HGH Fragment (176-191)

• Form: Lyophilized peptide
• Net per vial: 10 mg (filled to approximately 104% of label)
• Purity: ≥99% (HPLC-verified)
• Identity: MS-verified (per COA)
• Storage: 2–8 °C, protect from light
• Formula / M.W.: C₇₈H₁₂₅N₂₃O₂₃S₂ / 1817.12 Da
• CAS: 221231-10-3

HGH Fragment 176-191 was developed in the late 1990s by Frank Ng and colleagues at Monash University, Australia, as part of a structure-activity program designed to isolate the lipolytic domain of human growth hormone from its broader endocrine activity. The compound was subsequently licensed to Metabolic Pharmaceuticals — later Calzada — and advanced through Phase 2 clinical trials in obesity in the early 2000s under the development code AOD-9604.

What distinguishes the fragment in research is its mechanistic specificity. Full-length hGH binds the GH receptor and triggers the complete cascade — IGF-1 elevation, growth signaling, glucose handling, and lipolysis. By using only the C-terminal 16 residues, HGH Fragment 176-191 retains lipolytic activity without engaging the GH receptor in the IGF-1-stimulating mode. That decoupling gives Canadian research groups a clean tool for studying adipose-specific hGH actions in isolation from the systemic GH/IGF-1 axis effects that confound full-hGH study designs.

• Lipolysis & Fatty Acid Mobilization — Published preclinical studies have characterized HGH Fragment 176-191's activation of hormone-sensitive lipase and stimulation of fatty acid release from adipose tissue, with effects observed in both subcutaneous and visceral adipocyte models.
• Anti-Lipogenic Activity — Animal studies have measured reductions in fatty acid synthesis alongside increased lipolysis, generating sustained interest in the fragment as a research tool for adipose-specific dual-mechanism investigation.
• Body Composition Models — Rodent obesity models have reported reductions in fat mass without proportional changes in lean mass following HGH Fragment 176-191 administration, with mechanistic work attributing the selectivity to the absence of GH-receptor-mediated growth signaling.
• Decoupled Metabolic Research — Unlike full hGH, the fragment does not substantially elevate IGF-1 or alter glucose homeostasis in published animal models, making it a useful tool for research designs requiring lipolysis activity without confounding GH/IGF-1 axis effects.
• Cartilage & Joint Research — A subset of preclinical work has examined HGH Fragment 176-191 in osteoarthritis and cartilage degradation models, characterizing effects on chondrocyte signaling that are mechanistically distinct from its primary lipolytic profile.

Researchers working with HGH Fragment 176-191 often investigate it alongside:

• Tesamorelin — GHRH analog that stimulates pituitary GH release and triggers the full GH/IGF-1 cascade; the standard mechanistic contrast for research designs comparing isolated lipolytic activity against full-axis activation.
• Retatrutide — Triple GLP-1/GIP/glucagon agonist with documented adiposity-research data; provides a receptor-level metabolic-pathway contrast to HGH Fragment 176-191's adipocyte-direct lipolytic mechanism.
• MOTS-c — Mitochondria-derived peptide that activates AMPK; complements HGH Fragment 176-191's lipolytic profile with a cellular-energetics angle on metabolic research.

Where can researchers buy HGH Fragment 176-191 in Canada with verified purity?

Our HGH Fragment 176-191 ships to Canadian research labs and independent investigators with a batch-specific certificate of analysis confirming ≥99% HPLC purity and mass-spec identity verification. Vials are filled to approximately 104% of the labeled 10 mg as a quality margin for residual losses during reconstitution work, and ship from within Canada to avoid border-related cold-chain interruptions.

How is HGH Fragment 176-191 different from Tesamorelin or full hGH?

The three operate at different points in the GH axis. Full hGH binds the GH receptor and triggers the complete cascade — IGF-1 production, growth signaling, glucose modulation, and lipolysis. Tesamorelin is a GHRH analog that stimulates pituitary GH release, indirectly producing the full hGH cascade. HGH Fragment 176-191 isolates only the C-terminal lipolytic region of hGH, retaining fat-mobilization activity without engaging the GH receptor in the IGF-1-stimulating mode. Research designs select among the three based on whether full-axis activation, indirect GH stimulation, or isolated lipolysis is the relevant mechanism.

Is HGH Fragment 176-191 the same as AOD-9604?

The two are closely related and frequently treated as synonymous in research peptide markets. HGH Fragment 176-191 refers to the synthetic 16-amino-acid sequence corresponding to residues 176-191 of human growth hormone. AOD-9604 is the same fragment as developed by Metabolic Pharmaceuticals and tested in Phase 2 clinical trials in obesity. Most research suppliers use the names interchangeably, and the published preclinical literature largely treats them as equivalent compounds.

Is HGH Fragment 176-191 naturally occurring?

Partially. The 16-amino-acid sequence corresponds exactly to residues 176-191 of native human growth hormone, an endogenous peptide hormone produced by the anterior pituitary. The fragment itself does not occur freely in nature — it is a synthetic peptide isolated from the parent hGH sequence to study the lipolytic activity of that specific region. The synthetic peptide sold for research is sequence-identical to the corresponding region of native hGH.