3-hydroxybutyric acid is involved in the synthesis and degradation of ketone bodies. Like the other ketone bodies (acetoacetate and acetone) levels of beta-hydroxybutyrate are raised in the blood and urine in ketosis. Beta-hydroxybutyrate is a typical partial-degradation product of branched-chain amino acids (primarily valine) released from muscle for hepatic and renal gluconeogenesis.

Corynoxine B is a Beclin-1-dependent autophagy inducer. It is an natural alkaloid isolated from Uncaria rhynchophylla (Miq.) Jacks (Gouteng in Chinese).

Protirelin is a tripeptide that stimulates the release of thyrotropin and prolactin.