D-Aspartic Acid

Written by Carl Lombard

What is D-Aspartic Acid?

D-Aspartic acid (D-Asp) is an endogenous amino acid which has been found in the neuroendocrine tissues of both invertebrates and vertebrates. D-Asp was first found in the nervous system of marine mollusks and subsequently in the nervous and endocrine tissues of many other animals, including humans. High levels of D-Asp occur transiently in the brain of chickens, rats and humans during the last stage of embryonic life, suggesting that it has a role in the development of the nervous system. In addition, within the nervous system this amino acid is concentrated in the axon terminals (synaptosomes) and in synaptic vesicles together with L-Asp and L-Glu; additionally, it is involved in visual activity, suggesting it has a role in neurotransmission.


Effect of D-Aspartic Acid Supplementation

“D-aspartic acid has been suggested to enhance athletic performance by regulating the hypothalamus-pituitary-gonadal axis by increasing plasma testosterone. Aspartate supplementation may be useful to increase testosterone for individuals with low plasma testosterone due to aging and other conditions.”

Here’s a study to determine the effect of D-aspartic acid supplementation on athletic performance in young male athletes –

After screening for ACSM low risk, 9 healthy male athletes (average age = 22y, body weight = 82.7 kg and body fat = 10.4%) were randomized to two groups for supplementation using a double blinded parallel arm experimental design. They ingested either 3 grams of d-aspartic acid (Aspartate, n=5) or a Placebo (n=4) for 14 days supplied in capsule form. Subjects recorded and replicated previous 3 day diets prior to testing. Physical assessments were performed prior to and after supplementation included a peak VO2 test by cycle ergometer, 1 maximal repetition bench press and 1 maximal repetition squat (average values ±SD before supplementation were 41.7 ±6.4 ml/kg/min, 117.9 ±11.1 kg and 151.7 ±19.0 kg, respectively).

Results: The Aspartate group improved performance in 1 maximal repetition bench press by 4.5 ±1.6kg (average ±SEM, p=0.03) and 1 maximal repetition squat by 8.2 ±3.8kg (average ±SEM, p=0.04). No change in performance measures were observed in the Placebo group. Body composition did not change for either group.

“D-aspartic acid supplementation may lead to improved acute skeletal muscle synthesis improving upper and lower body muscle performance.”

“D-Aspartic acid (d-Asp), an endogenous amino acid present in vertebrates and invertebrates, plays an important role in the neuroendocrine system, as well as in the development of the nervous system.”

“Recently, d-aspartic acid (d-Asp) has been suggested as being involved in mechanisms regulating reproduction activity in animals and human.”

“DAA holds the potential to be an effective testosterone booster, available as a [testosterone] supplement. It appears to satisfy the criteria to be considered a DSHEA-eligible candidate, being an endogenous bio-molecule, and present in common food products.”



“DAA increases the levels of prolactin which can impair libido and erectile function), and GH (growthhormone). The increase of prolactin does not appear to be a real issue, and DAA has been shown toincrease GH; therefore, theoretically no problem should arise from this either.”

“DAA also increases vasopressin and oxytocin, these increased hormones can lead to hyponatremia;therefore, consuming the sodium D-aspartate may help to blunt this effect.”



From Wikipedia

“Aspartic acid (abbreviated as Asp or D; encoded by the codons [GAU and GAC]), also known as aspartate, is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group, an α-carboxylic acid group (which is in the deprotonated −COO− form under biological conditions), and a side chain CH2COOH. Under physiological conditions in proteins the sidechain usually occurs as the negatively charged aspartate form, −COO−. It is semi-essential in humans, meaning the body can synthesize it from oxaloacetate.”



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Carl Lombard

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