Catalogues group compounds by the biology researchers usually study. Below is what each family means in plain English. Evidence strength varies — preclinical only for many repair peptides; large human trials for some metabolic ones.
Metabolic & weight-regulation peptides
Mimic gut hormones (GLP-1, GIP, amylin) or related pathways. Studied for blood sugar, appetite, gastric emptying, and body-weight endpoints in trials. Examples in the literature: semaglutide, cagrilintide. Some are approved medicines; catalogue analogues are research materials only.
GH axis — growth-hormone signalling
Two main tool types: GHRH analogues (stimulate the pituitary via one receptor) and GHRP/ghrelin-mimetics (another receptor). Together they are studied for pulsatile GH and downstream IGF-1 in endocrine research. Examples: ipamorelin, CJC-1295, sermorelin, tesamorelin (FDA-approved for a specific HIV-related indication).
Repair & soft-tissue peptides
Studied in tendon, ligament, gut, and wound models — mostly rodent and cell data. BPC-157 and thymosin β4 (TB-500) are the common names here. Human clinical evidence is limited; treat claims as hypotheses until primary papers say otherwise.
Cosmetic & copper peptides
GHK-Cu and similar copper tripeptides appear in skin remodelling, wound, and gene-expression research. Separate cosmetic marketing from peer-reviewed experimental work.
Immune, mitochondrial, nootropic, melanocortin
- Immune (e.g. thymosin α1, LL-37) — immune-cell signalling and host-defence models.
- Mitochondrial (e.g. MOTS-c, SS-31 / elamipretide) — energy metabolism and organelle function research.
- Nootropic (e.g. Semax, Selank) — neurotrophic and behaviour endpoints in experimental literature.
- Melanocortin (e.g. PT-141 / bremelanotide) — receptor biology; one product has FDA approval for a labelled indication.
Families help you choose what to read — they do not mean every compound in a class is safe, effective, or legal for your use case. Always match the specific molecule to primary evidence.