Bottom line
A boundary-case entry: AOD-9604 and HGH Fragment 176-191 are not a "blend" of distinct peptides but two variant forms of the same C-terminal fragment of human growth hormone, often confused or marketed interchangeably. AOD-9604 (Tyr-hGH 177-191) is a pharmaceutical optimisation with published Phase II human data; HGH Fragment 176-191 is the unmodified native sequence with no independent human trial data.
No established or recommended human dose.
Name and formulation variability
| Observed market context | Exact material claimed | Identity relevance | Verification limits |
|---|---|---|---|
| Paired market claims | “AOD-9604 + HGH Frag 176-191” | Related identities presented together, not a standardized blend | Seller declaration only |
| AOD-9604-alone claims | “AOD-9604” | Should refer to Tyr-hGH 177-191 | An entry with frequent visibility in the research-peptide ecosystem. Visibility is not endorsement, and marketed material is not assumed safe, sterile, authentic, or suitable for humans. Fonte da definição: Scope and selection methodology · Glossário identity and reports vary |
| Native-fragment claims | “HGH Frag 176-191” | Often conflated with AOD-9604 | Exact identity not independently verified |
These are often marketed as a "stack" for fat loss but are chemically distinct variants of the same GH region, not complementary peptides.
Native HGH fragment 176-191 and AOD-9604, described here as Tyr-hGH 177-191, each span sixteen abstract positions but differ at the N terminus. The modified identity boundary prevents AOD-9604 human findings from being assigned to the native fragment. Market names are often conflated, but evidence is not transferable.
Market-claim detail
Observed listings included variable declarations and claims in the 2–5 mg range for either name. These seller declarations add no identity or clinical evidence and are not guidance.
Component evidence
| Exact material | Human evidence | Combination claim | Compatibility relevance |
|---|---|---|---|
| AOD-9604 (Tyr-hGH 177-191) | Six phase 1/2 studies were reported; the 24-week phase 2b study enrolled 536 participants and failed its primary endpoint. Development was discontinued in 2007. | No meaningful standardized combination identified | The identities are related variants, not compatibility evidence |
| Native HGH Fragment 176-191 | No published human trial identified; AOD-9604 data are often reassigned incorrectly | No meaningful standardized combination identified | AOD-9604 evidence cannot establish the native fragment's properties |
AOD-9604 is distinguished by an N-terminal tyrosine that improves stability. The grey-market HGH Frag 176-191 lacks this modification.
Combination-specific studies
No study has tested AOD-9604 + HGH Frag 176-191 as a combination because they are variant forms of the same peptide, not complementary agents.
Safety and interaction uncertainties
AOD-9604 well-tolerated in Phase I/II; no IGF-1 elevation; no glucose disruption
Unmodified HGH Frag 176-191 has no human safety data
GRAS notice (GRN 000792) for food ingredient use — not a drug approval
The World Anti-Doping Agency; its Prohibited List classifies many peptides as prohibited substances in sport. Fonte da definição: WADA and sport regulation brief · Glossário: both prohibited as GH fragments (WADA Prohibited List class S2 (peptide hormones, growth factors, related substances and mimetics): prohibited at all times, with subsections of materially different scope. Fonte da definição: WADA and sport regulation brief · Glossário class)
Regulatory and product-quality notes
Neither is FDA-approved for any indication
AOD-9604 was an A clinical-stage candidate with scientific or public relevance. Investigation is not approval, and a studied exposure is not a recommendation. Fonte da definição: Scope and selection methodology · Glossário drug; development terminated 2007
Mislabeling between AOD-9604 and HGH Frag 176-191 is widespread
FDA enforcement actions against compounders marketing unapproved peptides
Evidence gaps
No human trial data for HGH Frag 176-191 specifically
AOD-9604's published trial data never appeared in PubMed-indexed journals
No established or recommended human dose for either exact material
Widespread vendor confusion between the two variants
The market-claim detail is kept in a subordinate disclosure because seller amounts add no identity evidence. See identity methodology, WADA and sport, and the blend index.
Sources
Clinical Peptide. AOD-9604 vs HGH Fragment 176-191. https://clinicalpeptide.org/compare/aod-9604-vs-hgh-frag-176-191/ accessed 2026-08-06.
PeptideBase. AOD-9604 Research Guide. https://peptidebase.io/peptides/aod-9604 accessed 2026-08-06.
HealthRX. HGH Frag 176-191 Evidence. https://healthrx.com/peptides-specialty/hgh-frag-176-191 accessed 2026-08-06.
Useful Vitamins. AOD-9604 Explained. https://usefulvitamins.com/aod-9604-explained/ accessed 2026-08-06.
Heffernan M, et al. Endocrinology. 2001;142(11):4723-4730. PMID 11713213.

