Best Peptides for Weight Loss

Retatrutide is the heavy hitter of the new weight-loss drugs: a once-weekly injectable peptide that hits three receptors at once - GIP, GLP-1, and glucagon - earning it the nickname triple-G agonist. In phase 2 it produced about 24 percent weight loss at the top dose, and in the phase 3 TRIUMPH-1 trial Lilly reported 28.3 percent at 12 mg over 80 weeks. It is investigational, made by Eli Lilly, and not FDA approved; Lilly plans to file with the FDA in the first quarter of 2027. Because it is not an approved drug, FDA says it cannot be legally compounded.

Survodutide is an injectable dual agonist that hits both the GLP-1 and glucagon receptors, discovered by Zealand Pharma and developed by Boehringer Ingelheim. It is being tested for obesity and for fatty liver disease (MASH), and it carries an FDA Breakthrough Therapy designation for MASH. It is still investigational and not approved for any use as of October 2026, and no US filing has been publicly announced.

CagriSema is a once-weekly injectable that pairs two drugs in one shot: semaglutide (a GLP-1 receptor agonist, the molecule behind Ozempic and Wegovy) and cagrilintide (a long-acting amylin analog). It is being developed by Novo Nordisk for obesity and type 2 diabetes, and in 2025 it cleared its phase 3 REDEFINE trials. It is not yet approved by the FDA, though regulatory filings are underway.

Cagrilintide (also called AM833) is a long-acting synthetic analog of amylin, the gut-brain satiety hormone co-secreted with insulin by pancreatic beta cells. It is an investigational once-weekly injectable being developed by Novo Nordisk for obesity, most prominently as the amylin half of CagriSema (cagrilintide plus semaglutide). It is not yet approved as a standalone drug, but it has cleared phase 2 trials and is in late-stage development.

Eloralintide (Eli Lilly code LY3841136) is an investigational, long-acting, selective amylin receptor agonist given as a once-weekly subcutaneous injection for obesity. Amylin is the satiety hormone your pancreas releases alongside insulin, and eloralintide is built to mimic it without the gut side effects that sink most appetite drugs. It is not approved anywhere yet, but it has cleared Phase 1 and a 263-person Phase 2 trial with weight loss up to roughly 20 percent, and Lilly has said it is moving into Phase 3.

Mazdutide is a GLP-1 and glucagon dual agonist, which puts it between semaglutide (GLP-1 only) and retatrutide (GLP-1, GIP and glucagon). It is built on oxyntomodulin, a natural gut hormone that hits both receptors, rather than on a GLP-1 backbone. It is furthest along in China, where it is approved for both weight management and type 2 diabetes. Western approval has not happened.

NA-931 (Bioglutide) is cyclic glycine-proline, a two-amino-acid ring that occurs naturally as a breakdown product of IGF-1. Its developer, Biomed Industries, describes it as an oral once-daily agonist at four receptors at once - IGF-1, GLP-1, GIP and glucagon - and has reported 13 to 15 percent weight loss in a 126-person Phase 2 trial. Those numbers have only ever appeared in conference abstracts, never in a peer-reviewed paper, and no trial results have been filed to ClinicalTrials.gov. The same molecule is already sold as a consumer brain-health supplement and as a Sigma-Aldrich catalogue chemical, which makes it unusually cheap to source and unusually hard to verify.

Adipotide is an experimental peptide built to kill fat tissue by cutting off its blood supply. One half homes in on prohibitin, a protein on the blood vessels that feed white fat, and the other half is a cell-killing sequence that triggers those vessel cells to self-destruct. It produced striking weight loss in obese mice and monkeys, but it also caused kidney damage in every primate species tested, and its only human trial was terminated after enrolling 4 people with no results ever posted.