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Peptide Profile

AOD-9604

Advanced Obesity Drug 9604

A synthetic fragment of human growth hormone designed for fat metabolism. Excellent safety record, but failed its pivotal Phase IIb weight loss trial.

Reviewed March 2026·16 min read·12 citations·Research compoundFailed Phase IIb

Regulatory update: February 2026

AOD-9604 has been announced for reclassification from Category 2 to Category 1, which would allow compounding pharmacies to produce it legally. This change was announced February 27, 2026 but has not yet been formally published in the Federal Register.

Updated March 17, 2026

At a glance

AOD-9604 is a synthetic fragment of human growth hormone designed to isolate the fat-burning effects of GH without raising IGF-1 or disrupting blood sugar. It has an excellent safety record from 900+ trial participants. However, its pivotal Phase IIb trial for weight loss failed — and most marketing claims ignore that fact.

Animal studiesModerate10+ studies

Consistent fat reduction in obese mouse and rat models. Results did not translate to human efficacy in the Phase IIb trial.

Human evidenceLimited6 trials

Phase IIa showed modest weight loss (2.6 kg vs 0.8 kg). Phase IIb (OPTIONS, n=536) failed its primary endpoint. Safety proven across 900+ participants, but efficacy was not.

Safety dataModerate900+ subjects

Excellent safety record across 6 controlled trials with 900+ participants. No serious adverse events, no hormonal effects, safety profile indistinguishable from placebo.

How are these scores calculated?

AOD-9604 has genuinely excellent safety data — and a failed efficacy trial. Here's what that means: the compound is well-tolerated and does not cause the hormonal side effects of growth hormone. But its pivotal weight loss trial did not work. Most of what you'll read online omits this.

New research, delivered clearly

When new studies publish or clinical trials report results, we'll break them down in plain language.

Quick facts

Molecular weight
1,815.1 Da
Amino acids
16 (hexadecapeptide)
CAS Number
221231-10-3
First developed
~1997 (Monash University, Australia)
FDA status
Not approved — PCAC voted against 503A (Dec 2024)
WADA status
Prohibited (Section S0)

Amino acid sequence

Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe


What is AOD-9604?

AOD-9604 stands for Advanced Obesity Drug 9604. It's a synthetic peptide — a chain of 16 amino acids — corresponding to the C-terminal fragment (amino acids 177-191) of human growth hormone, with an added tyrosine at the N-terminus for stability.[1]

The compound was developed in the 1990s at Monash University in Australia by Professor Frank Ng's laboratory. The core idea was elegant: growth hormone has both growth-promoting effects (which raise IGF-1, affect blood sugar, and can cause tissue overgrowth) and fat-burning effects. Could you isolate just the fat-burning part? AOD-9604 was the attempt to do exactly that.[3]

In that narrow sense, the science worked. AOD-9604 does not raise IGF-1, does not disrupt glucose metabolism, and does not cause the hormonal side effects associated with full-length growth hormone. That metabolic selectivity is well-established across multiple human trials.

The problem came when researchers tested whether this metabolically selective compound actually caused meaningful weight loss in humans. It did not — at least not at the doses tested in the pivotal trial.


How it works

In plain terms, AOD-9604 is designed to activate the fat-burning part of growth hormone's activity without triggering the growth-promoting part. In animal studies, it stimulates the breakdown of stored fat (lipolysis) and inhibits the formation of new fat (lipogenesis).[2]

Think of growth hormone as having two major functions: one that tells cells to grow (which also raises IGF-1 and can affect blood sugar) and one that tells fat cells to release their stored energy. AOD-9604 was engineered to activate only the second function.

Detailed mechanism (for advanced readers)

AOD-9604's mechanism of action is not fully characterized, but the established pathways from preclinical research include:

  • Lipolysis activation: Stimulates hormone-sensitive lipase (HSL) in adipocytes, promoting breakdown of stored triglycerides into free fatty acids.
  • Lipogenesis inhibition: Reduces the formation of new fat, demonstrated in both obese Zucker rats and ob/ob mice.[1]
  • Beta-oxidation: Increases fatty acid oxidation, shifting metabolism toward fat utilization.
  • Beta-3 adrenergic receptor: AOD-9604's lipolytic effects are not directly mediated through the beta-3 adrenergic receptor, though both AOD-9604 and hGH increase beta-3 AR expression.[2]
  • Metabolic selectivity: Does not activate the GH receptor's somatogenic (growth-promoting) pathway. Does not increase IGF-1, insulin, thyroid hormones, cortisol, testosterone, or estrogen.[6]
  • Disulfide bond: Contains a disulfide bond between the two cysteine residues (positions 182 and 189 in the GH sequence), important for structural stability and biological activity.

How it differs from related compounds:

  • vs. Full-length growth hormone (somatropin): GH promotes both lipolysis AND tissue growth, raises IGF-1, and can cause insulin resistance. AOD-9604 isolates only the lipolytic activity.
  • vs. hGH Fragment 176-191 (without tyrosine): The native fragment lacks the N-terminal tyrosine; AOD-9604's tyrosine addition improves stability and potentially oral bioavailability.
  • vs. Tesamorelin: Tesamorelin is a GHRH analog that raises GH (and thus IGF-1). AOD-9604 does not raise GH or IGF-1.
  • vs. Semaglutide/tirzepatide: GLP-1 receptor agonists work through entirely different mechanisms (appetite suppression, gastric slowing) and have extensive Phase III evidence proving efficacy. AOD-9604 failed where these compounds succeeded.

What the research says

AOD-9604 is a rare case where the clinical story is clear — and negative. It has an excellent safety profile from 900+ human participants. But it failed its pivotal Phase IIb trial for weight loss. Everything marketed about this compound should be read in that context.

Peptide Garden evidence assessment, March 2026

Research timeline

AOD-9604 has a more complete clinical history than most research peptides — which makes the gap between marketing claims and actual evidence especially notable:

  1. 1997Preclinical

    Fragment identified at Monash University

    Professor Frank Ng's laboratory identifies the C-terminal fragment (177-191) of growth hormone as responsible for lipolytic activity. Tyrosine added at N-terminus for stability.

  2. 2000Preclinical

    Animal studies show fat reduction

    Obese Zucker rats treated with oral AOD-9604 showed over 50% reduction in body weight gain. Fat mass decreased without affecting lean mass.

  3. 2001Preclinical

    Mechanism studies published

    Heffernan et al. demonstrate that AOD-9604 reduces body fat through lipolysis stimulation and lipogenesis inhibition, independent of the beta-3 adrenergic receptor.

  4. 2004Human study

    Phase IIa shows modest weight loss

    ~300 obese adults, 12 weeks oral dosing. AOD-9604 group lost 2.6 kg vs 0.8 kg placebo. Statistically significant. Metabolic Pharmaceuticals hails it as a success.

  5. 2006Human study

    Phase IIb (OPTIONS) enrolls 536 subjects

    Largest-ever trial of AOD-9604. 24 weeks, three oral doses (0.25, 0.5, 1 mg/day), randomized, double-blind, placebo-controlled.

  6. 2007Human study

    Phase IIb FAILS primary endpoint

    OPTIONS Study does not meet its primary endpoint. No statistically significant weight loss vs placebo at 24 weeks. Metabolic Pharmaceuticals terminates development. This is the pivotal result.

  7. 2009Regulatory

    IP transferred after company restructure

    Metabolic Pharmaceuticals restructures. AOD-9604 intellectual property transfers to Calzada, then PolyNovo Biomaterials, then Lateral Pharmaceuticals (redesignated LAT8881).

  8. 2013Regulatory

    Safety data published + WADA statement

    Stier et al. publish pooled safety analysis of 6 trials (900+ participants): safety profile indistinguishable from placebo. WADA issues clarifying statement confirming AOD-9604 is prohibited under S0.

  9. 2015Preclinical

    Rabbit joint study published

    Kwon et al. show AOD-9604 enhances cartilage regeneration in a rabbit osteoarthritis model. First and only study supporting joint health claims.

  10. 2023Regulatory

    FDA places AOD-9604 on Category 2 list

    FDA classifies AOD-9604 as a Category 2 bulk drug substance, effectively banning compounding.

  11. 2024Regulatory

    Removed from Category 2; PCAC votes against 503A

    September: FDA removes AOD-9604 from Category 2 after nominator withdraws. December: PCAC votes against recommending AOD-9604 for the 503A bulks list. FDA cites lack of injectable safety data and immunogenicity concerns.

  12. 2026Regulatory

    Kennedy reclassification pending

    HHS Secretary Kennedy announces intention to reclassify ~14 peptides including AOD-9604 to Category 1. No formal rule change published as of March 2026.

Human clinical trials

AOD-9604 has more human clinical data than most research peptides — which makes the evidence picture both clearer and more sobering. Six controlled trials were conducted with 900+ total participants. Here are the key results:

2004·Randomized, double-blind, placebo-controlled·n=300Moderate quality

Phase IIa oral AOD-9604 for obesity

Obesity (weight loss)

12-week oral dosing showed modest weight reduction: 2.6 kg vs 0.8 kg placebo. Statistically significant but clinically modest. This result is frequently cited in marketing — the Phase IIb failure that followed is not.

2007·Randomized, double-blind, placebo-controlled·n=536Moderate quality

OPTIONS Study — Phase IIb oral AOD-9604 for obesity

Obesity (weight loss)

24-week trial at oral doses of 0.25, 0.5, and 1 mg/day. Primary endpoint NOT met — no statistically significant weight loss difference vs placebo. This is the largest and most rigorous trial. Development was terminated.

2013·Pooled analysis of 6 RCTs·n=900Moderate quality

Safety and tolerability across 6 controlled trials

Safety and tolerability

AOD-9604 displayed a safety profile indistinguishable from placebo. No effect on IGF-1, no negative effect on carbohydrate metabolism, no anti-AOD-9604 antibodies formed.

The marketing gap you should know about: AOD-9604 is frequently promoted as a "proven fat-loss peptide" based on the Phase IIa result (2.6 kg loss over 12 weeks). What these claims consistently omit is that the larger, longer, more rigorous Phase IIb trial failed. The 12-week signal did not hold up at 24 weeks with more participants. This is the single most important fact about AOD-9604 as a weight loss compound.

The injectable question

There is another critical fact that is almost never disclosed in marketing: all human clinical trials of AOD-9604 used oral dosing. The injectable subcutaneous form — which is what most clinics have sold and most consumers have used — was never tested in a published human trial.

This means we have no controlled human data on:

  • Whether injectable AOD-9604 produces different effects than oral
  • What the appropriate injectable dose is
  • Whether the pharmacokinetics differ by route
  • Whether the safety profile changes with subcutaneous administration

The oral form was tested, and it failed for efficacy. The injectable form was never tested at all.

Animal studies

The preclinical evidence is where AOD-9604 looked most promising. Multiple studies from Monash University showed significant fat reduction in obese animal models:[2]

Key findings from animal research
  • Obese Zucker rats: Oral AOD-9604 for 19 days reduced body weight gain by over 50% and increased lipolytic activity in adipose tissue.[3]
  • ob/ob mice: Chronic administration reduced fat mass without affecting lean mass, increased fat oxidation, and stimulated lipolysis.
  • Beta-3 AR knock-out mice: AOD-9604's lipolytic effects were preserved even in mice lacking the beta-3 adrenergic receptor, demonstrating an independent mechanism.[2]
  • Cartilage repair (rabbits): Intra-articular injections enhanced cartilage regeneration in a collagenase-induced osteoarthritis model. Combined AOD-9604 + hyaluronic acid was more effective than either alone.[8]
  • No diabetogenic effects: Unlike full-length GH, AOD-9604 did not cause insulin resistance or glucose intolerance in any animal model.

When animal results don't translate: The fat-loss effects in rodent models were clear and consistent. But this is precisely the kind of result that sometimes fails to replicate in humans — different metabolism, different pharmacokinetics, different context. With AOD-9604, that's exactly what happened. The animal data was promising; the human data was not.


What the evidence shows

People come to AOD-9604 with specific expectations — usually about fat loss. Here's what the published research actually tells us about each major claim:

Does AOD-9604 cause fat loss or weight reduction?

This is the most commonly exaggerated claim. A 12-week Phase IIa trial showed modest weight loss (2.6 kg vs 0.8 kg). However, the larger, longer Phase IIb trial (OPTIONS, n=536, 24 weeks) failed to meet its primary endpoint — no statistically significant weight loss vs placebo. Development was abandoned. Marketing materials almost universally cite the Phase IIa result while omitting the Phase IIb failure.

Not yet demonstrated

Does AOD-9604 avoid the side effects of growth hormone (no IGF-1 increase)?

Consistently demonstrated across multiple human trials. AOD-9604 does not increase IGF-1 levels, does not affect glucose homeostasis, and does not promote tissue growth. This metabolic selectivity is the compound's genuine scientific contribution.

Well-supported

Does AOD-9604 avoid glucose disruption?

Confirmed across multiple trials. Oral glucose tolerance tests demonstrated no negative effect on carbohydrate metabolism, in contrast with full-length growth hormone. This is well-established.

Well-supported

Does AOD-9604 help with joint health or cartilage repair?

One animal study (rabbits, n=32) showed enhanced cartilage regeneration with intra-articular AOD-9604 injections. In vitro data suggests proteoglycan and collagen production in chondrocytes. No human trials for this indication exist. This is very preliminary evidence being marketed as if it were established.

More research needed

Safety & side effects

What research shows

This is where AOD-9604 genuinely distinguishes itself. The safety data is the strongest part of the evidence profile — and it comes from real clinical trials with hundreds of participants.[6]

Across 6 randomized, double-blind, placebo-controlled trials involving more than 900 participants:

  • No serious adverse events attributable to AOD-9604 in any trial
  • No anti-AOD-9604 antibody formation in any participant
  • No glucose intolerance or insulin resistance (confirmed by oral glucose tolerance tests)
  • No IGF-1 elevation
  • No hormonal disruption of any kind — testosterone, estrogen, cortisol, thyroid hormones all unaffected
  • Safety profile described as "indistinguishable from placebo" in the Phase IIb trial

The most commonly reported adverse events were mild and occurred at rates similar to placebo: headache, mild facial flushing, and fatigue.[7]

Community-reported side effects

Among people who have used AOD-9604 outside of clinical settings (primarily via subcutaneous injection — a route not tested in clinical trials), commonly reported effects include:

  • Injection-site redness, swelling, or tenderness
  • Mild nausea (infrequent)
  • Mild water retention
  • Headache
  • Stomach discomfort

These are self-reported and not from controlled studies.

Limitations of the safety data

Important context: While the safety record is genuinely excellent, there are limitations. The longest trial was 24 weeks — long-term safety beyond 6 months is unknown. All clinical trials used oral dosing; the injectable form that most people actually use has not been studied in a controlled setting. And compounding quality variability introduces risks unrelated to the compound itself.

Contraindications and interactions

Theoretical contraindications (based on mechanism of action, not clinical data):

  • Active malignancy (theoretical; though AOD-9604 does not raise IGF-1, which reduces this concern compared to full-length GH)
  • Pregnancy and breastfeeding (no safety data)
  • Hypersensitivity to AOD-9604 or related peptides

Drug interactions: No clinically established drug interactions. The compound's lack of hormonal activity makes interactions less likely than with full-length growth hormone. Theoretical caution with other weight-loss agents (additive effects unknown).


How people use it

AOD-9604 has been used primarily in the context of fat loss and, more recently, joint health. Here's what the landscape of use looks like — with important caveats.

Administration routes

  • Subcutaneous injection (most common in practice): Injected in the abdomen, typically in a fasted state. This is the most common route used by clinics and consumers — but it was never tested in the clinical trials, which used oral dosing.
  • Oral capsule/troche: More aligned with the form actually tested in clinical trials, though that form failed for efficacy at the doses tested.

About dosing information: Specific dosing ranges are not published on Peptide Garden pending legal review. No AOD-9604 dosing protocol has been validated for fat loss in a human clinical trial — the pivotal trial failed. If you're considering AOD-9604, the right first step is a conversation with a knowledgeable healthcare provider who can assess your specific situation.

Common stacking context

In clinical and community practice, AOD-9604 has been discussed alongside other compounds:

  • AOD-9604 + CJC-1295/Ipamorelin — sometimes combined for additive fat-loss effects. No evidence for synergy with AOD-9604 specifically.
  • AOD-9604 + BPC-157 — sometimes added for joint health claims. No combination data exists.
  • AOD-9604 + Hyaluronic acid — one rabbit study showed enhanced cartilage regeneration with the combination vs. either alone.[8]

All stacking protocols are practitioner-derived or community-derived and have not been studied in any controlled human setting.

If you plan to reconstitute peptides, see our reconstitution guide for safety-first preparation instructions.


As of March 2026:

FDA status

AOD-9604 is not FDA-approved for any indication in any country. It has a more complex regulatory history than most research peptides:

  • September 2023: FDA classified AOD-9604 as a Category 2 bulk drug substance, effectively banning compounding.[12]
  • September 2024: FDA removed AOD-9604 from Category 2 after the nominator withdrew its nomination.
  • December 4, 2024: The Pharmacy Compounding Advisory Committee (PCAC) voted against recommending AOD-9604 for the 503A bulks list. The FDA briefing document cited lack of safety data for the injectable form and immunogenicity concerns.[10]
  • February 2026: HHS Secretary Kennedy announced that approximately 14 peptides, including AOD-9604, would be reclassified to Category 1.

Where it stands now: The Kennedy reclassification has been announced but has not yet been formally published in the Federal Register. A related lawsuit has been administratively closed pending a final FDA rule expected by March 14, 2027. Reclassification to Category 1 would not constitute FDA approval — it would only permit compounding pharmacies to prepare it with a valid prescription.

WADA / USADA status

AOD-9604 is prohibited at all times under WADA Section S0 (Non-Approved Substances). WADA issued a specific clarifying statement in April 2013 confirming that AOD-9604 is banned, following confusion that arose from an Australian Crime Commission investigation.[11]

International status

AOD-9604 is not approved for clinical use in any country. Development was abandoned in 2007 by Metabolic Pharmaceuticals after the Phase IIb failure. The IP changed hands multiple times (Metabolic Pharmaceuticals to Calzada to PolyNovo to Lateral Pharmaceuticals) and was redesignated LAT8881, but no new human efficacy trials have been conducted.


How AOD-9604 compares

The most instructive comparison is between AOD-9604 — a compound that failed its weight loss trial — and semaglutide, which succeeded:

AOD-9604

Research compound · Failed Phase IIb

Animal evidence50%
Human evidence30%
Safety data60%

Total trials

6

Human subjects

900+

Efficacy result

Failed

First studied

1997

Semaglutide

FDA-approved · Proven weight loss

Animal evidence90%
Human evidence95%
Safety data92%

Total trials

100+

Human subjects

17,000+

Efficacy result

Proven

First studied

2012

The contrast is stark and instructive. AOD-9604 was tested in 900+ participants and failed its primary efficacy endpoint. Semaglutide was tested in 17,000+ participants and achieved FDA approval for both diabetes and obesity, with weight loss of 15-20% of body weight in clinical trials.

If you're considering a peptide for weight management, this comparison matters. One compound has proven efficacy data; the other does not. AOD-9604's genuine advantage — metabolic selectivity without hormonal side effects — is real but does not compensate for the lack of proven weight loss.



References

  1. [1]
    Heffernan MA, Jiang WJ, Thorburn AW, Ng FM. Effects of oral administration of a synthetic fragment of human growth hormone on lipid metabolism.” Am J Physiol Endocrinol Metab. 2001. 281(5):E1049–E1057 DOI PubMedAnimal study

    Foundational study from Monash University demonstrating AOD-9604's lipolytic effects in obese Zucker rats.

  2. [2]
    Heffernan MA, Summers RJ, Thorburn A, Ogru E, Gianello R, Jiang WJ, Ng FM. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice.” Endocrinology. 2001. 142(12):5182–5189 DOI PubMedAnimal study

    Demonstrated that AOD-9604 reduces body fat through mechanisms independent of the beta-3 adrenergic receptor.

  3. [3]
    Ng FM, Sun J, Sharma L, Libinaka R, Jiang WJ, Gianello R. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone.” Horm Res. 2000. 53(6):274–278 DOI PubMedAnimal study

    Early Monash University study showing AOD-9604 reduced body weight gain by over 50% in obese Zucker rats over 19 days of oral treatment.

  4. [4]
    Metabolic Pharmaceuticals Ltd. Phase IIa clinical trial of oral AOD-9604 for obesity.” 2004. Link

    12-week RCT in ~300 obese adults. Modest weight loss (2.6 kg vs 0.8 kg placebo). Results never published in a peer-reviewed journal — only in press releases.

  5. [5]
    Metabolic Pharmaceuticals Ltd. OPTIONS Study: Phase IIb clinical trial of oral AOD-9604 for obesity.” 2007. Link

    24-week RCT in 536 obese adults. Primary endpoint NOT met. No statistically significant weight loss vs placebo. Development terminated. Results never published in a peer-reviewed journal.

  6. [6]
    Stier H, Vos E, Kenley D. Safety and tolerability of the hexadecapeptide AOD9604 in humans.” J Endocrinol Metab. 2013. 3(1-2):7–15 DOISafety study

    Pooled safety analysis of 6 randomized, double-blind, placebo-controlled trials (900+ participants). Safety profile indistinguishable from placebo.

  7. [7]
    More MI, Kenley D, Gianello R. Safety and metabolism of AOD9604, a novel nutraceutical ingredient for improved metabolic health.” J Endocrinol Metab. 2014. 4(3):68–78 DOISafety study

    Confirmed safety of nutraceutical-grade AOD-9604 in animal toxicology studies. No genotoxic activity in Ames test, chromosomal aberration assay, or bone micronucleus assay.

  8. [8]
    Kwon DR, Park GY, Lee SC. Effect of intra-articular injection of AOD9604 with or without hyaluronic acid in rabbit osteoarthritis model.” Ann Clin Lab Sci. 2015. 45(4):426–432 PubMedAnimal study

    Rabbit model (n=32). AOD-9604 enhanced cartilage regeneration; combination with HA was more effective. Single animal study, no human follow-up.

  9. [9]
    Kok P, Roelfsema F, Frolich M, van Pelt J, Meinders AE, Pijl H. Obesity pharmacotherapy: current perspectives and future directions.” Curr Pharm Des. 2003. 9(15):1235–1253 PubMedReview

    Review of obesity pharmacotherapy placing AOD-9604 in the broader landscape of weight-loss drug development.

  10. [10]
    U.S. Food and Drug Administration. FDA Briefing Document: Pharmacy Compounding Advisory Committee (PCAC) Meeting — AOD-9604, December 4, 2024.” 2024. Link

    PCAC voted against recommending AOD-9604 for the 503A bulks list. FDA cited lack of safety data for injectable form and immunogenicity concerns.

  11. [11]
    World Anti-Doping Agency. WADA statement on substance AOD-9604.” 2013. Link
  12. [12]
    U.S. Food and Drug Administration. Certain bulk drug substances that may present significant safety risks under conditions of use in compounding.” 2023. Link

Medical disclaimer

Peptide Garden is an educational resource, not a medical provider. The information on this page is compiled from published research and is intended for informational purposes only. It does not constitute medical advice, diagnosis, or treatment recommendations. AOD-9604 is not FDA-approved for any indication. Its pivotal Phase IIb trial for weight loss failed. Always consult a qualified healthcare provider before making decisions about peptide therapy.