Beta-Hydroxyisovaleric acid (also known as 3-hydroxyisovaleric acid or 3HIA) is a normal human metabolite excreted in the urine. It is a byproduct of the leucine degradation pathway. Beta-Hydroxyisovaleric acid serves as a sensitive indicator of marginal biotin deficiency in humans. The variability of the proportion of leucine catabolites excreted as 3HIA suggests substantial population heterogeneity in the metabolic capacity of the 3HIA-carnitine detoxification pathway. In addition, was shown that in type II diabetic patients the catabolism of leucine was accelerated even in the absence of ketosis and that the urinary beta-hydroxyisovaleric acid concentration was a useful marker of short-term metabolic control in these patients.

4-Amino-3-hydroxybutanoic acid (GABOB) is an endogenous ligand found in the central nervous system in mammals. γ-Amino-β-hydroxybutyric acid is a derivative of the neurotransmitter GABA. It has been claimed to be of value in neurological disorders and to have an antihypertensive effect. γ-Amino-β-hydroxybutyric acid can help overcome stress and anxiety, improve learning and boost memory function. It is also known to increase growth hormone levels, which help the body heal and rejuvenate itself. There are no reported side effects of γ-Amino-β-hydroxybutyric acid when taken at therapeutic dosages. At high dosages, some slight drowsiness may occur. Adverse effects have included dizziness and anorexia also.