What are peptides
actually good for?

Sold alongside peptides as a fat-loss compound, though it is a small molecule, not a peptide. It blocks the enzyme NNMT and reduces obesity in mice. No human efficacy or safety data has been published.

A modified fragment of human growth hormone, built to trigger fat burning without growth hormone's other effects. Sold today for fat loss and joint repair; its pivotal obesity trial failed to establish meaningful weight loss and development was discontinued.

The most-searched peptide for tendon, ligament and gut healing. Consistent, striking results across many animal studies; no completed human trial yet.

A long-acting amylin analog from Novo Nordisk, tested mostly in combination with semaglutide as CagriSema. The combination produced over 20% weight loss in a 3,417-person Phase 3 trial; on its own, cagrilintide performed less well than semaglutide alone. It is investigational and not approved.

A growth-hormone-releasing hormone analog, usually stacked with ipamorelin. It raises growth hormone and IGF-1 durably in human study, though the muscle and anti-aging uses it is sold for have no human evidence. Clinical development was abandoned after a participant death.

A nine-amino-acid peptide isolated from rabbit blood in 1977 and named for what it was hoped to do. Human sleep studies exist but total fewer than 40 patients across four decades and contradict each other, and a 2006 review notes its gene, protein and receptor have never been isolated.