D-aspartic Acid Benefits – How Can this Amino Acid Help?

D-aspartic acid was discovered in 1827 when scientists were researching the components of asparagus juice.

When scientists realized aspartic acid is naturally produced in the human body, it was classified as an amino acid. However, only in the last decade has this amino acid received attention for the many benefits it offers athletes.[1]

D-Aspartic Acid Benefits

Because research is still in the preliminary stage, there is much left to be discovered about D-aspartic acid.

Some people question if taking L-aspartic acid (the mirror-image of D-aspartic acid) offers the same boost to performance as its counterpart. However, these two forms of aspartic acid serve different purposes.

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“L” and “D” Forms Offer Different Benefits

All amino acids, except glycine, are considered “chiral molecules”, meaning they exist in two molecular forms that mirror each other. The L-form of aspartic acid is included in the 20 amino acids used as building blocks for protein. It is vital for proper formation of muscle tissue, skin, hair, and fingernails. It is also important for many key enzyme processes.[1]

On the other hand, D-aspartic acid is found in much smaller quantities inside the body. It accumulates in the pituitary gland, pineal gland, and testes. Its main role is to regulate hormone production, which makes it far more important for athletes than its L-isomer counterpart. Although it affects many hormones, most studies have observed its efficacy as a testosterone booster for male athletes.[1][2]

D-Aspartic Acid Benefits for Guys

D-aspartic acid is an important part of steroidogenesis, meaning it synthesizes steroid hormones such as testosterone. It regulates the release of luteinizing hormone, testosterone, and progesterone from the testes and pituitary gland.

D-Aspartic Acid Benefits for Men

One study shows test subjects increased testosterone by 42% when given 3.12 g D-aspartic acid for 12 days.[3][4][5]

The secretion of luteinizing hormone causes the hypothalamus to secrete human growth hormone. Raising growth hormone increases muscle and lean body mass. It also improves cardiac output and maximal exercise performance. In one study, increasing growth hormone was successful for raising VO2max (maximum capacity for transporting and using oxygen during exercise) from 78.9% to 96%.[6][7]

D-aspartic acid may also be a potent treatment for male infertility. After being produced in the testes, D-aspartic acid is secreted into venous blood. From here it passes into rete testis fluid and is incorporated into the spermatozoa once they leave the testis. Scientists noted men suffering from various kinds of infertility all had one thing in common: significantly decreased levels of D-aspartic acid in seminal fluid. Consequently, D-aspartic acid supplementation improves sperm health and function. However, more research is needed before it’s routinely used as an infertility treatment.[8][9]

Benefits for Ladies

D-aspartic acid’s influence on female anatomy has not been extensively studied. However, scientists discovered the female brain responds more strongly to this amino acid. One study dissected dorsal root ganglia neurons of male and female rats to determine any sex-based differences. Results show the female brain had a 2.8-fold larger density of NMDAR (N-methyl-D-aspartic acid receptors) when compared to the male brain.[10]

D-aspartic acid seems to also affect female sex hormones by decreasing testosterone and increasing estrogen. D-aspartic acid accumulates inside ovarian tissue. In the ovaries, excessive testosterone undergoes aromatase and is turned into estradiol, which is then synthesized into estrogen. While this is a natural process, D-aspartic acid greatly increases aromatase activity. In one study, female green frogs had 80% reduction in serum testosterone after D-aspartic acid supplementation.[11][12]

Increasing estrogen benefits overall feminine health, especially in older women undergoing menopause. Research shows estradiol increases spine density and synaptogenesis in the hippocampus. Females given D-aspartic acid had a 114.3% increase in dendritic spines, whereas male subjects exhibited no increase.[13]

Achieving Maximum Results from D-Aspartic Acid

Scientific Tools There is still much debate regarding proper dosing with D-aspartic acid. Most experts suggest keeping dosing between 1-3 g per day. A dose of 3.12 g daily has been used successfully in several studies without causing adverse effects.[2][14]

Related: See the Highest Rated D-Aspartic Acid Supplements on eSupplements.com

Recommendations differ when it comes to dosing schedule. Some experts suggest dosing for 4-12 weeks followed by a cessation period of 2-4 weeks. Others attest 90 days is the minimum amount of time to receive any effect. The rule of “12 on and 12 off” is the most popular recommendation for D-aspartic acid. This means supplementing for 12 days followed by a 12 day cessation period.[14][15]

However, other users say this recommendation is based on a single study that proved 12 days was effective, and doesn’t have enough merit to prove this is effective for everyone. Consequently, it is left up to personal preference to decide an ideal dosing schedule. This is why many people cling to the “12 on and 12 off” rule because it’s based on reliable scientific evidence.


[1] “The Differences Between L-Aspartic Acid and D-Aspartic Acid.” LiveStrong.com. Available from: http://www.livestrong.com/article/557557-the-differences-between-l-aspartic-acid-d-aspartic-acid/

[2] “The Effects of Aspartic Acid on Testosterone.” LiveStrong.com. Available from: http://www.livestrong.com/article/474566-the-effects-of-aspartic-acid-on-testosterone/

[3] Autimo D’Aniello, Anna Di Cosmo, Carlo Di Cristo, Lucio Annunziato, Leonard Petrucelli, George Fisher. “Involvement of D-aspartic acid in the synthesis of testosterone in rat testes.” Life Sciences. Volume 59, Issue 2, June 7 1996. Pages 97-104. Available from: http://www.sciencedirect.com/science/article/pii/0024320596002664

[4] Enza Topo, Andrea Soricelli, Antimo D’Aniello, Salvatore Ronsini, and Gemma D’Aniello. “Reproductive Biology and Endocrinology. October 27, 2009, 7:210. Available from: http://ww.biomedcentral.com/content/pdf/1477-7827-7-120.pdfStudien

[5] “Three Grams D-aspartic Acid Raises Testosterone Levels by Forty Percent.” Ergo-Log.com. Available from: http://www.ergo-log.com/dasparticacidtestosterone.html

[6] Antimo D’Aniello, M. Maddalena Di Fiore, Goerge H. Fisher, Alfredo Milone, Angelo Seleni, Salvatore D’Aniello, Alessandra F. Perna, and Diego Ingrosso. “Occurance 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.” The FASEB Journal. April 2000, Vol. 14 No. 5 pages 699-714. Available from: http://www.fasebj.org/content/14/5/699.short

[7] R.C. Cuneo, F. Salomon, C.M. Wiles, R. Hesp, and P.H. Sonksen. “Growth hormone treatment in growth hormone-deficient adults. II. Effects on exercise performance.” Journal of Applied Physiology. February 1, 1991, Vol. 70 No. 2, pages 695-700. Available from: http://jap.physiology.org/content/70/2/695.short

[8] Antimo D’Aniello, Maria Maddalena Di Fiore, Gemma D’Aniello, Frantz E. Collin, Giavonni Lewis, Brian P. Setchell. “Secretion of D-aspartic acid by the rat testis and its role in endocrinology of the testis and spermatogenesis.” FEBS Letters. Volume 436, Issue 1, September 25 1998, pages 23-27. Available from: http://www.sciencedirect.com/science/article/pii/S0014579398010874

[9] Gemma D’Aniello, M.D., Salvatore Ronsini, M.D., Francesco Guida, M.D., Patrizia Spinelli, Ph.D., Antimo D’Aniello, Ph.D. “Occurance of D-aspartic acid in human seminal plasma and spermatozoa: Possible role in reproduction.” Fertility and Sterility. Volume 84, Issue 5, November 2005, pages 1444-1449. Available from: http://www.sciencedirect.com/science/article/pii/S0015028205027172

[10] J.A. McRoberts, J. Li, H.S. Ennes, E.A. Mayer. “Sex-dependent differences in the activity and modulation of N-methyl-D-aspartic acid receptors in rat dorsal root ganglia neurons.” Neuroscience. Volume 148, Issue 4, September 2007, pages 1015-1020. Available from: http://www.sciencedirect.com/science/article/pii/S0306452207008755

[11] L Assisi, V Botte, A D’Aniello, and MM Di Fiore. “Enhancement of aromatase activity by D-aspartic acid in the ovary of the lizard Podarcis S. Sicula.” Reproduction, May 1, 2001; 121. Pages 803-808. Available from: http://www.reproduction-online.org/content/121/5/803.short

[12] MM Di Fiore, L Assisi, V Botte, and A D’Aniello. “D-aspartic acid is implicated in the control of testosterone production by the vertebrate gonad. Studies on the female green frog, Rana esculenta.” J Endocrinol May 1, 1998. 157; pages 199-207. Available form: http://joe.endocrinology-journals.org/content/157/2/199.short

[13] Romeo R.D., McCarthy J.B., Wang A., Milner T.A., EcEwan B.S. “Sex Differences in Hippocampal Estradiol-Induced N-methyl-D-aspartic Acid Binding and Ultrastructural Localization of Estrogen Receptor-Alpha.” Neuroendocrinology, 2005; 81: 391-399. Available from: http://www.karger.com/Article/FullText/89557

[14] “D-aspartic Acid.” Examine.com. Available from: http://examine.com/supplements/D-Aspartic+Acid/

[15] “D-aspartic acid dosing schedule?” AnabolicMinds.com. Available from: http://anabolicminds.com/forum/supplements/151008-d-aspartic-acid.html

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