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AMIRAVOResearch Library

AOD-9604 vs HGH Fragment 176-191

AOD-9604 and HGH Fragment 176-191 are closely related synthetic peptides from the C-terminal end of human growth hormone, and the names are sometimes used interchangeably 1. AOD-9604 is described as hGH residues 177-191 with an extra tyrosine at the N-terminus, whereas the PubChem record for HGH Fragment 176-191 begins with phenylalanine 2,3,4. Neither has an FDA-approved application, and WADA names both as prohibited growth hormone fragments 5,6,7.

Unbranded reference vial illustrating AOD-9604; not an actual product
AOD-9604
Not approved — research use only
Unbranded reference vial illustrating HGH Fragment 176-191; not an actual product
HGH Fragment 176-191
Not approved — research use only

Side by side

FieldAOD-9604HGH Fragment 176-191
ClassSynthetic C-terminal fragment analogue of human growth hormone 2Synthetic C-terminal fragment of human growth hormone (residues 176-191) 8
Origin and structurehGH 177-191 with an additional N-terminal tyrosine; PubChem formula C78H123N23O23S2 2,3PubChem record (acetate form) with an N-terminal phenylalanine and formula C80H127N23O24S2 including acetic acid 4; the shared 177-191 sequence is Leu-Arg-Ile-Val-Gln-Cys-Arg-Val-Ser-Glu-Gly-Ser-Cys-Gly-Phe 9
Proposed mechanismIn obese mice (animal data), reduced body weight and fat and raised beta-3 adrenergic receptor expression, though its lipolytic action was not mediated directly through that receptor 10; reported to show no GH receptor binding in vitro 1In 1970s rat studies (animal data), hGH 176-191 produced a short-lived rise in blood glucose and a more sustained rise in insulin 8; the 177-191 sequence showed antilipogenic but not lipolytic activity in rat fat tissue 9
Half-lifeNot reported in human trials, according to a 2026 review 1; a stable metabolite was identified in serum in vitro 2Not located in the sources reviewed
Highest human trial phasePhase 2 (sponsor-reported); phase IIa trials were under way by 2002 1,11; no ClinicalTrials.gov records found 12No human trials located; no ClinicalTrials.gov records found 13
FDA statusNot approved; no Drugs@FDA record as of 24 October 2026 5; listed by FDA among bulk substances previously in compounding category 2 whose nominations were withdrawn, citing immunogenicity and limited safety information (content current 22 April 2026) 14Not approved; no Drugs@FDA record as of 24 October 2026 6; not named on FDA's category 2 page or the 503A nominations list reviewed 14,15
Published human outcomesA 24-week oral study (502 randomized) did not show a significant effect on its primary body-weight endpoint; a 2026 review notes this rests mainly on sponsor-reported outcomes 1None located
Safety signalsFDA notes serious adverse events that may be associated with AOD-9604, though causality is not clear 14; in obese rats it did not impair insulin sensitivity, unlike intact hGH (animal data) 16No human safety data located; in rats, fragments containing residues 178-191 reduced insulin sensitivity (animal data) 8
WADA statusNamed in S2.2.3 as a growth hormone fragment; prohibited at all times; non-specified 7Named in S2.2.3 as a growth hormone fragment ("hGH 176-191"); prohibited at all times; non-specified 7
Who funded the evidenceHuman programme developed by Metabolic Pharmaceuticals, with efficacy conclusions based on sponsor reports 1,11; funders of animal studies not locatedNot located in the sources reviewed

AOD-9604: what the data says

AOD-9604 was developed as a candidate obesity drug intended to keep growth hormone's fat-metabolism effects without its growth effects 1.

  • In obese mice (animal data), longer-term treatment reduced body weight and body fat, and in an acute experiment raised energy expenditure and fat oxidation even in mice lacking the beta-3 adrenergic receptor 10.
  • In obese Zucker rats (animal data), oral treatment reduced body-weight gain by more than half compared with controls, without the loss of insulin sensitivity seen with intact hGH 16.
  • In humans, a 2026 review reports that a 24-week oral study did not show a significant effect on the primary body-weight endpoint, and rates the human evidence as limited 1.
  • Claims about joint or cartilage repair rest mainly on a rabbit osteoarthritis model (animal data) 1.

HGH Fragment 176-191: what the data says

Published work on the 176-191 fragment itself is sparse and mostly preclinical 8,17.

  • In normal rats (animal data), synthetic hGH 176-191 caused a short-lived rise in blood glucose and a sustained rise in plasma insulin 8.
  • In MCF-7 breast cancer cells (cell data), adding the fragment to doxorubicin-loaded chitosan nanoparticles increased antiproliferative activity compared with doxorubicin nanoparticles alone 17.
  • No registered or published human trials of hGH 176-191 were located 13.

Key research differences

  • N-terminal residue: AOD-9604 carries tyrosine before the 177-191 sequence, while the PubChem record for HGH Fragment 176-191 carries phenylalanine 2,3,4.
  • Human testing: AOD-9604 reached sponsor-run phase 2 trials, whereas no human trials of hGH 176-191 were located 1,11,13.
  • Glucose findings in rats: hGH 176-191 raised blood glucose and insulin in a 1978 study, whereas AOD-9604 did not impair insulin sensitivity in a 2000 study; the designs differed (animal data) 8,16.
  • FDA compounding review: FDA's category 2 page names AOD-9604 (in its withdrawn-nominations list), but not hGH 176-191 14.
  • Anti-doping: no difference; WADA's 2026 List names both as growth hormone fragments under S2.2.3 7.

Where the evidence is limited

There is no head-to-head study of the two peptides in any model. Most data are from rats, mice or cells, and the only human efficacy data for AOD-9604 are described as sponsor-reported rather than peer-reviewed 1,8,10. Because the names are used loosely, products and papers labelled with either name may not contain the same molecule 1.

Frequently asked questions

Are AOD-9604 and HGH Fragment 176-191 the same thing?
Not exactly. AOD-9604 is hGH 177-191 with an added N-terminal tyrosine, while the PubChem record for HGH Fragment 176-191 starts with phenylalanine; a 2026 review notes AOD-9604 is sometimes labelled hGH 176-191 1,2,4.
Have AOD-9604 or HGH Fragment 176-191 been tested in humans?
AOD-9604 was tested in sponsor-run trials, including a 24-week oral study that did not meet its primary body-weight endpoint 1. No human trials of hGH 176-191 were located 13.
Are they banned in sport?
Yes. The WADA 2026 Prohibited List names AOD-9604 and hGH 176-191 under S2.2.3 growth hormone fragments, prohibited at all times 7.
Are they FDA-approved?
No. Neither returned a Drugs@FDA application record on 24 October 2026 5,6.

References

  1. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration (full text) Front Endocrinol (Lausanne). 2026
  2. Detection and in vitro metabolism of AOD9604 Drug Test Anal. 2015
  3. PubChem compound record for AOD-9604 (CID 71300630): molecular formula C78H123N23O23S2, IUPAC name and synonyms PubChem. 2026
  4. PubChem compound record for HGH Fragment 176-191 (CID 172966176, acetate): molecular formula C80H127N23O24S2 and IUPAC name PubChem. 2026
  5. Drugs@FDA application data queried through openFDA for AOD-9604 (no matching application record returned on 24 October 2026) openFDA / Drugs@FDA. 2026
  6. Drugs@FDA application data queried through openFDA for "hGH 176-191" (no matching application record returned on 24 October 2026) openFDA / Drugs@FDA. 2026
  7. The 2026 Prohibited List - World Anti-Doping Code, as published in the Netherlands Treaty Series (Tractatenblad 2026, 25; Council of Europe Anti-Doping Convention appendix, in force 1 January 2026) Tractatenblad (Official Publications of the Kingdom of the Netherlands). 2026
  8. Hyperglycemic action of synthetic C-terminal fragments of human growth hormone Am J Physiol. 1978
  9. Antilipogenic action of synthetic C-terminal sequence 177-191 of human growth hormone Biochem Mol Biol Int. 1993
  10. 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
  11. AOD-9604 Metabolic Curr Opin Investig Drugs. 2004
  12. ClinicalTrials.gov registry search for AOD9604 OR AOD-9604 as intervention (0 records; retrieved 24 October 2026) ClinicalTrials.gov. 2026
  13. ClinicalTrials.gov registry search for growth hormone fragment 176-191 as intervention (0 records; retrieved 24 October 2026) ClinicalTrials.gov. 2026
  14. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (content current as of 04/22/2026) FDA (Human Drug Compounding). 2026
  15. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (updated May 14, 2026) FDA. 2026
  16. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone Horm Res. 2000
  17. Human Growth Hormone Fragment 176-191 Peptide Enhances the Toxicity of Doxorubicin-Loaded Chitosan Nanoparticles Against MCF-7 Breast Cancer Cells Drug Des Devel Ther. 2022

For research use only. Not for human or veterinary use. Not a drug, food, or dietary supplement. This page compares published research and is not medical advice or a recommendation.