AOD-9604: the growth hormone fragment that failed its obesity trials

AOD-9604 is the rare online peptide that went through real human trials, and the trials are the reason it never became a drug. It was developed in Australia as an obesity treatment, tested in six company-funded human studies (925 people, by the company’s count), and dropped in 2007 when its largest trial showed no meaningful weight loss. It now sells online as a “fat-burning” injection, which is the one route nobody has ever tested in a person. It is not FDA-approved, FDA’s advisory committee voted unanimously against compounding it, and vials labeled “for research use only” are not legal to use on people. For drugs that do have weight-loss approval, see the GLP-1 guide.

What AOD-9604 is

FDA describes AOD-9604 as “a hexadecapeptide that is a synthetic fragment of human growth hormone (hGH) (15 amino acids: 177-191) with an additional tyrosine at the N-terminal end.” In plain terms: the last 15 amino acids of the 191-amino-acid growth hormone molecule, with one more amino acid added at the front, making 16. It contains a disulfide bond, a sulfur bridge that loops the chain.

It was designed around growth hormone’s fat-burning (lipolytic) action. FDA’s review notes that in obese mice, AOD-9604 and growth hormone both cut weight gain by about 5% to 10% compared with untreated mice. FDA also found inconsistencies in what sellers supply: CAS numbers that do not match, and amino acid sequences on supplier websites that do not match the chemical structure they list.

What the human trials found

The developer, Metabolic Pharmaceuticals, ran six randomized, double-blind, placebo-controlled studies. FDA’s December 2024 briefing summarizes them:

On the amino acid count. Sources disagree, so here is the primary text. FDA’s briefing says AOD-9604 “is a hexadecapeptide, i.e., it contains 16 amino acids. It is a synthetic 177-191 fragment (15 amino acids) of hGH with an additional tyrosine at the N-terminal end.” Sixteen is the right number. Products sold as “hGH fragment 176-191” are named for the native fragment, which also has 16 residues but begins with phenylalanine instead of the added tyrosine, so the two names are not interchangeable even though sellers use them that way.

On February 21, 2007, the company announced that the phase 2b results “do not support the commercial viability” of AOD-9604 for obesity. FDA’s conclusion in 2024 was that “there is a lack of evidence to support the effectiveness” of either form of AOD-9604 for obesity “for any ROA [route of administration].” No study has tested it by subcutaneous injection, the way it is sold online. ClinicalTrials.gov lists no AOD-9604 studies.

What is the AOD-9604 dosage?

There is no established human dose, and there is no honest answer to the question as it is usually asked, which is how much to inject. Every published human study gave it by vein or by mouth. FDA states that it “did not find information on the proposed subcutaneous and transdermal use of AOD-9604 (free base) or AOD-9604 acetate in humans,” and that it found no pharmacokinetic or bioavailability data for any route, meaning nobody has measured how much of a dose reaches the blood or how long it stays there.

What the studies used, as history and not as guidance:

Two things stand out. The amounts differ by more than a hundredfold between studies, which is what a program looks like when it cannot find an amount that works. And the last and largest trial used the smallest amounts, after earlier data hinted that lower doses did more, a pattern FDA summarized as a dose response with “unclear meaningful therapeutic effects.”

The nominations that reached FDA proposed a 1,200 mcg/mL solution for injection under the skin, a 600 mcg oral capsule and a 600 mcg per gram cream. FDA evaluated those proposals and found no human data for the injectable or the cream. If you are holding a vial and trying to work out units, the arithmetic is simple enough, and the reconstitution calculator and mg/mL to units converter will do it. What arithmetic cannot supply is a tested amount, a schedule, or any confidence that the vial holds what the label claims.

What is known about safety

The company’s summary of its six trials (Stier et al. 2013), whose authors were company employees or consultants, reported no serious adverse events in the IV studies. Headache was the most common complaint. In the oral studies, the highest dose (54 mg) brought more headache, diarrhea and flatulence; one participant had diarrhea judged possibly related and one had pneumonia judged unrelated. FDA found no human pharmacokinetic data and no human data for injection under the skin or for creams.

Reading the company’s own safety summary, this is what was reported:

Those cancer cases deserve care in both directions. Five cases among 300 middle-aged adults over 12 weeks, mostly skin lesions, is not evidence that the drug causes cancer, and the investigators said as much. But the published detail is thin, FDA said there was not enough information to assess whether they were related, and nobody has followed anyone on this peptide for longer than six months.

Two findings cut against the usual marketing. In every study, the authors reported no statistically significant difference in IGF-1 (insulin-like growth factor 1) between drug and placebo, so AOD-9604 does not appear to act through the growth hormone pathway the way sellers imply. And in the subset tested, nobody developed antibodies against the peptide after swallowing it, which tells you nothing about injecting it.

FDA’s page of compounding substances with safety concerns says injected AOD-9604 “may pose significant risk for immunogenicity,” may have “complexities with regard to peptide-related impurities,” and that “FDA has also identified serious adverse events that may be associated with AOD-9604, though causality is not clear.” Its adverse event database held no reports for AOD-9604 through January 2024, and FDA’s reviewers warned that an absence of reports does not imply a substance is safe.

The GRAS claim

GRAS means “generally recognized as safe,” a status for food ingredients. A company can reach a GRAS conclusion itself, through experts it hires, without FDA ever reviewing it; it can then voluntarily notify FDA, which publishes the notices it receives in its GRAS notice inventory.

On June 25, 2012, the developer’s parent company announced “a conditional GRAS status determination by an expert scientific panel” for AOD-9604 as a food ingredient at up to 1 mg per person a day, conditional on publishing its safety studies. Its chief executive called it “a self-affirmed conditional GRAS status.” A 2014 trade report said the company had then announced full GRAS designation for foods, drinks and dietary supplements at the same limit. A nominator later cited “USA GRAS status” when asking FDA to allow AOD-9604 in compounding.

What this means:

• It is a food-ingredient determination made by experts the company hired, which the company itself called self-affirmed. It is not an FDA approval.
• It covers eating up to 1 mg a day. It says nothing about injecting the peptide, and an injectable product is a drug, not a food.
• FDA’s 2024 review treated AOD-9604 as a drug ingredient, searched its GRAS notice inventory among other databases, and still concluded the evidence weighed against it.

FDA status in detail

In Australia, FDA’s briefing notes, AOD-9604 has been added to the Poisons Standard as a performance and image enhancing drug, making possession without authority illegal.

If you have seen headlines about peptides becoming available in late 2026, they do not reach this one. As of November 2, 2026, HHS says it does not intend to take enforcement action over 503A compounding of six named peptides, on conditions. AOD-9604 is not among them, and nothing about its evidence has changed since FDA’s advisers rejected it.

WADA status

AOD-9604 is prohibited by name. The WADA Prohibited List places “growth hormone fragments, e.g. AOD-9604 and hGH 176-191” in section S2.2.3, among peptide hormones banned at all times, both in the 2026 list and in the 2027 list that takes effect January 1, 2027. FDA’s briefing also cites an Australian Crime Commission report in which footballers admitted using it.

What research use only means

Under 21 CFR 312.160, a “research use only” label allows shipment only for laboratory animal or test-tube work. It does not make injecting AOD-9604 legal. FDA found clinics marketing it as injections, capsules and dissolving tablets, alone and in blends with BPC-157 and other ingredients. None of these products has verified identity, purity, sterility or dose, and the sequence problems FDA found in supplier listings make the label on a vial especially hard to trust. The COA guide explains what a certificate can and cannot show.

What to watch for

• It did not work in trials. The largest controlled study found no significant weight loss, and the company ended development on that basis. Approved obesity drugs with large trials behind them exist, including tirzepatide.
• The route it is sold for is untested. Every human study used a vein or the mouth. There is no human data for injection under the skin, and none for the cream.
• Immune reactions. FDA flagged immunogenicity risk for the injectable, and a 16-amino-acid chain is long enough to be a plausible target.
• What is actually in the vial. FDA found CAS numbers that did not match and supplier sequences that did not match the structures listed beside them. The certificate of analysis guide covers what a test report can and cannot confirm.
• Blends. FDA found AOD-9604 sold mixed with BPC-157 and other ingredients, which makes any reaction impossible to attribute to one thing.
• Athletes. It is a named prohibited substance, so a positive test needs no judgment call.

PeptideSorted does not link to sellers of AOD-9604 or any other unapproved peptide.

Questions to ask before trying it

There is no approved AOD-9604 product, so there is no prescriber conversation in the usual sense. If a clinic has offered it, these questions are the quick test:

• What human evidence supports injecting this, given that FDA found none?
• On what legal basis is it supplied, since AOD-9604 is on no 503A bulks list?
• Where is the certificate of analysis, and which laboratory issued it?
• Is this a single ingredient or a blend?
• If fat loss is the goal, what would an approved treatment, or a structured diet and activity plan, do for me instead?

For the wider picture on this category, see are peptides safe and peptides for muscle growth. The FDA status tracker carries one dated row per peptide, AOD-9604 included.