Phenyl acetate (or phenylacetate) is a carboxylic acid ester that has been found in the biofluids of patients with nephritis and/or hepatitis as well as patients with phenylketonuria (PKU) an inborn error of metabolism. Excess phenylalanine in the body can be disposed of through a transamination process leading to the production of phenylpyruvate.

(R)-(-)-1,3-Butanediol is a novel ketogenic ester that rapidly elevates circulating r- and s-?-hydroxybutyric acid levels in healthy adults, making it useful for studying metabolic system-related diseases.

Cholesteryl oleate is a cholesteryl ester. Cholesteryl oleate can be used to synthesize solid lipid nanoparticles which is a nanoparticle-based gene therapy approach.