult-men trials tested 3 g/day and 6 g/day. These are study conditions, not a recommended dose for general use, libido, fertility, or cognitive purposes.

06

Timing & effect horizon

Effect horizonUnknown
Unknown
One 12-week trial is not a consumer cycle6

One controlled resistance-trained-men trial used a 12-week intervention. That research duration does not establish an onset, a cycle, or a general self-use schedule.

07

Safety, side effects and risk profile

Human safety data are limited5
The available human studies are small and focused on hormone or training outcomes. They do not establish long-term consumer safety or support detailed DAA-specific interaction and special-population claims.
Evidence uncertainty6
Confidence: Medium

Long-term consumer safety is not established by the cited short-term human trials; this is a safety-data gap, not evidence of known harm.

Note This reflects a safety-data gap, not evidence of a known DAA-specific harm.

1/5
D
08

Legal and regulatory status

United States8

As of 2026-08-01, dietary supplements sold in the United States are not FDA-approved for safety or effectiveness before marketing. This is U.S. regulatory context, not an ingredient-specific approval or a statement about other markets.

09

How it compares

DAA7

The human evidence does not establish a reliable testosterone increase, and later resistance-trained-men trials did not show a training advantage. Compare that evidence with label marketing before assuming a hormone or sports benefit.

10

Practical buying and quality notes

  • As of 2026-08-01, the active catalog has 19 powders and 6 capsules across two vendors. Do not use stale or uncrawled rows, zero-dose fields, invalid bulk normalization, or duplicate crawl rows as a current price, capsule-strength, or active-dose ranking.1
  • Check that the label names D-aspartic acid, identify powder versus capsule format, verify serving size and capsule count, and prefer a lot-specific certificate of analysis where available. A low bulk-price-per-gram figure is not comparable with a capsule unit price.1
11

FAQ

Does D-Aspartic Acid raise testosterone?

5

Do not assume that. The systematic review found the human evidence inconsistent and sparse, while later resistance-trained-men trials did not show a reliable testosterone increase.

Can DAA powder and capsules be compared by price?

1

Not directly. Compare powder price per gram only within similarly fresh powder listings, and compare capsules by the verified DAA amount per serving and capsule count. Do not use zero-dose, stale, uncrawled, or invalidly normalized rows as a current ranking.

Is DAA a cognitive nootropic?

5

Not on the available human evidence. The main studies concern hormone markers and resistance training, not focus, memory, or mental energy outcomes.

12

References

  1. PubChem Compound Summary for D-Aspartic acid, CID 83887.
  2. Topo E, Soricelli A, D'Aniello A, Ronsini S, D'Aniello G. The role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and rats. Reprod Biol Endocrinol. 2009.
  3. Willoughby DS, Leutholtz B. 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 HPG axis in resistance-trained men. Nutr Res. 2013.
  4. Melville GW, Siegler JC, Marshall PW. Three and six grams supplementation of d-aspartic acid in resistance trained men. J Int Soc Sports Nutr. 2015.
  5. Roshanzamir F, Safavi SM. The putative effects of D-Aspartic acid on blood testosterone levels: a systematic review. Int J Reprod Biomed. 2017.
  6. Melville GW, Siegler JC, Marshall PWM. The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: a randomised controlled trial. PLoS One. 2017.
  7. Morgado A, Tsampoukas G, Sokolakis I, Schoentgen N. Do testosterone boosters really increase serum total testosterone? A systematic review. Int J Impot Res. 2024.
  8. U.S. FDA. Information for Consumers on Using Dietary Supplements.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.