Receptor / Agonist
Also known as: agonist · antagonist · receptor binding · ligand
A receptor is a cell’s signal-receiving protein; an agonist binds it and activates it, an antagonist blocks it.
A receptor is a protein — usually on a cell’s surface — that recognises and binds a specific signalling molecule (a ligand) and, in response, triggers a change inside the cell. Receptors are how peptides exert most of their effects.
A molecule that binds a receptor and switches it on is an agonist; one that binds without activating, blocking the natural signal, is an antagonist. Many research peptides are studied precisely for being selective agonists at a particular receptor.
Selectivity — hitting the intended receptor and few others — is a major research goal, because it is what separates a clean effect from off-target ones.
RELATED TERMS
Secretagogue
A substance that prompts a gland to secrete a hormone — e.g. a GH secretagogue triggers the pituitary to release growth hormone.
GHRH
Growth-Hormone-Releasing Hormone — the hypothalamic hormone that signals the pituitary to release growth hormone.
GHRP
Growth Hormone Releasing Peptide — a class acting on the ghrelin receptor to trigger pulsatile GH release.
Analog
A peptide deliberately modified from a natural sequence to improve stability, selectivity or potency.
Educational content, not medical advice. All products supplied for research purposes only — not for human consumption.