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Comparison

AOD-9604 vs HGH Fragment 176-191

AOD-9604 is fat loss; HGH Fragment 176-191 is IGF & growth factors. They are compared here because they are frequently considered against each other, not because they act alike.

On published evidence alone, AOD-9604 is the better documented of the two (clinical trials). That is a statement about the state of the literature, not a recommendation.

AOD-9604 HGH Fragment 176-191
Class Fat loss IGF & growth factors
Evidence Clinical trials Preliminary human
Human trials ~6 ~3
Half-life ~30 minutes ~30 minutes
Reported range 300-600 mcg 250-500 mcg
Frequency Once daily, fasted 1-2x daily, fasted
Routes Subcutaneous, Oral Subcutaneous
FDA approved No No
Research use only Yes Yes
Banned in sport Yes Yes
Studied for Fat loss research, Investigated for osteoarthritis Fat loss research, Body composition
Reported side effects Injection-site reactions, Headache, Transient fatigue Injection-site reactions, Headache, Transient fatigue

AOD-9604

AOD-9604 is the hGH 177-191 fragment with an added N-terminal tyrosine for stability. In preclinical models it increased lipolysis and inhibited lipogenesis without affecting IGF-1 or glucose metabolism, which made it an attractive obesity candidate. The phase IIb trial in obese adults did not separate from placebo on weight loss, and development for that indication was discontinued. It is worth stating plainly because the compound is still marketed on the strength of the preclinical data.

HGH Fragment 176-191

This 16-residue fragment corresponds to the C-terminus of human growth hormone and reproduces the lipolytic and anti-lipogenic activity of the full molecule. Because it lacks the regions responsible for receptor-mediated growth signalling, it does not raise IGF-1 or produce the glucose intolerance associated with exogenous hGH. Human data for the fragment itself is thin, and the best-studied derivative is AOD-9604, which failed to separate from placebo on weight loss in its phase IIb trial.

AOD-9604 vs HGH Fragment 176-191: common questions

What is the difference between AOD-9604 and HGH Fragment 176-191?

AOD-9604 is fat loss and HGH Fragment 176-191 is IGF & growth factors, so they act on different pathways. AOD-9604: A modified growth hormone fragment developed specifically as an obesity drug, which failed to beat placebo in phase IIb. HGH Fragment 176-191: The C-terminal fragment of human growth hormone that carries its fat-metabolising activity without the growth-promoting portion.

Which has stronger evidence, AOD-9604 or HGH Fragment 176-191?

AOD-9604 has the stronger evidence base (clinical trials, about 6 human studies) compared with HGH Fragment 176-191 (preliminary human).

Are AOD-9604 and HGH Fragment 176-191 FDA approved?

Neither is FDA approved for any indication.

References

Regulatory and primary sources

  1. PubChem compound record (CID 71300630) ↗ · structure, identifiers, synonyms
  2. WADA Prohibited List ↗ · current year
  3. FDA: Unapproved drugs and "research use only" products ↗ · regulatory status of non-approved products
  4. CAS Registry Number 221231-10-3 ↗ · chemical identity
  5. PubChem compound record (CID 172966176) ↗ · structure, identifiers, synonyms
  6. CAS Registry Number 66004-57-7 ↗ · chemical identity

Published literature

  1. Wilding J. AOD-9604 Metabolic.Curr Opin Investig Drugs 2004.PubMed 15134286
  2. Rahman OF, Lee SJ, Seeds WA. Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.J Am Acad Orthop Surg Glob Res Rev 2026.PubMed 41490200 · doi:10.5435/JAAOSGlobal-D-25-00236
  3. Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.Sports Med 2026.PubMed 41966639 · doi:10.1007/s40279-026-02437-0
  4. Halford JC. Obesity drugs in clinical development.Curr Opin Investig Drugs 2006.PubMed 16625817
  5. Thevis M, Schänzer W. Analytical approaches for the detection of emerging therapeutics and non-approved drugs in human doping controls.J Pharm Biomed Anal 2014.PubMed 24906629 · doi:10.1016/j.jpba.2014.05.020
  6. Jensen MD. Potential role of new therapies in modifying cardiovascular risk in overweight patients with metabolic risk factors.Obesity (Silver Spring) 2006.PubMed 16931496 · doi:10.1038/oby.2006.294
  7. Khan A, Raza S, Khan Y, et al.. Current updates in the medical management of obesity.Recent Pat Endocr Metab Immune Drug Discov 2012.PubMed 22435392 · doi:10.2174/187221412800604644
  8. Zieba R. [Obesity: a review of currently used antiobesity drugs and new compounds in clinical development].Postepy Hig Med Dosw (Online) 2007.PubMed 17971763

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.

Read this first This page compares published reference data. It is not medical advice and not a recommendation to use either compound. Several compounds documented on this site are not approved for human use.