What is AOD-9604? What it does, benefits and what the evidence shows

AOD-9604 is a synthetic peptide built from a short piece of human growth hormone, designed to keep growth hormone's fat-burning effect without its effects on blood sugar. It was developed by the Australian company Metabolic Pharmaceuticals as an obesity drug, and it worked in obese rats and mice. In people, it did not: the company's largest trial, in 536 adults with obesity, found no significant difference in weight loss versus placebo, and the company ended development for obesity in 2007. It has never been approved as a drug anywhere we could confirm, so anything you read about its fat-loss benefits in humans is running ahead of the data.

What AOD-9604 is and how it works

FDA's own review describes AOD-9604 as a synthetic cyclic peptide made of amino acids 177 to 191 of human growth hormone, with an extra tyrosine added at one end (FDA briefing document, Pharmacy Compounding Advisory Committee, December 4, 2024). The name stands for "anti-obesity drug 9604." It is not growth hormone, and it is a different thing from the growth hormone secretagogues like ipamorelin or the releasing hormone analogs like tesamorelin, which work by making your pituitary release more of your own growth hormone.

The idea came from work on which part of the growth hormone molecule drives fat breakdown. In obese mice, AOD-9604 and growth hormone both reduced body weight and body fat (Heffernan et al., Endocrinology, 2001), and FDA's review of the animal work notes that, unlike growth hormone, AOD-9604 had no apparent effect on blood sugar or insulin in those studies (FDA briefing document). In obese rats given the peptide orally, weight gain over the treatment period was less than half that of controls, with no harm to insulin sensitivity (Ng et al., Hormone Research, 2000). How it works is still unclear. FDA's reviewers noted that AOD-9604 is unlikely to act through the growth hormone receptor, and that its molecular target and mechanism remain unknown (FDA briefing document).

What people use it for

What the research actually shows

Fat loss: the human trials

Nearly everything we know about AOD-9604 in humans is summarized in FDA's 2024 briefing document, which reviewed the published record and the company's own disclosures. The picture is consistent.

The earliest human studies were small and short: one in 23 adults with obesity given the peptide intravenously, one in 16 men with obesity given it orally, and one in 36 men. In the first two, blood fatty acids rose after dosing, which is the biological signal the drug was meant to produce, but weight loss was not statistically different from placebo in the studies where it was reported. The reviewers noted these studies were described only briefly in a published overview, with limited detail on methods and results.

A 2005 conference abstract described a placebo-controlled trial in 300 adults with obesity. Its authors reported greater weight loss than placebo at all doses and a statistically significant smaller waistline, but FDA's reviewers observed that the weight difference was small, the dose response was irregular, and the abstract gave too little data to judge whether the effect was meaningful.

The trial that settled it was the company's Phase 2b study, called OPTIONS: a randomized, double-blind, placebo-controlled trial with 536 adults enrolled (502 randomized) who had obesity, run alongside a supervised diet and exercise program, at three oral doses of AOD-9604. In February 2007 the company announced that the results "do not support the commercial viability of the drug as a treatment for obesity" and that development for that use was terminated. FDA's review adds that this trial was not published in the medical literature, that weight loss versus placebo "was too low to reach statistical significance" at both the primary and the final endpoint (quoting the company), and that the reviewers found no registered trials of AOD-9604 on ClinicalTrials.gov (FDA briefing document). FDA's conclusion: "In most of the studies we identified, AOD-9604 failed to show benefit for weight reduction when compared to placebo."

There is also a route problem for anyone buying vials. Every human study FDA identified used oral or intravenous administration. The agency found no human data on injecting AOD-9604 under the skin, and none on a skin cream, the forms most commonly sold to consumers (FDA briefing document).

Joints and cartilage

The joint-health claim rests on one rabbit study. In rabbits with chemically induced knee osteoarthritis, injections of AOD-9604 into the joint improved cartilage scores compared with saline, and AOD-9604 combined with hyaluronic acid did better than either alone (Kwon and Park, 2015). That is a small animal experiment with a direct injection into the joint. FDA's reviewers noted they did not find clinical studies of AOD-9604 in osteoarthritis or osteoporosis (FDA briefing document). We found no human trial for this use either.

Muscle, skin, anti-aging

We found no published human trial for any of these. FDA's review lists them among the many uses that clinics and wellness sites market AOD-9604 for, alongside weight loss and cholesterol, without supporting studies (FDA briefing document).

Regulatory status

AOD-9604 is not a component of any FDA-approved drug, and there is no USP monograph for it, according to FDA's 2024 review. That review was part of FDA's evaluation of whether AOD-9604 could be used in pharmacy compounding. FDA proposed that it not be placed on the 503A bulks list, citing a lack of evidence of effectiveness for obesity and safety concerns. On December 4, 2024, the Pharmacy Compounding Advisory Committee voted 0 to 12 against placing AOD-9604 on the list (FDA, final summary minutes). FDA's bulk-substances page (content current as of April 22, 2026) lists AOD-9604 under 'nominated but withdrawn,' saying compounded drugs containing it may pose significant immunogenicity risk and that FDA has identified serious adverse events that may be associated with AOD-9604, though causality is not clear (FDA, bulk drug substances that may present significant safety risks).

Side effects and risks

No one has run a long-term safety study. The human safety data FDA reviewed came from a company summary of six randomized trials, using oral or intravenous dosing over short periods. In the oral trials, headache, diarrhea and flatulence were the most commonly reported effects; in the intravenous studies, headache, fatigue, dizziness and low blood sugar were most common, and chest tightness and euphoria were reported as possibly related. One oral trial reported several cancers among participants, including breast cancer and melanoma. The investigators judged them unrelated to the drug, but FDA's reviewers wrote that they "have concerns" and that the information was insufficient to say the cancers were unrelated (FDA briefing document). That is a flag from a small, company-run data set, not evidence that the drug causes cancer.

Animal toxicology findings also give pause. FDA noted that in a long-term rat study, oral AOD-9604 changed a blood marker of bone turnover in a dose-dependent way, and that in a months-long monkey study there were minimal changes in liver cells that could indicate liver injury. Genotoxicity tests gave equivocal results (FDA briefing document). None of this proves harm in humans, and the reviewers said the animal work was too limited to interpret.

The immune system is the risk most relevant to buyers. FDA's reviewers wrote that a 16-amino-acid peptide has the potential to provoke an immune response, that this risk is generally higher with injection under the skin than with intravenous use, and that impurities or clumping of the peptide could make it worse. They found no information on the immune response to subcutaneous AOD-9604 (FDA briefing document). The same review reported that FDA's adverse-event database had no reports for AOD-9604 through January 2024 and said that does not mean the substance is safe; FDA's April 2026 bulk-substances page, however, says the agency has identified serious adverse events that may be associated with AOD-9604, though causality is not clear (FDA bulk-substances page).

What the lab tests show

The sample here is tiny, so read it as an anecdote rather than a verdict on any vendor. Today, our database has 8 vials of AOD-9604 from 4 vendors, drawn from 6 lab reports dated January 2025 to August 2025.

As of September 29, 2026, two of the 8 vials were empty: the lab detected no peptide at all. Those are the only 2 that meet our failure definition (empty, under 95% pure, more than 20% under label, or more than 50% over). The other 6 vials all measured 99% pure or better, with a median of about 99.3%. Their measured amount versus the label ranged from about 15% under to 5% over, with a median of about 1% under; 3 landed within 5% of label, 5 within 10%, and none was more than 20% off.

Put plainly, when the vial contained peptide, it was pure and close to label. The problem was that 1 vial in 4 had nothing in it. With only 8 vials across 4 vendors, we would not draw any conclusion about which vendors are better or worse. What the data does support is that an empty vial is a real possibility for this compound, and that a posted certificate is worth double-checking.

Here is how the ranked vendors for AOD-9604 look right now. The table shows current verdicts and flags any vendor with more than 5% failed vials. Ranking requires five or more lab reports per vendor, so with data this thin it may be short or empty:

Buying smarter

Check the vendor's record for this compound on the AOD-9604 results page, and look at how many reports sit behind any score and how recent they are. Our vendors page and methodology explain how scores work. Treat a vendor-posted certificate as a starting point rather than proof; how to read a peptide COA and fake peptide COAs cover what to look for. If your goal is real fat loss, it is worth knowing the compounds with actual approvals and weight-loss trials behind them, such as semaglutide, tirzepatide or liraglutide.

Because empty vials showed up in our small sample, testing your own vial is worth the money. How to get a peptide tested walks through ordering independent identity, purity and quantity testing. If your report comes back with a fail, stop using that batch, tell anyone who bought from the same run, take the report to the vendor, and submit it to VendorVerify.

Database figures without a date update automatically from VendorVerify's lab results; dated figures are snapshots. This isn't medical advice. AOD-9604 is not an approved drug, and vials sold under its name are sold for research use only.