Lactic acid is a chemical compound that plays a role in various biochemical processes. Lactic acid is a carboxylic acid with the chemical formula C3H6O3. It has a hydroxyl group adjacent to the carboxyl group, making it an alpha hydroxy acid (AHA).Lactic acid is miscible with water or ethanol, and is hygroscopic. Lactic acid is chiral and has two optical isomers. In animals, L-lactate is constantly produced from pyruvate via the enzyme lactate dehydrogenase (LDH) in a process of fermentation during normal metabolism and exercise. It does not increase in concentration until the rate of lactate production exceeds the rate of lactate removal, which is governed by a number of factors, including monocarboxylate transporters, concentration and isoform of LDH, and oxidative capacity of tissues. Lactic acid is also employed in pharmaceutical technology to produce water-soluble lactates from otherwise insoluble active ingredients.