A C-terminal fragment of human growth hormone specifically associated with lipolysis and fat burning.
HGH Fragment 176-191 is a 16-amino acid peptide corresponding to the C-terminal portion of human growth hormone (amino acids 176-191). It is closely related to AOD-9604 (which is Fragment 177-191 with an additional N-terminal tyrosine). This fragment is believed to contain the portion of hGH responsible for lipolytic (fat-burning) activity.
The rationale for isolating this fragment is that full HGH has multiple biological effects — growth promotion, glucose metabolism alteration, IGF-1 stimulation, and lipolysis. HGH Fragment 176-191 is designed to preserve only the lipolytic effects, without the anabolic growth promotion, glucose effects, or IGF-1 stimulation of full HGH.
Evidence for HGH Fragment 176-191 is primarily from in vitro cell studies and animal models. Human clinical trial data is minimal. It has not been developed into a pharmaceutical product like AOD-9604 was (which also failed Phase 3). The evidence base for this specific fragment in humans is very limited.
Cell culture and rodent studies suggest HGH Fragment 176-191 stimulates lipolysis in fat cells and inhibits new fat cell formation. In obese animal models, body fat reduction was observed. However, these findings have not translated to approved clinical applications.
The lack of human clinical trial data and no FDA-approved formulations mean this peptide exists primarily in research and gray-market compounding contexts. Comparison to GLP-1 agonists for fat loss is dramatically unfavorable on evidence.
📚 Key Reference: PMID: 11146367 (hGH fragment lipolysis research)
Limited human safety data. Animal studies suggest good tolerability. Without robust human trials, unknown risks exist. Quality concerns with unregulated sources are significant. Consult your provider.
NOT FDA-approved. Research use only. No pharmaceutical-grade human formulations. Significant concern about quality of gray-market sources.