Tirzepatide Alternatives

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.

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.

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.

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.

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.

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.

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.

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.