Receptor

Last updated August 2026

A protein, usually on a cell surface, that a peptide or hormone binds to in order to trigger an effect. Which receptor a peptide targets largely defines what it does.

A receptor's shape is highly specific, so a peptide that fits the GLP-1 receptor may do nothing at a melanocortin receptor. Some compounds are deliberately built to hit more than one target, such as dual agonists that engage both GIP and GLP-1 receptors. Repeated heavy stimulation can prompt cells to reduce their receptor count, a phenomenon behind discussions of downregulation and dose breaks.

Educational reference only — not medical advice. Always follow the guidance of a qualified healthcare professional.