What is AOD-9604?

What sources report

FDA describes the AOD-9604 peptide as a synthetic chain of 16 amino acids: residues 177 to 191 of human growth hormone (hGH), with an extra tyrosine at the N-terminal end.¹ Its two cysteines are linked by a disulfide bond,²³ and PubChem's DrugBank-sourced entry calls it a synthetic analogue of the lipolytic, or fat-breaking, domain of hGH.⁷ The added tyrosine is described as stabilizing the peptide, which is made by solid-phase peptide synthesis.⁴ Metabolic Pharmaceuticals, an Australian company, developed and patented it in the late 1990s as an obesity drug candidate.¹²

How it is thought to work

Its developers hypothesized that it cannot switch on the growth hormone receptor, because it lacks the second receptor-binding site that hGH uses.⁴ In cell tests, AOD-9604 did not compete with hGH for that receptor and did not make cells multiply.¹⁰ In obese mice given 14 days of injections into the abdominal cavity, both hGH and AOD-9604 restored the low RNA levels of the beta-3 adrenergic receptor, the main fat-releasing receptor of fat cells, to those of lean mice.¹¹ In mice bred without that receptor, long-term treatment no longer changed body weight, yet a short experiment still raised fat burning, and the authors concluded that the fat-breaking action is not mediated directly through the receptor.¹¹ FDA's 2024 review concluded that the molecular target and mechanism of action remain unknown.¹

Animal studies

Most of the encouraging data come from rodents.¹²¹⁰ Obese Zucker rats given AOD-9604 by mouth for 19 days gained less than half as much weight as untreated rats.¹² Obese mice treated for 14 days gained less weight and burned more fat, and unlike hGH, AOD-9604 did not raise their blood sugar.¹⁰ A 2015 study in rabbits with induced knee arthritis found that injections into the joint improved cartilage regeneration.¹³ Full list with evidence levels: AOD-9604 benefits and uses.

Human trials

Between 2001 and 2006, the developer funded six randomized, double-blind, placebo-controlled trials in 893 adults, all but one in people with obesity, giving AOD-9604 by vein or by mouth.⁴ In a 12-week trial in 300 adults taking capsules, every dose group lost more weight on average than placebo, but the best dose fell short of significance overall (p=0.1) and reached it only in the female subgroup.⁴² The larger 24-week OPTIONS trial randomized 502 adults, all on a dietitian-supervised diet and exercise program,⁴² and found weight loss beyond placebo of under 1 kg in every dose group, too small to reach statistical significance.² The company ended obesity development on February 21, 2007.²

FDA found no report of the 24-week trial in the medical literature, and a 2026 review notes that the conclusion of no benefit rests mainly on sponsor-reported results.¹⁸ FDA's 2024 review found a lack of evidence that it is effective for obesity by any route.¹ Researchers who need the compound for laboratory work can find AOD-9604 for sale as a research vial.

How it differs from growth hormone

The trial authors note that long-term hGH treatment is linked to glucose intolerance, insulin resistance, diabetes, acromegaly, cancer, edema and high blood pressure.⁴ In the AOD-9604 trials, by contrast, they found no effect on blood IGF-1 and no worsening of glucose tolerance, and they conclude that it does not act through IGF-1.⁴ The cell tests above also found that it does not bind the hGH receptor.¹⁰ More on the full hormone: What is HGH?.

Side effects

In the developer's trials, headache was the most common complaint, the oral studies also recorded gut symptoms such as diarrhea, and the authors judged the overall profile indistinguishable from placebo.⁴ A few events were judged possibly related to AOD-9604, including euphoria in 5 of 23 men during IV dosing and one case of chest tightness.⁴ Five tumors in the 12-week trial, four of them cancers and all in AOD-9604 groups, were judged not related to treatment by the investigator, but FDA says the information is insufficient to decide.⁴¹ Full list: AOD-9604 side effects.

Dosage information

AOD-9604 has no established human dose and no approved use.⁸ Oral doses in the trials ranged from 0.25 to 54 mg and single IV doses from 25 to 400 micrograms per kg of body weight, and FDA found no human study of injection under the skin.⁴¹ These are research doses, not guidance for people. Published doses by species, route and duration: AOD-9604 dosage.

Reconstitution and storage

No USP monograph or approved product label sets a preparation standard for AOD-9604.¹ In the two early IV trials, the drug was supplied as a freeze-dried powder and mixed with sterile water for injection before use.⁴ Supplier documents cited by FDA list the free base as soluble in water up to 2 mg per mL and give long-term storage temperatures of -18 to -20 °C.¹ Lab steps, concentration math and storage after mixing: How to reconstitute AOD-9604.

Regulatory status

United States. AOD-9604 is not FDA-approved and is not an ingredient of any FDA-approved drug,¹ and a 2026 review states that no major regulator has approved it for any indication.⁸ It sat in FDA's category 2, bulk substances for compounding that may present significant safety risks, until its nominations were withdrawn.¹⁶ FDA's safety-risks page, current as of April 22, 2026, still names it and warns of possible immune reactions, impurity and characterization problems, and serious adverse events whose cause is not clear.¹⁶ FDA then reviewed it on its own initiative and proposed not adding it to the 503A Bulks List, its list of bulk drug substances that can be used to compound drugs under section 503A.¹ On December 4, 2024, FDA's Pharmacy Compounding Advisory Committee voted 12 to 0 against adding it.⁶ It is absent from FDA's 503A nominations list updated May 14, 2026, and was not on the agenda of the July 23 to 24, 2026 advisory meeting on peptides.¹⁷¹⁸ As of October 25, 2026, the list in federal regulations (21 CFR 216.23) names six substances, and no peptide is among them.²⁴

Sport. The 2026 WADA Prohibited List, in force since January 1, 2026, names AOD-9604 under S2.2.3 (growth hormone, its analogues and fragments), banned at all times, in and out of competition.³ An Australian Crime Commission report listed it among peptides supplied to athletes.¹ US anti-doping scientists report that it has been found in confiscated vials in the USA, and they validated a urine test that detects it down to 50 pg/mL.¹⁵

Australia. FDA's 2024 review reports that Australia's Advisory Committee on Medicines Scheduling recommended and confirmed adding AOD-9604 to the Poisons Standard as a performance and image enhancing drug, which is illegal to possess without authority.¹

Food ingredient claim. Papers by authors tied to the developer say a GRAS expert panel judged AOD9604 generally recognized as safe for foods, drinks and supplements, on condition that its safety data were published.¹⁴⁴¹ FDA's GRAS Notice Inventory held no notice for AOD9604 when searched on October 24, 2026, so no FDA response to that claim is on record.¹⁹

Trial registries. ClinicalTrials.gov returned no AOD9604 studies when queried on October 24, 2026.²⁰ The 24-week trial was registered in Australia in August 2005 as ACTRN12605000067673, is marked completed, and has no result documents posted.²¹