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Types of D-Aspartic Acid: Forms & Bioavailability

Evidence:Preliminary
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This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Forms Comparison

FormBioavailabilityBest For
D-Aspartic Acid (free acid)ModerateMost common supplemental form; standard for testosterone support
D-Aspartic Acid Sodium Salt (DAA-SS)Moderate-HighBetter solubility; sometimes used in capsule formulations
D-Aspartic Acid Calcium Chelate (D-AA-CC)ModerateChelated form marketed as having enhanced activity

D-Aspartic Acid (free acid)

Bioavailability: Moderate. Best for: Most common supplemental form; standard for testosterone support.

D-Aspartic Acid Sodium Salt (DAA-SS)

Bioavailability: Moderate-High. Best for: Better solubility; sometimes used in capsule formulations.

D-Aspartic Acid Calcium Chelate (D-AA-CC)

Bioavailability: Moderate. Best for: Chelated form marketed as having enhanced activity.

References

  1. RCTWilloughby DS, Leutholtz B. (2013). D-aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones. Nutrition Research. DOI PubMed
  2. RCTMelville GW, Siegler JC, Marshall PW. (2015). Three and six grams supplementation of d-aspartic acid in resistance trained men. Journal of the International Society of Sports Nutrition. DOI PubMed
  3. RCTGamalEl Din SF, A M E, Elkhiat Y, Hussein T, et al. (2025). 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.. Archivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica. DOI PubMed
  4. RCTPłoszczyca K, Czuba M, Zakrzeska A, Gajda R (2023). 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.. Nutrients. DOI PubMed
  5. Crewther B, Witek K, Draga P, Zmijewski P, et al. (2019). Short-Term d-Aspartic Acid Supplementation Does Not Affect Serum Biomarkers Associated With the Hypothalamic-Pituitary-Gonadal Axis in Male Climbers.. International journal of sport nutrition and exercise metabolism. DOI PubMed
  6. Melville GW, Siegler JC, Marshall PWM (2017). The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial.. PloS one. DOI PubMed
  7. Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, et al. (2012). The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial.. Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences. PubMed
Show 2 more references
  1. Tricco AC, Vandervaart S, Soobiah C, Lillie E, et al. (2012). Efficacy of cognitive enhancers for Alzheimer's disease: protocol for a systematic review and network meta-analysis.. Systematic reviews. DOI PubMed
  2. RCTTopo E, Soricelli A, D'Aniello A, et al. (2009). The role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and rats. Reproductive Biology and Endocrinology. DOI PubMed