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 hypothalamo-pituitary-gonadal axis in resistance-trained men

Nutr Res. 2013 Oct;33(10):803-10. doi: 10.1016/j.nutres.2013.07.010. Epub 2013 Aug 15.


It was hypothesized that D-aspartic acid (D-ASP) supplementation would not increase endogenous testosterone levels or improve muscular performance associated with resistance training. Therefore, body composition, muscle strength, and serum hormone levels associated with the hypothalamo-pituitary-gonadal axis were studied after 28 days of resistance training and D-ASP supplementation. Resistance-trained men resistance trained 4 times/wk for 28 days while orally ingesting either 3 g of placebo or 3 g of D-ASP. Data were analyzed with 2 × 2 analysis of variance (P < .05). Before and after resistance training and supplementation, body composition and muscle strength, serum gonadal hormones, and serum D-ASP and d-aspartate oxidase (DDO) were determined. Body composition and muscle strength were significantly increased in both groups in response to resistance training (P < .05) but not different from one another (P > .05). Total and free testosterone, luteinizing hormone, gonadotropin-releasing hormone, and estradiol were unchanged with resistance training and D-ASP supplementation (P > .05). For serum D-ASP and DDO, D-ASP resulted in a slight increase compared with baseline levels (P > .05). For the D-ASP group, the levels of serum DDO were significantly increased compared with placebo (P < .05). The gonadal hormones were unaffected by 28 days of D-ASP supplementation and not associated with the observed increases in muscle strength and mass. Therefore, at the dose provided, D-ASP supplementation is ineffective in up-regulating the activity of the hypothalamo-pituitary-gonadal axis and has no anabolic or ergogenic effects in skeletal muscle.

Keywords: 1 repetition maximum; 1-RM; BSA; D-ASP; DDO; ELISA; Estradiol; GnRH; H(2)O(2); HCL; HPG axis; LH; Luteinizing hormone; N-methyl d-aspartic acid; NMDA; Resistance training; Testosterone; bovine serum albumin; d-Aspartic acid; d-aspartate oxidase; d-aspartic acid; enzyme-linked immunoabsorbent assay; gonadotropin-releasing hormone; hydrochloric acid; hydrogen peroxide; hypothalamo-pituitary-gonadal axis; luteinizing hormone.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Analysis of Variance
  • Body Composition / drug effects*
  • D-Aspartic Acid / pharmacology*
  • Dietary Supplements*
  • Estradiol / blood
  • Gonadotropin-Releasing Hormone / blood
  • Hormones / blood*
  • Humans
  • Luteinizing Hormone / blood
  • Male
  • Muscle Strength / drug effects*
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / physiology
  • Resistance Training*
  • Testosterone / blood
  • Young Adult


  • Hormones
  • Gonadotropin-Releasing Hormone
  • Testosterone
  • D-Aspartic Acid
  • Estradiol
  • Luteinizing Hormone