D-Asp has shown promise in improving sperm quality and fertility rates in men, though results for muscle building are generally inconclusive.
The most common form, L-Asp is a "proteinogenic" amino acid used to build enzymes and tissues. It is central to the urea cycle , helping the liver detoxify ammonia, and plays a key role in the malate-aspartate shuttle , which helps cells generate energy (ATP). aspartic acid
While naturally produced by the body, aspartic acid is popular as a dietary supplement: D-Asp has shown promise in improving sperm quality