Humans are always striving to improve their health, seeking out ways to optimize outcomes. This idea of biohacking has become so ingrained in how we live that it often goes unnoticed. Aspartic acid is one such non-essential amino acid found in two forms: L and D-aspartic acid. Studies suggest that the latter may have a role to play in testosterone synthesis and even increasing human growth hormone, both associated with greater libido and improved quality of life. We’ll be looking into the research of D-aspartic acid and digging deep to find out if its claims truly hold up to scrutiny.
D-aspartic Acid: What Is It?
Research shows that D-aspartic acid (DAA) supplementation can affect the hypothalamic-pituitary-gonadal axis (HPG), a non-essential amino acid found in the central nervous system and reproductive tissues. Animals produce more testosterone as well as more luteinizing hormone when DAA accumulates at this site.
D-aspartic Acid: How Does It Work?
L-aspartic acid and D-aspartic acid are naturally occurring forms of aspartic acid. Both can be synthesized by the body and obtained through protein sources.
D-aspartic acid is found in synapses and neurons of the brain. With its molecular structure closely resembling neurotransmitter N-methyl-D-aspartate (NMDA), it can bind to NMDA receptors, similarly acting as a neurotransmitter. Additionally, studies in vitro, or in animal models, have explored its effects on neuroendocrine function of the hypothalamus and pituitary gland, resulting in secretion of hormones such as gonadotropin-releasing hormone, prolactin, luteinizing hormone and human growth hormone, as well as affecting testosterone. Although much remains unknown about DAA’s mechanisms and relevance to humans due to inconclusive research results.
Benefits of D-aspartic Acid
Testosterone levels may be improved
A significant amount of research has looked into the influence of D-aspartic acid on testosterone production. While studies done on rodents indicate it may elevate levels of testosterone, there is scant confirmation that it has a similar impact on human growth hormone in humans. Despite this lack of substantiating evidence, D-aspartic acid continues to be promoted as effective for increasing strength and building muscle with resistance exercises. Unfortunately, the available data does not back up these assertions.
After 30 days of supplementation, 3g of DAA supplementation increased total testosterone by 42% among untrained participants. However, after 30 days of supplementation, there were no elicited changes in resistance trained men. Additionally, researchers found that a higher dose of 6g per day reduced testosterone by 12.5%, suggesting a deleterious effect on the HPG axis’ negative feedback mechanisms.
Fertility may be increased by this drug
Despite inconsistent outcomes in other treatments, research suggests that D-aspartic acid could be a beneficial tool for male fertility. A study of 30 infertile men revealed that taking a daily dose of sodium D-aspartate over 90 days led to positive changes in spermatozoa concentration and motility, along with pregnancies among their partners. Results showed a notable improvement due to supplementation with aspartate [R].
Strengthens the body
The PLoS One study investigated the effects of DAA supplementation by assessing parameters such as basal hormones and isometric strength over three months. Results revealed an increase in isometric strength and free muscle mass in both groups, but no difference between them when it came to testosterone or free testosterone. This suggests that DAA has no influence on muscle strength or improved resistance training measures.
Participants in another study who supplemented with D-aspartic acid and participated in resistance training for 28 days experienced a 2.9-pound (1.3-kg) increase in lean mass. Those in the placebo group, however, experienced a similar increase of 3 pounds (1.4 kg) [R].
Dosage of D-aspartic Acid
D-aspartic acid should be taken daily in doses between 2,000 – 3,000mg.
Takeaway: D-aspartic Acid
Ultimately, there isn’t enough evidence to support D-aspartic acid’s ability to increase free and total testosterone, or to improve quality of life indicators.
Since so many different supplements are available, it is important to research which natural testosterone boosters are effective. Although preliminary studies suggest that 3g of D-aspartic acid, did have a positive effect on tesosterone levels, every study following has shown no increase, or even a negative effect.
Nevertheless, there is some evidence that D-aspartic acid can benefit sperm quality and quantity in men experiencing fertility problems. Therefore, more research is needed to confirm if DAA is a possible therapy for infertility and low testosterone.