HGH Fragment 176-191
Also known as: AOD9604, hGH 176-191, Human Growth Hormone Fragment 176-191
Growth hormone (GH) C-terminal peptide fragment
What it is
HGH Fragment 176-191 corresponds to amino acids 176–191 of the human growth hormone (hGH) molecule. In vivo animal studies (normal rats) demonstrated that this C-terminal fragment produces a short-lived rise in blood glucose and a more sustained rise in plasma insulin; the fragment also reduced insulin sensitivity in intravenous insulin tolerance tests. These effects required both the minimum informational sequence and correct physical configuration of the peptide. In vitro / in silico research has explored the peptide's binding affinity to breast cancer protein targets, suggesting it may enhance doxorubicin binding to those receptors when co-loaded in chitosan nanoparticles. It is also classified in the clinical/performance-enhancement literature as a GH fragment (alias AOD9604) marketed among unregulated performance-enhancing peptides purported to modulate the GH-IGF-1 axis. No human pharmacodynamic mechanism data are present in the reviewed abstracts.
Class: Growth hormone (GH) C-terminal peptide fragment
What it's studied for
- Glycemic / insulinotropic effects (in vivo animal model) Animal studies only
- hGH 176-191 (5 nmol/kg body weight, single dose) produced a short-lived rise in blood glucose and a sustained rise in plasma insulin in normal rats, and reduced insulin sensitivity in IV insulin tolerance tests. PMID 645904 Ng FM, Bornstein J. Hyperglycemic action of synthetic C-terminal fragments of human growth hormone. Am J Physiol. 1978.
- Enhancement of doxorubicin anticancer efficacy via chitosan nanoparticle co-loading (in vitro / in silico) In vitro only
- Molecular docking simulations showed hGH 176-191 enhances doxorubicin binding to multiple breast cancer protein targets. Dual-loaded chitosan nanoparticles demonstrated greater anti-proliferative activity against MCF-7 breast cancer cells than doxorubicin-loaded chitosan alone. PMID 35783198 Habibullah MM et al. Human Growth Hormone Fragment 176-191 Peptide Enhances the Toxicity of Doxorubicin-Loaded Chitosan Nanoparticles Against MCF-7 Breast Cancer Cells. Drug Des Devel Ther. 2022.
- Performance enhancement / body recomposition (off-label, self-administration) Human observational
- AOD9604 (hGH 176-191) is listed among unregulated performance-enhancing peptides encountered in clinical practice and online self-administration protocols targeting the GH-IGF-1 axis. The review stratifies it into evidence tiers and highlights the absence of regulatory approval for physique- or performance-related indi PMID 42395176 Dominikowski A et al. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis. Front Endocrinol. 2026.
Community-reported dosing
| Route | Dose | Frequency / Duration | Population / context | Source tier |
|---|---|---|---|---|
| Not explicitly stated in abstract (in vivo rat study) | 5 nmol/kg body weight (single dose) | Single dose | animal | Research PMID 645904 |
| subcutaneous injection | 250 mcg | once daily (morning, fasted) | biohackers and recreational users targeting fat loss | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 500 mcg | once daily (morning, fasted) | biohackers and recreational users targeting fat loss | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 1000 mcg | once daily (morning, fasted) | experienced biohackers and higher-end users pursuing aggressive fat loss | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 500 mcg | twice daily (morning fasted + 30 min pre-workout or mid-afternoon fasted) | fitness-focused biohackers stacking fasted training with peptide timing | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 250 mcg | twice daily (morning fasted + 30 min pre-workout) | beginners or lighter users new to Frag 176-191 who start conservative | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 500 mcg | once daily, pre-workout (fasted, 30 min before training) | athletes and gym-focused users pairing with fasted cardio or resistance training | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 500 mcg | once daily (morning fasted) | biohackers stacking Frag 176-191 with CJC-1295/Ipamorelin for combined GH secretagogue + targeted fat loss | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 500 mcg | once daily (morning fasted) | biohackers stacking Frag 176-191 with AOD-9604 or Tesamorelin for synergistic lipolysis | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 500 mcg | once daily (morning fasted) | long-term biohackers concerned about tachyphylaxis or receptor desensitization | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
| subcutaneous injection | 250 mcg | once daily (morning fasted) | female users or lower-bodyweight users who dose conservatively | [S] Claude Sonnet 4.6 — synthesized from aggregate training data |
Tier key: Research = PMID-cited study · [C] = scraped community source · [S] = model-synthesized from aggregate community reports (softer evidence). How we source.
Safety signals
- Reduced insulin sensitivity observed in normal rats following a single dose of hGH 176-191 (5 nmol/kg); also associated with blood glucose elevation and sustained plasma insulin rise. PMID 645904
- HGH 176-191 (AOD9604) is grouped with performance-enhancing peptides for which adverse effects across the class include prolactin and cortisol elevations, appetite changes, dysglycaemia, fluid retention, myalgia/arthralgia, and injection-site reactions. Specific safety signals attributable solely to HGH 176-191 are not individually delineated. PMID 42395176
- Biologically plausible but unproven mitogenic concerns are noted for GH-axis peptides as a class in the context of unregulated self-administration. PMID 42395176
Contraindications
- No specific contraindications for HGH Fragment 176-191 are stated in the reviewed abstracts. The broader class of unregulated GH-axis peptides is described as lacking regulatory approval for performance- or physique-related indications. PMID 42395176
Frequently asked
What is HGH Fragment 176-191 and what is it used for?
HGH Fragment 176-191 (also called AOD9604) is a synthetic peptide corresponding to amino acids 176–191 of human growth hormone. In animal research, it was shown to produce short-lived blood glucose elevation and sustained plasma insulin increases in normal rats. In vitro/in silico research has examined its potential to enhance doxorubicin's anticancer activity when co-loaded into chitosan nanoparticles against MCF-7 breast cancer cells. It is also encountered in the context of off-label self-administration for performance or body recomposition purposes, though it lacks regulatory approval for any such indications.
What dose of HGH Fragment 176-191 should I take?
I'm not a medical professional and can't recommend a protocol for you specifically. What research has shown: The only dose reported in the reviewed abstracts is 5 nmol/kg body weight as a single dose in normal rats. No human dosing data are available in the reviewed literature.
Is HGH Fragment 176-191 approved by the FDA or other regulatory agencies?
The reviewed abstracts do not explicitly state the current FDA, Health Canada, or WADA regulatory status of HGH Fragment 176-191. One review notes the absence of regulatory approval for physique- or performance-related indications for this class of GH-axis peptides. Please consult official regulatory agency websites or a licensed healthcare provider for current status.
Can I stack HGH Fragment 176-191 with other peptides like GHRP-6 or CJC-1295?
I can't recommend combining compounds — that's a prescribing decision. Here's what has been studied individually: HGH Fragment 176-191 has been studied only in animal models and in vitro. The reviewed literature flags stacking practices as a source of uncertainty and risk in unregulated settings.
Does HGH Fragment 176-191 cause any side effects?
In animal studies, hGH 176-191 was associated with blood glucose elevation, sustained plasma insulin rises, and reduced insulin sensitivity at a single dose of 5 nmol/kg. The broader class of GH-axis peptides — which includes AOD9604 — has been associated with adverse effects including endocrine/metabolic disturbances (prolactin and cortisol elevations, dysglycaemia), fluid retention, myalgia/arthralgia, and injection-site reactions in self-administration contexts. Specific human safety data for HGH Fragment 176-191 alone are not available in the reviewed abstracts.
Where can I buy HGH Fragment 176-191?
I don't recommend vendors or sources. Please consult a licensed provider.
Does HGH Fragment 176-191 burn fat or improve body composition?
I don't have reliable study data on that specific question. I won't guess — please consult a licensed provider or peer-reviewed literature directly. The reviewed abstracts do not include human studies on fat loss or body recomposition effects of this peptide.
Is HGH Fragment 176-191 safe to inject at home?
I'm not a medical professional and can't recommend a protocol for you specifically. What research has shown: No human clinical data on self-injection safety for HGH Fragment 176-191 appear in the reviewed abstracts. The peptide is marketed as an unregulated research compound; product composition, dose accuracy, and purity in unregulated supply chains are uncertain. Reduced insulin sensitivity was observed in animal studies. Please consult a licensed healthcare provider before using any unregulated injectable compound.
Has HGH Fragment 176-191 been tested in humans?
The reviewed abstracts do not include any human clinical trials or pharmacokinetic studies for HGH Fragment 176-191. The only in vivo data come from animal (rat) studies, and additional research is limited to in vitro and in silico experiments. It is referenced in a clinical review as an unregulated compound encountered in self-administration contexts.
Can HGH Fragment 176-191 treat or prevent cancer?
I can't suggest treatments for medical conditions. Please speak with a licensed healthcare provider. The reviewed abstracts describe in vitro and in silico research on HGH Fragment 176-191 as a potential adjunct to doxorubicin in a breast cancer cell line model only — this is early-stage laboratory research and does not establish clinical efficacy or safety in humans.
References
- [1] PMID 645904 — hGH 176-191 (5 nmol/kg body weight, single dose) produced a short-lived rise in blood glucose and a sustained rise in plasma insulin in normal rats, and reduced
- [2] PMID 35783198 — Molecular docking simulations showed hGH 176-191 enhances doxorubicin binding to multiple breast cancer protein targets. Dual-loaded chitosan nanoparticles demo
- [3] PMID 42395176 — AOD9604 (hGH 176-191) is listed among unregulated performance-enhancing peptides encountered in clinical practice and online self-administration protocols targe