Supplement Monograph
L-Aspartic Acid
L-Aspartic acid is a nonessential amino acid involved in the urea cycle, the TCA cycle, nucleotide synthesis and neurotransmission.
What Is L-Aspartic Acid?
L-Aspartic acid (aspartate) is a nonessential, acidic amino acid that sits at several metabolic crossroads — the urea cycle, energy metabolism and nucleotide synthesis — and acts as an excitatory neurotransmitter. Its negatively charged side chain is common in enzyme active sites.
Role in the Body
Aspartate donates nitrogen to the urea cycle, feeds the TCA (citric acid) cycle as oxaloacetate, and provides backbone atoms for making purine and pyrimidine nucleotides (DNA and RNA). In the nervous system it acts as an excitatory transmitter. The related molecule D-aspartate has signalling roles in the brain and reproductive tissues, and D-aspartic acid is marketed as a testosterone-support supplement with mixed evidence.
As a Supplement
Aspartate salts are used as mineral carriers (e.g. magnesium or potassium aspartate), and D-aspartic acid is sold for hormonal support. Standalone L-aspartic acid supplementation is otherwise uncommon.
Dosage & Safety
Aspartic acid is supplied by dietary protein and made by the body. It is well tolerated as a food component. Supplemental limits, interactions and pregnancy safety are pending the detailed research buildout.
General overview — detailed clinical evidence and citations pending full research buildout.