Growth ⏱ Half-life: Short — approximately 30 minutes. Multiple daily doses used in research protocols. Experimental

Fragment 176-191

HGH Fragment 176-191

Updated March 15, 2026

Evidence at a Glance

Regulatory statusExperimental
No human trials of the fragment itself; the closely related analog AOD-9604 reached Phase 2b for obesity but failed to beat placebo and was abandoned in 2007
Human evidenceNone
Animal evidenceLimited

This C-terminal growth-hormone fragment has essentially no human research of its own, and its studied analog AOD-9604 failed to produce significant fat loss in a 500-plus-person Phase 2b trial.

What the research does not support

  • It is not approved for weight loss anywhere and the fragment itself has essentially no human trials.
  • Its studied analog AOD-9604 failed to beat placebo in a Phase 2b obesity trial of over 500 people and was dropped as a drug candidate.
  • It does not raise IGF-1 or build muscle the way full growth hormone does.
  • Marketed "targeted" or "spot" fat-burning claims are unproven in humans.
Half-Life
Short — approximately 30 minutes. Multiple daily doses used in research protocols.
Mol. Weight
1817.12 g/mol

What is Fragment 176-191?

HGH Fragment 176-191 is the naturally occurring C-terminal portion of human growth hormone that contains the fat-metabolic signaling region. It represents the minimal active sequence for GH-mediated lipolysis without the growth-promoting or diabetogenic effects of the full hormone.

Research Applications

Fat metabolism, lipolysis signaling, body composition research without IGF-1 elevation, and comparative studies with AOD-9604.

Dosage Information (Research Use)

Research protocols: 250-500 mcg subcutaneously, 1-2 times daily, typically on an empty stomach. Research use only.

Reconstitution & Handling

Standard BAC water reconstitution.

Half-Life & Pharmacokinetics

Short — approximately 30 minutes. Multiple daily doses used in research protocols.

Reported Observations in Literature

Generally well-tolerated. Injection site irritation reported. No significant effects on glucose or IGF-1.

Key Research References

  • Wu Z, et al. “The C-terminal fragment 177-191 of growth hormone has lipolytic effects.” Biochem Biophys Res Commun. 1993

How Fragment 176-191 Works

Fragment 176-191 is the unmodified C-terminal segment of human growth hormone responsible for the lipolytic (fat-burning) activity of the full hormone. Unlike AOD-9604 (which adds a tyrosine residue), this is the native sequence fragment.

Research Findings

Studied alongside AOD-9604 in fat metabolism research. Does not elevate IGF-1 or affect blood glucose in published data.

Dosage & Administration

Research protocols: 250-500 mcg subcutaneously, 1-2 times daily, typically on an empty stomach. Research use only.

Safety & Side Effects

Generally well-tolerated. Injection site irritation reported. No significant effects on glucose or IGF-1.

Important: All safety information is derived from published research, primarily animal studies. No controlled human clinical trial data exists unless explicitly noted. This compound is sold for research purposes only.

Quick Facts

Sequence Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe
Molecular Weight 1817.12 g/mol
Half-Life Short — approximately 30 minutes. Multiple daily doses used in research protocols.
Available Sizes 2mg, 5mg
Storage Lyophilized: -20°C. Reconstituted: 2-8°C.

Key Research References

  • Wu Z, et al. "The C-terminal fragment 177-191 of growth hormone has lipolytic effects." Biochem Biophys Res Commun. 1993

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