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What Is HGH Fragment 176-191? Benefits, Research & Safety
A fragment of human growth hormone corresponding to amino acids 176-191, researched specifically for its fat-metabolising properties.
Also known as:
HGH Frag
Fragment 176-191
Lipolytic Fragment
Educational Content Only: This page provides research-based information for educational purposes. HGH Fragment 176-191 is not an approved medicine. This is not medical advice. Always consult a qualified healthcare professional.
Quick Facts
Category
Fat Loss & Metabolic
Half-Life
Short; approximately 30 minutes to a few hours
UK Status
Not licensed for human use. Research compound only.
EU Status
Not approved for human therapeutic use.
Overview
HGH Fragment 176-191 is a synthetic peptide corresponding to the C-terminal portion of human growth hormone (hGH), specifically amino acids 176 through 191. This region of the growth hormone molecule has been identified as containing the lipolytic (fat-burning) activity of the full hormone.
The development of this fragment was based on research demonstrating that the fat-metabolising effects of growth hormone could be separated from its growth-promoting effects. By isolating this specific fragment, researchers aimed to harness the fat-loss benefits without the concerns associated with full growth hormone administration, such as effects on blood glucose, IGF-1 elevation, and tissue growth.
Research has shown that HGH Fragment 176-191 can stimulate lipolysis (breakdown of fat) and inhibit lipogenesis (formation of new fat) without significantly affecting blood glucose levels or promoting growth. This makes it of interest for body composition research.
HGH Fragment 176-191 is closely related to AOD-9604, which is essentially the same fragment with an additional tyrosine residue at the N-terminus. Both peptides share similar mechanisms and research applications.
This peptide remains a research compound and is not approved for human therapeutic use.
Discovery & History
The development of HGH Fragment 176-191 arose from research into the structure-function relationships of human growth hormone. Scientists at Monash University in Australia, led by Professor Frank Ng, investigated which regions of the hGH molecule were responsible for its various biological activities.
Research in the 1990s identified the C-terminal region (amino acids 176-191) as being particularly important for growth hormone's lipolytic activity. Studies demonstrated that this fragment could reduce body fat in obese mice without promoting growth or affecting IGF-1 levels.
This work led to the development of both HGH Fragment 176-191 and the related compound AOD-9604 (which has an additional N-terminal tyrosine). The goal was to create compounds that could provide the fat-loss benefits of growth hormone without its broader hormonal effects.
While HGH Fragment 176-191 has been extensively studied in preclinical models, human clinical data remains limited. AOD-9604, the closely related compound, has progressed further in clinical development.
Mechanism of Action
HGH Fragment 176-191 works through mechanisms distinct from full growth hormone:
**Lipolysis Stimulation**
The fragment stimulates the breakdown of triglycerides stored in adipose tissue, releasing fatty acids into the bloodstream for use as energy. This lipolytic effect occurs through activation of hormone-sensitive lipase in fat cells.
**Lipogenesis Inhibition**
Research suggests the fragment inhibits the formation of new fat from dietary carbohydrates and other substrates, potentially reducing fat storage.
**Selective Fat Action**
Unlike full growth hormone, the fragment appears to act primarily on adipose tissue without significant effects on muscle, bone, or other tissues that would respond to complete hGH.
**IGF-1 Independence**
HGH Fragment 176-191 does not appear to stimulate IGF-1 production, distinguishing its effects from those of full growth hormone and potentially reducing associated risks.
**Glucose Neutrality**
Studies suggest the fragment does not significantly affect blood glucose or insulin sensitivity, unlike full growth hormone which can impair glucose metabolism.
[Molecular Structure Diagram Placeholder]
Researched Benefits
Based on preclinical and clinical research findings:
- 1Stimulation of fat breakdown without affecting muscle tissue
- 2Inhibition of new fat formation
- 3No significant effect on blood glucose in studies
- 4No stimulation of IGF-1 production
- 5No growth-promoting effects observed
- 6Potential for targeted fat reduction
Theoretical Dosing & Protocols
⚠️ Educational Only: The following information is derived from research literature and is not a prescription or recommendation. No standardised human dosing exists. Always consult a qualified healthcare professional.
| Theoretical Dosage | 250-500 mcg per administration (based on research protocols) |
| Frequency | 1-2 times daily, typically before cardio exercise |
| Duration | Variable in research settings; typically weeks to months |
| Notes | These are theoretical protocols derived from research literature. HGH Fragment 176-191 is not approved for human use. Any consideration of use should involve consultation with a qualified healthcare professional. |
Administration Routes
Routes studied in research settings (educational only):
- Subcutaneous injection
| Half-Life | Stability |
|---|---|
| Short; approximately 30 minutes to a few hours | Lyophilised powder should be stored frozen; reconstituted solution refrigerated |
Safety Profile & Known Risks
Commonly Reported Side Effects
- Injection site reactions
- Potential hypoglycaemia if used with insulin (theoretical)
- Headache (reported anecdotally)
Rare Risks & Concerns
- Long-term effects unknown in humans
- Potential for contamination in non-pharmaceutical grade products
- Effects on other metabolic parameters not fully characterised
Contraindications
- Pregnancy and breastfeeding
- Active malignancy
- Diabetes (use with caution)
- Children and adolescents
UK & EU Regulatory Context
🇬🇧 United Kingdom
Not licensed for human use. Research compound only.
🇪🇺 European Union
Not approved for human therapeutic use.
HGH Fragment 176-191 is not approved by any regulatory authority for human use. It is available only as a research chemical.
Clinical Studies Summary
Lipolytic Activity of a Human Growth Hormone Fragment
Preclinical research demonstrating the fat-metabolising activity of the 176-191 fragment of human growth hormone.
Various preclinical publicationsView on PubMed
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