Dr. Pep

Peptides · Growth hormone fragment (Tyr-hGH 177-191)

AOD-9604: what the studies show

Every line below comes from a study, label or regulator record, checked by two models, with the source linked. Information, not medical advice. For adults 18+.

What it is

  • AOD-9604 is a lab-made peptide based on the tail end of human growth hormone (amino acids 177-191, with an extra tyrosine at the start). It was designed to keep growth hormone's fat-burning signal without its effects on blood sugar and growth.[1][2]
  • It is not growth hormone and does not bind the growth hormone receptor in lab tests. In obese mice it did not raise blood sugar the way full-length growth hormone did.[3][2]

Bottom line

  • AOD-9604 was developed as an oral obesity drug. In the one human weight-loss study described in the records it did not beat placebo on the main endpoint, and the evidence for fat loss rests on rodent studies from the 1990s and 2000s. It is not approved, and FDA's advisory committee voted 0 to 12 against letting pharmacists compound it.[2][4][5]

What the human studies found

  • A 2026 narrative review says human data are limited and short. In a 24-week study of AOD-9604 as an oral anti-obesity drug (534 enrolled, 502 randomised), it did not show a significant benefit on the main weight-loss endpoint. The review says this conclusion rests mostly on sponsor-reported phase 2 results, not peer-reviewed randomised trials.[2]
  • The company-development summary from 2004 says phase IIa trials were under way by February 2002. It gives no results.[6]
  • No human trial of AOD-9604 for joint, cartilage or muscle repair, the use it is often promoted for online, is in these records. FDA's committee evaluated it only for obesity.[5][2]

Known risks and side effects

  • FDA's category 2 page says compounded AOD-9604 may carry a significant risk of immune reactions for some routes, and that peptide impurities and difficulty characterising the ingredient add risk. FDA found no, or only limited, safety information and said it has identified serious adverse events that may be associated with AOD-9604, though causality is not clear.[7]
  • At FDA's December 2024 compounding advisory committee meeting, FDA staff summarised a report of six placebo-controlled studies of IV and oral AOD-9604, funded by the developer (Metabolic Pharma). The authors concluded the safety profile was comparable in all groups, with no significant changes in lab tests, ECG, vital signs or IGF-1, and no antibodies found in selected people given oral doses for up to 24 weeks. FDA noted the studies lacked detailed side-effect breakdowns and were short.[8]
  • A 2026 review of growth-hormone-axis peptides sold as 'research compounds' lists reported side effects for the group as a whole: raised prolactin and cortisol, appetite changes, blood sugar changes, fluid retention, joint and muscle pain, and injection-site reactions. It cannot say which compound caused which effect.[2]

Legal status

  • AOD-9604 is not an approved drug. FDA's category 2 page lists it under bulk substances nominated but withdrawn, which FDA says may pose significant safety risks if compounded.[7]
  • On 2024-12-04 FDA's Pharmacy Compounding Advisory Committee considered AOD-9604 (free base and acetate) for the 503A bulks list for obesity. Members voted 12 to 0 to use a single vote, then 0 yes and 12 no on whether to place it on the list. The vote is advisory.[5][9]
  • A 2015 analytical paper states AOD-9604 is banned by the World Anti-Doping Agency and was found in confiscated vials in the USA.[1]

Sources

  1. [1] Detection and in vitro metabolism of AOD9604.
  2. [2] The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration.
  3. [3] Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragment.
  4. [4] Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone.
  5. [5] FDA: Final Summary Minutes of the Pharmacy Compounding Advisory Committee Meeting (2024-12-04), CJC-1295, AOD-9604, thymosin alpha-1
  6. [6] AOD-9604 Metabolic.
  7. [7] FDA: Certain bulk drug substances for use in compounding that may present significant safety risks (503A/503B category 2)
  8. [8] FDA: PCAC Topic 1 transcript, CJC-1295 and AOD-9604 (2024-12-04)
  9. [9] FDA: PCAC Briefing Document (2024-12-04), CJC-1295, AOD-9604, thymosin alpha-1