AOD-9604 vs HGH Fragment 176-191
AOD-9604 (Modified GH-fragment peptide) and HGH Fragment 176-191 (Modified GH-fragment peptide) are documented as co-studied in the PeptiDex library. This page puts the two entries side by side on class, molecular weight, half-life, origin, mechanism and studied research areas — every value taken from the entry it belongs to.
Why these two are co-studied
Cross-referenced for research context — not a usage or combination recommendation.
At a glance
| Attribute | AOD-9604 | HGH Fragment 176-191 |
|---|---|---|
| Compound class | Modified GH-fragment peptide | Modified GH-fragment peptide |
| Research category | Metabolic & Mitochondrial | Metabolic & Mitochondrial |
| Length (amino acids) | 16 amino acids | 15 amino acids |
| Molecular weight | ~1815 g/mol | ~1817 g/mol |
| Half-life | ~20-40 minutes (reported) | ~15-20 minutes (reported) |
| Origin | AOD-9604 is a synthetic, stabilized analog of the C-terminal lipolytic region (residues 176-191) of human growth hormone, developed in the 1990s at Monash University. It adds an N-terminal tyrosine to the native fragment and retains the intramolecular disulfide bridge between the two cysteine residues. | HGH Fragment 176-191 is a synthetic peptide corresponding to the C-terminal region (residues 176-191) of human growth hormone. This portion of the GH molecule was identified as carrying the hormone's lipolytic activity. |
“Not documented” means the PeptiDex entry records no value for that field. Nothing on this page is estimated, and no figure is carried over from one compound to the other.
How AOD-9604 works
AOD-9604 corresponds to the C-terminal fragment of GH that carries the hormone's lipolytic (fat-metabolizing) activity while lacking the regions responsible for GH's growth-promoting and insulin-antagonizing effects. In preclinical models it has been reported to stimulate lipolysis and inhibit lipogenesis. It does not act as a full growth hormone and reportedly does not raise IGF-1 or affect blood glucose in the manner of intact GH.
How HGH Fragment 176-191 works
The fragment reproduces the C-terminal, lipolytic-associated region of GH while lacking the domains responsible for GH's growth-promoting and insulin-antagonizing actions. In preclinical models this region has been reported to stimulate fat breakdown (lipolysis) and reduce lipogenesis. It is not intact growth hormone and is not reported to reproduce GH's systemic growth effects.
Mechanistic descriptions reflect published research-literature understanding and are quoted from each compound's own entry. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
Where each one appears in the literature
The research contexts each entry documents. Listing a research area is not a claim of efficacy or a therapeutic indication, and the two lists are not scored against each other.
AOD-9604
HGH Fragment 176-191
What sets each apart
AOD-9604
Unlike full-length GH or GH secretagogues, AOD-9604 targets only the lipolytic C-terminal region; unlike the raw HGH Fragment 176-191, it carries an extra N-terminal tyrosine intended to improve stability.
HGH Fragment 176-191
This is the native GH C-terminal fragment; AOD-9604 is its modified, tyrosine-extended analog. Both isolate lipolytic activity away from full GH signaling.
Frequently asked questions
How does AOD-9604 differ from unmodified HGH Fragment 176-191?
AOD-9604 is a stabilized analog of HGH Fragment 176-191: it adds a tyrosine residue at the N-terminus of the native fragment. This modification was engineered in preclinical work to improve metabolic stability and lipolytic activity relative to the raw fragment. Both are studied for fat metabolism, but AOD-9604 is the more characterized, stabilized version.
What is AOD-9604 and what class of compound is it?
AOD-9604 is a synthetic 16-amino-acid peptide corresponding to the C-terminal region (residues 176-191) of human growth hormone, modified with an added N-terminal tyrosine and a disulfide bridge between its two cysteine residues. It is studied as a lipolytic (fat-metabolism) peptide that appears to isolate the fat-mobilizing activity of GH. It is a research peptide, not an approved therapeutic in most jurisdictions.
Does AOD-9604 raise IGF-1 or affect blood glucose in research models?
In preclinical models, AOD-9604 was reported to stimulate lipolysis and inhibit lipogenesis without the growth-promoting or diabetogenic effects associated with full-length growth hormone. Studies indicate it does not meaningfully elevate IGF-1 or disturb glucose handling in the models examined. These findings are from research settings and are not clinical guarantees.
How does HGH Fragment 176-191 differ from AOD-9604?
AOD-9604 is a stabilized analog of HGH Fragment 176-191: it adds an N-terminal tyrosine to the native fragment to improve stability and lipolytic activity. HGH Fragment 176-191 is the unmodified sequence. Both are studied for lipolysis, but the raw fragment is less characterized and has a very short duration.
What is HGH Fragment 176-191?
HGH Fragment 176-191 is a synthetic peptide corresponding to the C-terminal lipolytic region (residues 176-191) of human growth hormone (native sequence LRIVQCRSVEGSCGF). Research identified this segment as carrying the fat-mobilizing activity of GH, while the diabetogenic IGF-1-driving activity resides in a different region (roughly 1-43).
What does the short half-life imply for research design?
The fragment has a very short half-life (reported ~15-20 minutes), which is why research protocols often describe split dosing (e.g., morning and evening) to maintain exposure. Its rapid clearance is an important consideration when designing pharmacodynamic experiments around lipolysis.
Answers are the ones published on each compound's own PeptiDex entry. They are educational summaries of research-literature context and are not medical advice.