At a glance

What is AOD-9604?

AOD-9604 is a synthetic peptide based on the C-terminal (tail) region of human growth hormone, with an added amino acid to stabilize it. The name stands for "Advanced Obesity Drug," reflecting its original development by Metabolic Pharmaceuticals as a weight-loss candidate. It is sold on the wellness and "research peptide" market for fat loss, often under the broader "hGH fragment 176-191" label, though it is a modified version of that fragment rather than the bare fragment.

How does it work?

The proposed idea is that the tail region of growth hormone carries its fat-burning activity without the rest of the hormone's effects. In animal and cell studies, AOD-9604 increased both fat breakdown and fat oxidation while it reduced fat storage, reportedly without activating the growth hormone receptor or causing growth or insulin-resistance effects. In rodents, it also raised markers of fat metabolism (here¹ and here²). These are animal and laboratory findings; the human trials below tested whether they translate.

Is it FDA-approved?

No. AOD-9604's regulatory status covers several points:

• Not approved by the FDA for any use, and never reached market as a drug
• A history that includes an attempt to position it as a food/supplement ingredient
• Not an approved compounding substance
• Prohibited at all times in sport under the WADA list, which covers growth hormone fragments including AOD-9604

What does the research show?

Unusually for a wellness peptide, AOD-9604 was tested in real human trials, and they were negative. A 24-week Phase 2b obesity trial of 536 participants did not produce significant weight loss³ versus placebo, and development for obesity was terminated in 2007; an earlier, smaller signal did not replicate. The supporting mechanism data remain animal and cell-based. So the best human evidence does not support the marketed fat-loss use; it argues against it.

Frequently asked questions

Does AOD-9604 actually help with fat loss?

The most rigorous human evidence , the Phase 2b obesity trial conducted by Metabolic Pharmaceuticals , did not demonstrate weight-loss efficacy versus placebo at 24 weeks. Preclinical rodent data consistently showed fat-mass reduction and increased fat oxidation, but those findings did not replicate in the larger human trial. Misra documented³ in a 2013 review in Current Cardiology Reviews that development was terminated in 2007 after a 24-week, 536-subject Phase 2b trial failed to induce significant weight loss. The claim that AOD-9604 is an effective fat-loss compound in humans is not supported by the available clinical evidence.

Is AOD-9604 the same as HGH?

No. AOD-9604 is a synthetic peptide corresponding to amino acids 177 to 191⁴ of the growth hormone C-terminus, with an added N-terminal tyrosine for stability , 16 amino acids total, not the 191 amino acids of full-length hGH⁵. The two compounds have distinct molecular structures, different receptor interactions, and different evidence bases. Orlovius and colleagues published evidence in 2013 that AOD-9604 does not register on the WADA⁶ hGH isoform immunoassay.

Is AOD-9604 FDA-approved?

No. AOD-9604 has never received FDA approval for any indication. Its history includes an attempt to position it as a food/supplement ingredient. Its nomination for the 503A bulks list was withdrawn, FDA lists it among substances that may present significant safety risks⁷, and as of September 2026 it is not eligible for 503A compounding.

Is AOD-9604 legal to buy in 2026?

As of September 2026, AOD-9604 is not eligible for compounding under Section 503A. Products sold as AOD-9604 through online vendors operate outside FDA oversight and lack pharmaceutical-grade manufacturing standards. The compound is not legally available by prescription through U.S. compounding pharmacies under the current regulatory framework.

Is AOD-9604 banned in sports?

Yes. AOD-9604 appears on the WADA Prohibited List⁸ and is prohibited at all times. Cox and colleagues confirmed its WADA-banned status and⁴ described a stable metabolite that may extend the detection window in a 2015 paper in Drug Testing and Analysis. Competitive athletes subject to anti-doping testing should not use products containing AOD-9604.

Can a doctor still prescribe AOD-9604?

As of September 2026, AOD-9604 is not eligible for compounding under Section 503A, meaning it is not available through the licensed compounding pharmacy pathway. There is no FDA-approved drug formulation of AOD-9604 that a licensed prescriber can prescribe.

What happened to the FDA Category 2 peptide list, and will these compounds become available again?

FDA's 503A Category 2 list covers bulk substances that raise significant safety risks, and as of September 2026 it holds only a handful of substances, not AOD-9604. FDA removed peptides from the list in April 2026⁷ after the nominations were withdrawn, which was not a finding that they are safe. A withdrawn substance is not eligible for 503A compounding unless FDA adds it to the 503A bulks list through rulemaking or places it in Category 1⁹, and no timeline for that exists for AOD-9604.

What is the difference between AOD-9604 and tesamorelin?

These are structurally unrelated compounds that target fat metabolism through different mechanisms. Tesamorelin is a stabilized GHRH analog that stimulates the pituitary to release endogenous growth hormone. AOD-9604 is a synthetic C-terminal fragment of hGH itself, proposed to act on adipose tissue directly without stimulating pituitary GH release. Tesamorelin has FDA approval¹⁰ to reduce excess abdominal fat in adults with HIV-associated lipodystrophy, supported by two randomized controlled trials including the Falutz and colleagues 2007 NEJM study¹¹. AOD-9604 has no FDA-approved indication and failed its Phase 2b obesity trial. This comparison is for scientific context only. These compounds have fundamentally different regulatory statuses and evidence bases.

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