Weight Loss Peptides

Also: Ozempic, Wegovy

Semaglutide is a GLP-1 receptor agonist, a peptide engineered to mimic the natural gut hormone GLP-1 but with a roughly week-long half-life so it can be dosed once weekly. It is FDA-approved and sold as Ozempic and Rybelsus for type 2 diabetes and as Wegovy for chronic weight management, with cardiovascular benefit also on the label. This is one of the most rigorously tested peptides in existence, backed by large randomized trials, so the evidence here is in a completely different league from research-only peptides.

Also: Mounjaro, Zepbound

Tirzepatide is a single peptide that activates two receptors at once: GIP and GLP-1, the two main incretin hormones your gut releases after eating. It is FDA-approved as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management and obstructive sleep apnea, and it has produced the largest weight-loss numbers of any approved drug to date. Like semaglutide, this is a heavily trialed, fully approved medicine, not a gray-market research compound.

Also: Anti-Obesity Drug 9604, Tyr-hGH Fragment 177-191

AOD-9604 is a synthetic fragment of human growth hormone, copying just the last 15 amino acids of the hormone (residues 176 to 191) plus a tyrosine cap. The idea was to keep the fat-burning end of growth hormone while leaving out the part that raises IGF-1 or messes with blood sugar. It was developed by Metabolic Pharmaceuticals in Australia and tested as an anti-obesity drug, but it is not approved by the FDA or any major regulator, and development stopped after it missed its weight-loss targets.

Also: LY3437943, Triple G

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 a phase 2 trial it produced some of the largest weight loss ever recorded for a drug, up to roughly 24 percent of body weight at the top dose. It is investigational, made by Eli Lilly, and not yet FDA approved as of 2026.

Also: Frag 176-191, HGH Frag

HGH Fragment 176-191 is exactly what it sounds like: a short tail-end piece of the human growth hormone molecule, amino acids 176 through 191. The idea was to keep the fat-burning part of growth hormone while ditching the parts that raise blood sugar and IGF-1. The optimized drug version, AOD-9604, actually went through real human trials for obesity, and the blunt result is that it was very safe but did not produce meaningful weight loss.

Also: Victoza, Saxenda

Liraglutide is a once-daily injectable GLP-1 receptor agonist, a synthetic peptide that shares about 97% of its sequence with the natural gut hormone GLP-1 but is engineered with a fatty acid chain so it survives in the body far longer. It is FDA-approved as Victoza for type 2 diabetes (2010) and as Saxenda for chronic weight management (2014), and is one of the most studied drugs in its class. As of 2024 a generic version is also FDA-approved.

Also: Trulicity

Dulaglutide (brand name Trulicity) is a once-weekly injectable GLP-1 receptor agonist made by fusing a modified GLP-1 peptide to a fragment of a human antibody, which is what lets it last a full week between shots. It is FDA-approved for type 2 diabetes and, notably, to reduce cardiovascular risk in adults with diabetes. The once-weekly dosing made it a major convenience step up from earlier daily and twice-daily agents.

Also: Byetta, Bydureon

Exenatide is the original GLP-1 receptor agonist and it came from an unlikely source: the saliva of the Gila monster, a venomous desert lizard. It is a synthetic 39-amino-acid peptide (a copy of the natural exendin-4) sharing about 50% of its sequence with human GLP-1, sold as the twice-daily Byetta (FDA-approved 2005) and the once-weekly Bydureon. It was the first drug to successfully turn the short-lived incretin hormone into a real diabetes therapy.

Also: BI 456906

Survodutide is an injectable dual agonist that hits both the GLP-1 and glucagon receptors, developed by Boehringer Ingelheim and Zealand Pharma. 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 mid-2026.

Also: LY3502970, OWL833

Orforglipron is Eli Lilly's oral, once-daily GLP-1 receptor agonist, and the headline is that it is a small molecule, not a peptide, so it survives the gut and can be taken as a plain pill with no food or water restrictions. It is being developed for type 2 diabetes and obesity and has completed multiple successful Phase 3 trials. As of mid-2026 it is filed for regulatory review but not yet approved.

Also: Rybelsus

Oral semaglutide is the pill version of the same GLP-1 peptide found in Ozempic and Wegovy, sold for type 2 diabetes as Rybelsus. The trick that makes it work is an absorption enhancer called SNAC, which shields the peptide from stomach acid and helps it cross the gut lining. Lower doses are approved for diabetes, and higher 25 mg doses have now been approved as the first GLP-1 pill for weight loss.

Also: Imcivree, RM-493

Setmelanotide (brand name Imcivree) is a melanocortin-4 receptor (MC4R) agonist peptide and a genuine FDA-approved obesity drug, first cleared in 2020. It is not a general weight-loss shot like the GLP-1 drugs: it is a targeted therapy for rare genetic forms of severe obesity where a specific brain hunger circuit is broken. It is given as a once-daily subcutaneous injection and has since been approved for additional conditions including Bardet-Biedl syndrome and acquired hypothalamic obesity.

Also: Semaglutide + Cagrilintide

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.

Also: 5-amino-1-methylquinolinium, NNMT Inhibitor

First, a correction worth making loudly: 5-amino-1MQ is not a peptide. It is a small molecule (5-amino-1-methylquinolinium), and it gets lumped in with research peptides mostly because of the crowd that sells it. It blocks an enzyme called NNMT, and in obese mice it produced weight and fat loss without the animals eating less. No human trials have been published.

Also: AM833, NN9838

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.

Also: GSBR-1290, Structure GSBR-1290

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.