What is AOD-9604? Research, FDA review and Philippines status

Not yet medically reviewed. Fact-checked against the sources listed below on October 7, 2026.How we write and review

Last updated October 7, 2026

AOD-9604 is a lab-made fragment of human growth hormone, tested in Australia as an obesity pill. In its largest trial, with 536 people enrolled, weight loss was not significantly different from placebo, and development for obesity stopped in 2007. The US FDA says no approved drug contains it. WADA bans it, and no FDA Philippines record was found.

Key takeaways

AOD-9604 is a synthetic 16 amino acid peptide: the tail end of human growth hormone (amino acids 177 to 191) with an extra tyrosine added. It is also labelled hGH 176-191.
Its developer, Metabolic Pharmaceuticals, ran a 24-week phase 2b trial (536 enrolled). The US FDA summarises the result as no significant difference in weight loss between AOD-9604 and placebo. In February 2007 the company ended development for obesity.
In December 2024 a US FDA advisory committee voted 0 to 12 against adding AOD-9604 to the list of substances US pharmacies may use for compounding. The FDA found a lack of evidence that it works for obesity and too little safety data.
Claims about joints rest on one study in 32 rabbits. The US FDA found no human osteoarthritis or osteoporosis studies.
WADA names AOD-9604 in class S2 (growth hormone fragments) on its 2022, 2026 and 2027 lists; the 2026 list prohibits class S2 at all times. Australia lists it as a prescription-only (Schedule 4) substance.
No record of AOD-9604 was found in an FDA Philippines Verification Portal search on October 7, 2026, and no FDA Philippines advisory naming it was found.

What is AOD-9604?

AOD-9604 is a synthetic peptide made of 16 amino acids, with the sequence YLRIVQCRSVEGSCGF. It copies the last part of human growth hormone, amino acids 177 to 191, with an extra tyrosine added at the start to stabilise it. Researchers described this part of growth hormone as its "lipid mobilizing domain".

It goes by several names: AOD9604, Tyr-hGH 177-191, hGH 176-191 and "anti-obesity drug 9604". A 2026 review explains that the extra tyrosine is why it is "sometimes labelled 'hGH 176-191' or just 'GH fragment'".

Metabolic Pharmaceuticals developed it and tested it in Australia. The US FDA describes it as a peptide with a disulfide bond between the two cysteines at positions 7 and 14, made by solid-phase synthesis. The FDA treats AOD-9604 (free base) and AOD-9604 acetate as two separate substances.

It is investigational. The US FDA says no FDA-approved drug product contains AOD-9604, and it found no listing for it on the European Medicines Agency website or in the European, Chinese, Indian or Japanese pharmacopoeias.

How was AOD-9604 thought to work?

The idea was to keep growth hormone's fat-burning signal without its effects on growth and IGF-1. A 2026 review says it was designed to keep growth hormone's fat-breakdown signalling while avoiding growth effects and IGF-1 driven exposure.

What the early animal and lab work proposed:

Fat breakdown without the growth hormone receptor: in obese mice, AOD9604 increased fat breakdown (lipolysis) and fat oxidation without binding the growth hormone receptor.
Not through the beta-3 receptor: it raised levels of the beta-3 adrenergic receptor in mouse fat, but the authors concluded its fat-breakdown actions "are not mediated directly through the beta(3)-AR".
No IGF-1 effect in people: in human trials summarised by the developer's authors, AOD9604 had no effect on serum IGF-1 levels.

These are proposed mechanisms from animal studies and company-funded trials. They do not show that AOD-9604 causes weight loss in people.

What did the animal studies show?

The early results that led to human trials came from rodents.

Study	Animals	What was reported
Ng et al. 2000, Monash University	Obese Zucker rats, 19 days of AOD9604 by mouth	Body weight gain fell by over 50% compared with control, fat tissue showed more fat breakdown, and there was no adverse effect on insulin sensitivity
Heffernan et al. 2001	Obese mice, 14 days	Both growth hormone and AOD9604 reduced body weight gain and increased fat oxidation. Unlike growth hormone, AOD9604 did not cause high blood sugar, did not reduce insulin release and did not cause cell growth in a lab test

These were short studies in animals. As the next section shows, the human trials did not confirm a meaningful effect on weight.

What did the human trials show?

AOD-9604 reached phase 2b trials as an oral obesity drug in Australia, sponsored by its developer. The phase 2b efficacy results were never published in a peer-reviewed journal.

Trial	People	Design	What was reported	Limits
OPTIONS study (METAOD006), phase 2b	536 enrolled, 502 randomized, adults with obesity	Double-blind, placebo-controlled, three doses by mouth or placebo, plus a supervised diet and exercise program, 24 weeks	The US FDA's summary of the company's disclosure: "there was not a significant difference in the primary endpoint of weight loss between placebo and AOD-9604." The company said weight loss versus placebo at 12 or 24 weeks "was too low to reach statistical significance"	Not published in the medical literature. Funded by the developer
METAOD005, phase 2b	300 adults with obesity	Double-blind, placebo-controlled, five doses by mouth or placebo, 12 weeks	A 2005 meeting abstract reported more weight loss on all doses than placebo, and called the largest effect "significant" for females	The US FDA says the differences were small, with "unclear meaningful therapeutic effects", and it found no publication of the methods and results
Six trials summarised by Stier, Vos and Kenley (2013)	About 900 adults	One phase 1, three phase 2a and two phase 2b trials, all randomized, double-blind and placebo-controlled	No effect on serum IGF-1, no negative effect on glucose tolerance, no anti-AOD9604 antibodies in tested patients, and no withdrawal or serious adverse event judged related to AOD9604	Efficacy results are not reported. All six trials were funded by the developer, and the authors worked for or consulted for it

The OPTIONS trial was registered on the Australian New Zealand Clinical Trials Registry on August 2, 2005 (ACTRN12605000067673). Its status is completed, and no results are posted on the record.

No AOD-9604 trials are listed on ClinicalTrials.gov. A search on October 7, 2026 returned no studies, and the US FDA's 2024 review found the same.

Why was development stopped?

The developer stopped because its own phase 2b results did not support the drug. In February 2007, Metabolic Pharmaceuticals announced that the results "do not support the commercial viability of the drug as a treatment for obesity" and ended development for obesity.

The US FDA reached a similar view in 2024. It concluded there is "a lack of evidence to support the effectiveness" of AOD-9604 for obesity, by any route.

Does AOD-9604 help joints or osteoarthritis?

There is no human evidence. The only osteoarthritis study found was in rabbits.

Study	Animals	What was reported
Kwon and Park 2015	32 rabbits with chemically induced knee osteoarthritis, given weekly injections into the knee of AOD9604, hyaluronic acid, both, or saline	Cartilage scores improved compared with saline in all treated groups. AOD9604 combined with hyaluronic acid scored above either alone and shortened lameness

AOD-9604 was nominated to the US FDA for osteoarthritis and osteoporosis as well as weight loss. The FDA did not evaluate those two uses because the nominations lacked enough information, "and FDA did not identify clinical studies using AOD-9604 related BDSs in these populations in its own literature search."

The FDA also found wellness clinics and medical spas marketing AOD-9604 for osteoarthritis, osteoporosis, weight loss and anti-aging.

Risks and unknowns

The safety of AOD-9604 in people is not established. The US FDA says it "has identified no, or only limited, safety-related information", so it "lacks sufficient information to know whether the drug would cause harm when administered to humans."

What the US FDA has found (2024 review and its safety risks page):

Animal toxicity signals: in rats given AOD-9604 by mouth for 13 weeks, signals suggesting negative effects on bone health. In monkeys given it by mouth for 9 months, signals that could indicate liver toxicity. In lab and animal genotoxicity tests, equivocal mutagenic signals. The FDA called these studies "too limited in scope to inform safety considerations" for oral, injected and skin use.
Immune reactions: compounded AOD-9604 "may pose significant risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and API characterization."
Routes never studied: no human studies of AOD-9604 injected under the skin or applied through the skin, and no human pharmacokinetic data for any route. The human trials gave it by mouth or into a vein.
Serious adverse events: the FDA says it "has also identified serious adverse events that may be associated with AOD-9604, though causality is not clear."
No reports in FAERS: a search of the FDA's adverse event reporting system through January 7, 2024 found no reports for AOD-9604. The FDA cautioned that having no reports does not show the substance is free of toxicities.

Growths reported in the 12-week trial. According to the 2013 safety summary by Stier, Vos and Kenley, five participants taking AOD9604 in METAOD005 had cancers or growths reported: basal cell carcinoma, lipoma, squamous cell carcinoma, malignant melanoma and breast cancer. The study's principal investigator judged none of them related to the study drug. The summary's authors were employed by or consulted for the developer.

Side effects in early studies. Reported side effects included headache (the most common in one intravenous study), fatigue, dizziness, diarrhoea, flatulence, nausea and increased appetite. In one intravenous study, one report of chest tightness and five reports of mild or moderate euphoria were judged possibly related to AOD-9604. The FDA notes that the published reports give few details. The highest oral dose tested in short studies was associated with more stomach and gut side effects.

Product quality. The FDA considers both forms of AOD-9604 "not physically and chemically well characterized". The certificate of analysis sent with the nomination did not include tests for impurities, aggregates, microbial limits or bacterial endotoxins. The FDA adds that the peptide's disulfide bond "can lead to degradation" and clumping.

What reviewers say. A 2026 review in Frontiers in Endocrinology groups AOD9604 with unregulated growth hormone axis peptides sold as "research compounds", and notes "uncertainty surrounding product composition, dose, and stacking practices in unregulated supply chains". A 2026 Sports Medicine review includes AOD-9604 among unapproved peptides marketed direct to patients and says "rigorous human safety data are scarce, and there is potential for serious harm to patients."

Seized products. A 2015 anti-doping study reports that AOD9604 "is available on several Internet websites and was recently identified in confiscated vials in the USA". A 2014 case report from Belgium's Scientific Institute of Public Health concerns AOD9604 found in unknown pharmaceutical preparations seized by Belgian authorities.

What is the US FDA's position on AOD-9604?

The US FDA has not approved AOD-9604, and in 2024 it proposed keeping it off the list of substances US pharmacies may use for compounding.

Date	What happened
Earlier (date not confirmed)	AOD-9604 was in category 2 of the FDA's interim compounding policies, for substances that may present significant safety risks. The nomination was later withdrawn
2024	The FDA evaluated AOD-9604 (free base) and AOD-9604 acetate for obesity and proposed that neither be added to the 503A bulks list. It said use in compounding "may raise safety concerns"
December 4, 2024	The FDA's Pharmacy Compounding Advisory Committee voted 0 yes, 12 no and 0 abstain on adding AOD-9604 to the 503A bulks list
April 22, 2026	The FDA's safety risks page lists AOD-9604 under "Bulk drug substances nominated but withdrawn", described as substances "previously in category 2"
May 14, 2026	The FDA's 503A nominations list does not include AOD-9604 in categories 1, 2 or 3
As of October 7, 2026	No final FDA decision after the December 2024 vote was found

The FDA's reason, in its own words: "a balancing of the criteria weighs against both AOD-9604 (free base) and AOD-9604 acetate being placed on that list". It also notes that US outsourcing facilities reported compounding no AOD-9604 products from 2017 to 2023.

Food ingredient claims. The developer's 2013 paper says a panel of experts found AOD9604 to be GRAS, a US food ingredient status, for its intended food uses. That was a panel convened for the company, not an FDA decision. The FDA's GRAS Notice Inventory (download last updated October 6, 2026) has no entry for AOD-9604 or its developer, so no FDA response to a GRAS notice was found.

Is AOD-9604 legal in Australia?

Australia, where AOD-9604's 24-week phase 2b trial ran, lists it as a prescription-only substance. The Poisons Standard (June 2026, in force from June 1, 2026) lists "AOD-9604 (CAS No. 221231-10-3)" in Schedule 4, prescription only medicines.

It also lists AOD-9604 in Appendix D, clause 5: "Poisons for which possession without authority is illegal (for example, possession other than in accordance with a legal prescription)". Whether any AOD-9604 product is on the Australian Register of Therapeutic Goods was not checked.

Is AOD-9604 banned in sport?

Yes. The World Anti-Doping Agency (WADA) names AOD-9604 as a growth hormone fragment, prohibited at all times.

Year	WADA position
2013	WADA statement: AOD-9604 "is a substance still under pre-clinical and clinical development and has not been approved for therapeutic use by any government health authority in the world". WADA placed it in class S0, non-approved substances
2022 list	Named in class S2 as an example of "growth hormone fragments, e.g. AOD-9604 and hGH 176-191"
2026 list	Named in class S2.2.3, "Growth hormone (GH), its analogues and fragments". Class S2 is prohibited at all times, in and out of competition
2027 list (in force from January 1, 2027)	Same S2.2.3 entry: "growth hormone fragments, e.g. AOD-9604 and hGH 176-191"

WADA issued its 2013 statement after inquiries about AOD-9604 "available on the Internet 'black market' and possibly elsewhere". All substances in class S2 are non-Specified Substances under the 2026 list.

USADA's 2027 advisory lists AOD-9604 and hGH 176-191 among peptides "not approved for human use by regulatory authorities" that are prohibited in sport. Anti-doping laboratories have also validated a urine test for AOD9604 (Cox et al., 2015).

Legal status in the Philippines

The FDA Philippines status of AOD-9604 is unverified. No record was found in an FDA Philippines Verification Portal search on October 7, 2026.

What was checked on October 7, 2026:

Verification Portal: searches for "AOD9604" and "AOD-9604" returned no record in any category. A broader search for "AOD" returned only unrelated establishment records.
FDA Philippines website: searches for "AOD-9604", "AOD9604", "AOD 9604", "growth hormone fragment" and "hormone fragment" each returned no results.
Prescription status: no Philippine source was found on whether AOD-9604 needs a prescription, or on any legal way to obtain it.

A search with no record is not an official FDA Philippines statement about a compound. To check a product yourself, search the portal at verification.fda.gov.ph. For how Philippine rules treat peptides in general, see are peptides legal in the Philippines.

FDA advisory history

No FDA Philippines advisory naming AOD-9604 was found. A search of the FDA Philippines website for "AOD" on October 7, 2026 matched only unrelated advisories through parts of other product names, and the three advisories opened did not mention AOD-9604.

A missing advisory does not mean a product is registered or approved. For comparison, FDA Philippines has issued advisories on specific unregistered tirzepatide vial products.

What to ask a doctor

If you are considering AOD-9604, or have already used it, a licensed doctor can help. Questions you could bring:

What approved treatments exist for my weight or joint problem, and what does the evidence show for them?
What should I watch for if I have already used an unapproved peptide?
If I compete in sport, how does the WADA Prohibited List affect me?
How can I check whether a product is registered with FDA Philippines?

Frequently asked questions

What is AOD-9604?

AOD-9604 is a synthetic peptide of 16 amino acids. It copies the end of human growth hormone (amino acids 177 to 191) with an extra tyrosine at the start. Its developer, Metabolic Pharmaceuticals, tested it in Australia as an oral obesity drug.

Does AOD-9604 work for weight loss?

The trials do not show that it does. In the largest trial, a 24-week phase 2b study with 536 people enrolled, the US FDA reports no significant difference in weight loss between AOD-9604 and placebo. In 2024 the US FDA concluded there is "a lack of evidence to support the effectiveness" of AOD-9604 for obesity.

Why was AOD-9604 development stopped?

In February 2007 the developer announced that its phase 2b results "do not support the commercial viability of the drug as a treatment for obesity" and ended development for obesity. The full results were never published in a peer-reviewed journal.

Is AOD-9604 approved by the US FDA?

No. The US FDA says there are no FDA-approved drug products containing AOD-9604. In December 2024 its Pharmacy Compounding Advisory Committee voted 0 yes and 12 no on adding it to the list of substances US pharmacies may use in compounding.

Is AOD-9604 legal in the Philippines?

Its status is unverified. No record was found in an FDA Philippines Verification Portal search on October 7, 2026, and no Philippine source on a prescription route or any legal way to obtain it was found. A search result with no record is not an official FDA Philippines statement.

Is AOD-9604 the same as hGH 176-191?

The names are used for the same fragment. A 2026 review says AOD-9604 is often described as hGH 177-191 with an extra tyrosine, "hence sometimes labelled 'hGH 176-191' or just 'GH fragment'". WADA names both AOD-9604 and hGH 176-191 as examples of growth hormone fragments.

Does AOD-9604 help joints or osteoarthritis?

This has not been tested in people. The only osteoarthritis study found was in 32 rabbits with chemically induced knee damage. The US FDA did not identify any clinical studies of AOD-9604 in osteoarthritis or osteoporosis.

Is AOD-9604 banned in sport?

Yes. The WADA 2026 Prohibited List names AOD-9604 in class S2.2.3 as a growth hormone fragment, prohibited at all times, in and out of competition. The 2027 list, in force from January 1, 2027, keeps the same entry.

What are the side effects of AOD-9604?

Early human studies reported headache, fatigue, dizziness, diarrhoea, flatulence, nausea and increased appetite, and the highest oral dose tested was associated with more stomach and gut side effects. The US FDA says it has too little safety information to know whether AOD-9604 would cause harm in humans.

Has AOD-9604 been tested as an injection?

The US FDA found no human studies of AOD-9604 injected under the skin or applied through the skin. The human trials gave it by mouth or into a vein, and FDA found no human pharmacokinetic data for any route.

Does AOD-9604 raise IGF-1 or blood sugar?

A 2013 safety summary of six human trials reported no effect on serum IGF-1 and no negative effect on glucose tolerance. All six trials were funded by the developer, and the summary's authors worked for or consulted for it.

Is AOD-9604 a prescription medicine in Australia?

Australia's Poisons Standard (June 2026) lists AOD-9604 in Schedule 4, prescription only medicines. It is also listed in Appendix D among poisons for which possession without authority, such as without a legal prescription, is illegal.

Sources

This content is for education only and is not medical advice. Talk to a licensed doctor before starting any treatment.

What is AOD-9604? Research, FDA review and Philippines status

What is AOD-9604?

How was AOD-9604 thought to work?

What did the animal studies show?

What did the human trials show?

Why was development stopped?

Does AOD-9604 help joints or osteoarthritis?

Risks and unknowns

What is the US FDA's position on AOD-9604?

Is AOD-9604 legal in Australia?

Is AOD-9604 banned in sport?

Legal status in the Philippines

FDA advisory history

What to ask a doctor

Frequently asked questions

Sources

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