AOD9604
AOD9604 (Tyr-hGH 177-191, Anti-Obesity Drug 9604)
What is AOD9604?
AOD9604: Modified C-terminal fragment of human growth hormone (Tyr-hGH 177-191) designed to keep GH's fat-burning activity without IGF-1/glucose effects. The sources cited here most often discuss it for: Fat loss, failed in trials; Cartilage repair, animal; Well tolerated in trials. Evidence label: Trial-backed.
- Type
- Peptide
- Family
- Weight & Metabolic
- Evidence label
- Trial-backed (4 of 5)
- Regulatory status
- FDA listed AOD-9604 among nominated compounding substances that may present significant safety risks, citing immunogenicity and serious adverse events of unclear causality, and the nomination was later withdrawn.
- Goals discussed
- Fat Loss & Metabolism, Healing & Recovery
- Also called
- AOD-9604, Tyr-hGH177-191, Anti-Obesity Drug 9604, HGH fragment 177-191, AOD
- Last reviewed
- 2026-10-11
- Modified C-terminal fragment of human growth hormone (Tyr-hGH 177-191) designed to keep GH's fat-burning activity without IGF-1/glucose effects; failed as an obesity drug, not FDA-approved (had food-ingredient GRAS-type nutraceutical positioning).1
AOD9604 is the hGH 177-191 fragment with an added tyrosine; it is often confused with HGH Fragment 176-191, which Seek Peptides lists as a separate peptide.
Regulatory status FDA listed AOD-9604 among nominated compounding substances that may present significant safety risks, citing immunogenicity and serious adverse events of unclear causality, and the nomination was later withdrawn. 2
Names as used in gyms, forums and gray-market listings. Reported, not endorsed; stacks have not been studied as combinations.
FDA has also identified serious adverse events that may be associated with AOD-9604, though causality is not clear.
FDA's safety assessment of AOD-9604 as a nominated compounding substance; the nomination was later withdrawn.
What is AOD9604 researched for?
The three outcomes most discussed for AOD9604 in the sources below, as those sources report them. humanpeptides.fyi makes no claims of its own: a listed benefit can be unproven or can have failed in trials, and the label on each line says which.
Well tolerated in trials
- Good safety/tolerability: across 6 RCTs (~900 people) no IGF-1 rise, no impaired glucose tolerance, no antibodies, safety indistinguishable from placebohuman RCT safety data8
What do researchers and users say about AOD9604?
Weight loss at the primary and secondary endpoints of 12 or 24 weeks of treatment, after allowing for the effects of the diet and exercise programme, was less than 1 kg in all dose groups.
Developer's announcement of its 536-person phase 2b obesity trial, after which the obesity program was terminated.
AOD9604 displayed a very good safety and tolerability profile indistinguishable from placebo.
Summary of six randomized placebo-controlled trials; two authors were affiliated with the developer, Metabolic Pharmaceuticals.
What side effects of AOD9604 are reported?
- Mild headache (most common in IV study) and mild GI symptoms; no treatment-related serious adverse eventshuman RCTs1
- Possible immune reactions (immunogenicity) from peptide impurities or characterization problems in compounded products, with little human safety information availableFDA assessment2
- Serious adverse events that may be associated with AOD-9604, causality unclearFDA assessment2
What do peptide guides say about AOD9604?
- Dr. Axe Dr. Axe's guide lists AOD-9604 as research-only and not FDA-approved, noting that the obesity studies FDA assessed did not establish that it works for weight reduction. 9
- PepEdHub PepEdHub describes AOD-9604 as hGH amino acids 177-191 plus an added tyrosine, said to keep growth hormone's fat-reducing activity without growth or blood-sugar effects, via a beta-3 adrenergic pathway. 10
- Seek Peptides Seek Peptides markets AOD-9604 for stubborn-area fat loss as an alternative to full growth hormone, and lists it separately from HGH Fragment 176-191. 11
What does the research say, system by system?
Body & tissues2
Hormones & physiology1
- Does not raise serum IGF-1 and has no negative effect on carbohydrate metabolism, unlike full hGHhuman RCTs8
Weight & metabolism1
- Phase IIb (n=536, 24 wk) weight loss too small to reach significance vs placebo; obesity program terminatedhuman RCT3
Muscle1
- No direct data identified (does not act via IGF-1, so not expected to be anabolic)8
Also notable1
- Non-clinical tox: no genotoxicity in Ames, chromosomal aberration or micronucleus tests; oral absorption with rapid degradationanimal/in vitro4
How strong is the evidence for AOD9604?
Human RCTs exist: safe but failed for weight loss; joint benefit only in animals
Larger randomized human trials exist, positive or negative, but no US approval for the uses discussed. How tiers work
Questions about AOD9604
What is AOD9604?
Modified C-terminal fragment of human growth hormone (Tyr-hGH 177-191) designed to keep GH's fat-burning activity without IGF-1/glucose effects. AOD9604 is the hGH 177-191 fragment with an added tyrosine; it is often confused with HGH Fragment 176-191, which Seek Peptides lists as a separate peptide.
Is AOD9604 FDA-approved?
FDA listed AOD-9604 among nominated compounding substances that may present significant safety risks, citing immunogenicity and serious adverse events of unclear causality, and the nomination was later withdrawn.
What is AOD9604 researched for?
The sources cited on this page most often discuss three outcomes: Fat loss, failed in trials; Cartilage repair, animal; Well tolerated in trials. Each line above shows what the source reports and how strong that evidence is.
What side effects of AOD9604 are reported?
Reported in the cited sources: Mild headache (most common in IV study) and mild GI symptoms; no treatment-related serious adverse events; Possible immune reactions (immunogenicity) from peptide impurities or characterization problems in compounded products, with little human safety information available; Serious adverse events that may be associated with AOD-9604, causality unclear. The list is not complete, and few listed risks does not mean a compound is safe.
How strong is the evidence for AOD9604?
Evidence label: Trial-backed. Human RCTs exist: safe but failed for weight loss; joint benefit only in animals.
What else is AOD9604 called?
Names used for it include AOD-9604, Tyr-hGH177-191, Anti-Obesity Drug 9604, HGH fragment 177-191, AOD.
Does humanpeptides.fyi recommend AOD9604?
No. humanpeptides.fyi makes no claims and no recommendations of its own. It summarizes and links to what others have published and posted. Nothing here is medical advice; talk to a licensed clinician.