HGH Fragment 176-191
HGH Frag / Fragment 176-191
HGH Fragment 176-191 is a synthetic peptide corresponding to amino acids 176-191 of the C-terminal region of human growth hormone, specifically isolated for its lipolytic (fat-burning) properties without the growth-promoting or diabetogenic effects of full-length HGH. It was identified through research at Monash University demonstrating that this specific fragment retains the fat-metabolizing activity of growth hormone while lacking IGF-1 stimulating capacity. Its primary research applications focus on targeted fat loss, obesity treatment, and metabolic regulation without the broader hormonal effects of full GH administration.
Mechanism of Action
The lipolytic fragment of human growth hormone encompassing amino acids 176-191. Promotes fat metabolism through beta-3 adrenergic receptor pathways.
Research Protocols
For research purposes only. Not medical advice.
Research protocols use 250-500mcg twice daily, subcutaneous. Administer on empty stomach.
Research Notes
Clinical Research Status
HGH Fragment 176-191 (also designated AOD-9604 in its modified form) has undergone Phase II clinical trials for obesity conducted by Metabolic Pharmaceuticals Limited in Australia. The modified version AOD-9604 received FDA GRAS (Generally Recognized as Safe) status in 2014 for use in food products, though it is not approved as a pharmaceutical. Research interest continues in the peptide community for body composition applications, though formal clinical development has largely stalled since initial trial results showed modest efficacy in weight loss endpoints.
Key Published Findings
Original research by Ng and Borstein at Monash University demonstrated that Fragment 176-191 stimulates lipolysis in adipose tissue at concentrations 12.5 times more potent than full-length HGH on a molar basis. Clinical trials with the AOD-9604 form showed statistically significant weight loss versus placebo over 12 weeks, with preferential reduction of abdominal fat. Importantly, studies confirmed that the fragment does not induce insulin resistance, does not elevate IGF-1 levels, and does not promote long bone growth, effectively isolating the lipolytic mechanism from other GH effects.
Safety Profile
Clinical trial data demonstrated excellent tolerability with no serious adverse events attributed to the peptide at studied doses. The compound does not affect blood glucose or insulin sensitivity, differentiating it significantly from exogenous growth hormone administration. As it does not stimulate IGF-1, theoretical cancer risk concerns associated with elevated growth factors do not apply to this fragment.
Drug Interactions & Contraindications
No significant drug interactions have been identified in clinical studies, consistent with its narrow mechanism of action on adipose tissue. Concurrent use with exogenous growth hormone may be redundant, as both compounds act on the same lipolytic pathway. Caution is theoretically warranted in individuals with extremely low body fat, and the compound should not be used by individuals with active eating disorders.
Comparison to Related Compounds
Unlike full-length HGH which stimulates growth, IGF-1 production, and can cause insulin resistance, Fragment 176-191 specifically and exclusively targets fat metabolism. AOD-9604 is a modified version with a tyrosine residue added to position 176 for improved stability, and the two are often conflated in community discussions. CJC-1295 and GHRP combinations stimulate endogenous GH release (which includes lipolytic effects) but also produce all other GH-mediated effects including potential insulin resistance and IGF-1 elevation.
Community Observations
Users typically administer Fragment 176-191 at 250-500mcg subcutaneously 1-2 times daily, ideally on an empty stomach and separated from food by 30+ minutes to avoid insulin-mediated interference with lipolysis. Reports suggest best results when combined with fasted cardio and moderate caloric deficit, with effects becoming noticeable over 4-8 weeks of consistent use. The community generally considers it a mild but well-tolerated fat loss agent, noting that dramatic results require simultaneous dietary discipline and that it works synergistically with other lipolytic compounds.
Half-Life
~15-20 minutes
Reconstitution
Bacteriostatic water (BAC)
Storage
Lyophilized
Refrigerate 2-8C up to 12 months.
Reconstituted
Refrigerate 2-8C. Use within 21 days.
US Legal Status
Also Known As
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