Glossary
Agonist
A molecule that binds a receptor and activates it, mimicking the natural signal. Semaglutide, for example, is a GLP-1 receptor agonist.
Relevant compounds
- Semaglutide
Long-acting GLP-1 receptor agonist
- Tirzepatide
Dual GIP and GLP-1 receptor agonist
- Retatrutide
Investigational GIP, GLP-1 and glucagon triple agonist
- PT-141
Cyclic melanocortin-receptor agonist
- Melanotan II
Non-selective cyclic melanocortin agonist
- CJC-1295
GHRH analogue
- Ipamorelin
Selective ghrelin-receptor agonist
- Liraglutide
First-generation acylated GLP-1 receptor agonist
- Cagrilintide
Long-acting amylin and calcitonin receptor agonist
- Tesamorelin
Stabilised full-length GHRH analogue
- GHRP-6
First-generation ghrelin-receptor agonist
- IGF-1 LR3
Long-acting IGF-1 analogue used in cell culture
Further reading
- Semaglutide vs tirzepatide vs retatrutide: the three incretin peptides compared
How the three best-known incretin research compounds differ in receptor targets, evidence and regulatory status, with links to each head-to-head comparison.
- Incretin and amylin peptides explained: GLP-1, GIP, glucagon and amylin
A plain-English map of the receptors behind semaglutide, tirzepatide, retatrutide, cagrilintide and the earlier GLP-1 analogues, and how each added a target.
- The melanocortin system explained: MC1R to MC5R
A guide to the five melanocortin receptors and the compounds studied at each, from afamelanotide and melanotan II to PT-141 and setmelanotide.