Fragment 176-191
Preclinical ResearchGrowth Hormone Releasing Peptide Fragment 176-191
The fat-regulating tail fragment of human growth hormone. Studied for lipolysis (fat breakdown) without the growth-promoting effects of full GH.
Dose
200-500 mcg
Route
SubQ injection
Cycle
8-12 weeks
Storage
Refrigerated (2-8°C / 36-46°F) away from light.
What is Fragment 176-191?
Fragment 176-191 is a synthetic peptide representing the C-terminal fragment of human growth hormone (hGH). It comprises amino acid residues 176-191 of the full hGH sequence. Research indicates that this fragment is responsible for the fat-reducing effects of hGH without inducing the growth-promoting effects or impacting insulin sensitivity and glucose levels. It is hypothesized to selectively bind to receptors in adipose tissue, leading to increased lipolysis (fat breakdown) and inhibition of lipogenesis (fat formation). Its mechanism of action is often compared to AOD-9604 due to their similar C-terminal hGH origins.
Key Benefits
- Fat burning
- Lipolysis stimulation
- No effect on blood sugar or IGF-1
- Body composition improvement
Mechanism of Action
- Binds fat cells
- Stimulates fat breakdown
- Inhibits fat formation
- Similar mechanism to AOD-9604
Best For
- Fat loss research
- Body composition
Body Systems

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Molecular Information
Molecular weight
1817.1 g/mol
Length
16 amino acids
Type
Peptide
Amino acid sequence
YLRIVQCRSVEGSCGF
Tyrosine-Leucine-Arginine-Isoleucine-Valine-Glutamine-Cysteine-Arginine-Serine-Valine-Glutamic acid-Glycine-Serine-Cysteine-Glycine-Phenylalanine
Pharmacokinetics
Half-life
0.5 h
Time to clear
Approximately 1.5-2.5 hours
Based on studies on similar GH fragments and general peptide pharmacokinetics.
Research Indications
Lipolysis Stimulation
Fragment 176-191 is studied for its ability to stimulate the breakdown of fat cells (lipolysis), leading to the release of fatty acids for energy.
Inhibition of Lipogenesis
Research suggests it may also inhibit the formation of new fat cells and prevent the conversion of non-fatty food materials into body fat.
Research Protocols
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| General Fat Loss & Body Composition Improvement | 200-250 mcg | 2 times daily | Subcutaneous injection |
| Accelerated Fat Loss (More Intensive Protocol) | 300-500 mcg | 1-2 times daily | Subcutaneous injection |
| Maintenance or Mild Fat Loss Support | 200 mcg | 1 time daily | Subcutaneous injection |
| Pre-Cardio Fasted State Lipolysis | 200-250 mcg | Once daily, 30-60 minutes before fasted cardio | Subcutaneous injection |
Administration in a fasted state is commonly discussed to optimize its potential effects on fat metabolism, as food intake (especially carbohydrates) can cause an insulin response that might blunt its lipolytic action.
Peptide Interactions
- Use Caution
Insulin
While Fragment 176-191 does not significantly affect blood glucose, insulin promotes fat storage. Administering Fragment 176-191 in a fasted state and separate from insulin administration is commonly discussed to avoid counteracting effects.
- Compatible
Other GH-Releasing Peptides (e.g., GHRP-2, GHRP-6, Ipamorelin, CJC-1295)
Fragment 176-191 has a distinct mechanism of action, directly targeting fat cells, whereas GHRPs and GHRHs stimulate endogenous GH release. They are often discussed for use in combination without direct interference, potentially offering complementary effects.
- Monitor Combination
Oral Hypoglycemic Agents (for diabetes)
Although Fragment 176-191 is not known to impact blood sugar, individuals on diabetes medication should monitor their blood glucose closely when introducing new compounds.
- Use Caution
Corticosteroids
Corticosteroids can promote fat storage and oppose lipolysis. While not a direct interaction, simultaneous use might reduce the efficacy of Fragment 176-191's fat-reducing effects.
How to Reconstitute
- 1Gather materials: lyophilized peptide vial, bacteriostatic water, sterile syringe, and alcohol wipes.
- 2Remove the plastic cap from the peptide vial and wipe the rubber stopper with an alcohol wipe.
- 3Wipe the top of the bacteriostatic water vial with an alcohol wipe.
- 4Draw the desired amount of bacteriostatic water (e.g., 1-2 mL) into the syringe.
- 5Slowly inject the bacteriostatic water into the peptide vial, aiming the stream against the side of the vial, not directly onto the peptide powder.
- 6Do not shake the vial. Gently swirl the vial to aid dissolution. If undissolved particles remain, allow it to sit in the refrigerator for a few minutes and swirl again.
- 7Once fully dissolved, store the reconstituted solution in the refrigerator.
Always reconstitute with bacteriostatic water for injection. Use a sterile technique.
What to Expect
- Weeks 1-2: Initial observations may include subtle changes in energy levels or a slight decrease in appetite. No significant body composition changes are typically seen yet.
- Weeks 3-6: Users may begin to notice slight reductions in body fat, particularly around the abdominal area, assuming adherence to a calorie-controlled diet and exercise.
- Weeks 7-12: More noticeable improvements in body composition, including further fat loss and potentially increased lean mass definition, may become apparent. Optimal results often require consistent use alongside appropriate lifestyle choices.
- Post-cycle: Benefits are generally maintained if a healthy diet and exercise regimen continue. Rebound fat gain is possible if lifestyle habits revert.
Side Effects & Safety
| Effect | Frequency | Severity |
|---|---|---|
| Injection site irritation | Common | Mild |
| Headache | Uncommon | Mild |
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Open CalculatorPeptides discussed here are for research purposes only. Nothing on this page is medical advice. Always consult a qualified professional before making health decisions.