HGH Fragment 176-191

AOD-9604 is a synthetic fragment of human growth hormone: residues 177 to 191 of the hormone with an extra tyrosine added at the front, 16 amino acids in total. 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, development stopped after its big Phase IIb trial missed its weight-loss target, and it is banned in sport by WADA.

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.

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.

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.

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.

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.