# AOD-9604: The hGH C-Terminal Fragment 176-191, Read From the Literature > AOD-9604 is the C-terminal lipolytic fragment of human growth hormone. It cuts fat synthesis in rodents, spares the GH receptor, and missed its weight-loss endpoint in humans. A cited digest. A digest of the published record: the antilipogenic mechanism, the doses studied by species and route, and the obesity trial that did not beat placebo. Every number cited. ## The short version AOD-9604 is a small lab-made peptide. It copies one part of human growth hormone — the tail end, called the [hGH fragment 176-191](/hgh-fragment-176-191) — that the body uses to handle fat. In fat cells it slows the building of new fat (this is called being antilipogenic) and nudges cells to burn a bit more fat. Here is the part the ads skip: it does this without acting like growth hormone itself. It does not switch on the growth hormone receptor (the cell's docking port for the full hormone), so it does not raise IGF-1 (a growth signal) and does not cause growth-hormone-style side effects. It was built to be a weight-loss drug. In mice it worked. In people it did not — the main human obesity trial showed no real weight loss versus a dummy pill, and the program was dropped. Most of the good data is still in animals. It is not FDA-approved, not a supplement, and banned in sport. What people report — including the downsides and the fat loss that often never comes — is on [the effects page](/effects). ## What the AOD-9604 literature actually shows AOD-9604 was engineered to reproduce the fat-metabolising activity of growth hormone's C-terminal domain while leaving the rest of the hormone behind. The design works at the receptor level: it does not bind the growth hormone receptor and does not raise circulating IGF-1 [1]. That is the whole point of the molecule — fat effects without growth signalling. In fat tissue, the mechanism is mostly antilipogenic. The C-terminal sequence inhibits acetyl-CoA carboxylase (the rate-limiting enzyme that builds new fatty acids) through a membrane-derived second messenger, cutting de novo fat synthesis [2]. The synthetic 177-191 sequence showed antilipogenic activity identical to intact hGH, with no significant lipolytic effect measured by glycerol release from rat fat pads [3]. The popular framing — a direct fat-burning peptide — runs ahead of that data. In obese mice, 14 days of chronic dosing reduced body weight and fat and raised beta-3 adrenergic receptor expression (a fat-cell switch for burning fat); in mice lacking that receptor, the long-term weight effect disappeared [4]. The rodent record is consistent and reproducible. Then the human chapter. Across roughly six trials totalling about 900 obese adults, oral AOD-9604 was as safe and tolerable as placebo [5] — but the pivotal Phase IIb trial did not show statistically significant weight loss versus placebo, and the obesity program was discontinued around 2007 [9]. The honest headline is a negative result. ## AOD-9604: fragment, not hormone AOD-9604 is a 16-amino-acid peptide — a hexadecapeptide — modelled on hGH residues 177-191 with a tyrosine added at the front in place of the native phenylalanine [3]. Two cysteines form a disulfide bridge that mirrors the loop in the parent hormone. It is a fragment, not growth hormone, and not a growth-hormone secretagogue: it does not signal the pituitary to release more hormone the way CJC-1295, ipamorelin, or sermorelin do. That distinction is the spine of the molecule's identity, and it runs through the [AOD-9604 research](/research) summarised here. Reported sequence: Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe. Molecular formula C78H123N23O23S2; molecular weight about 1815.1 Da; CAS 221231-10-3. ## Status of record Not FDA-approved for any indication. Not a dietary supplement. Developed by Metabolic Pharmaceuticals as an oral anti-obesity drug; program discontinued after the pivotal trial missed its endpoint [9]. Prohibited in sport: as a growth-hormone fragment, AOD-9604 falls under the WADA Prohibited List, Section S2 (peptide hormones and their fragments), and is prohibited at all times [6]. Reviewed by the FDA Pharmacy Compounding Advisory Committee in December 2024; current 503A status should be checked independently. This site documents that record and nothing else. It is editorial commentary on published science — see the [AOD-9604 references](/references). It does not sell anything and gives no medical advice. --- A brushed-steel worksheet on the AOD-9604 record — the antilipogenic fragment logged first, the receptor-sparing design stated as the design it is, and the failed human weight-loss trial left in plain steel; no clinic behind the console and nothing here dosed, compounded, prescribed, or sold.