D-aspartic acid (D-Asp)

D-aspartic acid (D-Asp) is an endogenous d-amino acid that functions as a crucial signaling molecule in the mammalian central nervous system and endocrine system [1, 4]. Unlike its L-enantiomer, D-Asp is not incorporated into proteins but acts as a neurotransmitter and neuromodulator, primarily by serving as an agonist at the N-methyl-D-aspartate (NMDA) receptor and the metabotropic glutamate receptor 5 (mGluR5) [3]. It is found in high concentrations within the pituitary gland and testes, where it plays a fundamental role in the regulation of the hypothalamic-pituitary-gonadal (HPG) axis by stimulating the release of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and testosterone [2, 4]. In a clinical context, D-aspartic acid is not typically categorized as a direct therapeutic target (such as an enzyme or receptor) but is instead utilized as a therapeutic agent and a potential biomarker for reproductive health. It is commonly marketed as a dietary supplement intended to treat male infertility and enhance athletic performance by boosting testosterone levels, though clinical results in healthy populations remain inconsistent [2]. Research also investigates the role of D-Asp in neuropsychiatric disorders like schizophrenia, as its regulation by the enzyme D-aspartate oxidase is vital for maintaining proper NMDA receptor-mediated signaling [3]. Notable safety considerations include the potential for NMDA-mediated excitotoxicity at high concentrations and the impact of exogenous supplementation on systemic hormonal homeostasis.

Other names

D-aspartate(R)-2-Aminobutanedioic acid(2R)-2-Aminobutanedioic acid(D)-Aspartic acidDAA

Agonism of the N-methyl-D-aspartate (NMDA) receptor and stimulation of the hypothalamic-pituitary-gonadal (HPG) axis via the promotion of GnRH and LH secretion, leading to increased testosterone synthesis.