HGH Fragment 176-191 is a weight management research compound currently in stock directly from a verified Chinese manufacturer. Every batch is HPLC-verified and shipped with a Certificate of Analysis (COA). Sourcing is direct — no intermediaries. Minimum order value is $600 USD. International shipping available.
HGH Fragment 176-191 is a synthetic 16-amino acid peptide corresponding to the C-terminal region of human growth hormone (residues 176–191 of the 191 AA mature sequence). It was isolated following observations that the lipolytic activity of GH — stimulation of fat breakdown — could be attributed to the C-terminal region, while the growth-promoting and IGF-1-stimulating activity resided in the N-terminal domain. Structurally, the fragment retains a disulfide bridge between Cys-182 and Cys-189, which is essential for its biological activity. This selective structural correspondence is the foundation of research into the fragment as a tool for dissecting GH's metabolic actions from its anabolic effects.
Preclinical research in rodent models of obesity has examined HGH Fragment 176-191's effects on adipose tissue lipolysis and lipogenesis. Studies using radiolabelled glucose and fatty acids in fat cells demonstrate that the fragment stimulates fatty acid release from isolated adipocytes at a potency reportedly 12-fold greater than native GH in in vitro fat cell assays, without detectable IGF-1 elevation or glucose intolerance in short-duration protocols. The absence of GH receptor activation by the fragment — confirmed by receptor binding assays — distinguishes it mechanistically from intact GH in metabolic studies. Bone metabolism research represents a separate line of investigation, with in vitro osteoblast and osteoclast models used to characterise the fragment's effects on bone formation markers.
PeptidesFromChina.co supplies HGH Fragment 176-191 as lyophilized powder at ≥98% purity verified by HPLC and confirmed by mass spectrometry. Certificates of Analysis are available per batch. Wholesale quantities available on request. This compound is intended for laboratory research use only and is not for human administration.
| Chemical Class | GH C-terminal Fragment / Lipolytic Peptide |
|---|---|
| CAS Number | 66004-57-7 |
| Molecular Formula | C78H123N23O23S2 |
| Molecular Weight | 1817.12 Da |
| Sequence Length | 16 amino acids (residues 176–191 of hGH) |
| Disulfide Bond | Cys-182 — Cys-189 (essential for activity) |
| Synonyms | HGH Frag 176-191, AOD-9401, hGH fragment |
| Half-life (research) | ~20–30 min (rodent, s.c.) |
| Storage | -20°C lyophilized; 4°C reconstituted (up to 14 days) |
| Name | Strength | Pack Size | Purity | Availability | Price (USD) |
|---|---|---|---|---|---|
| HGH Fragment 176-191 | 2 mg | 10 vials | ≥98% | In Stock | $78.00 |
| HGH Fragment 176-191 | 5 mg | 10 vials | ≥98% | In Stock | $113.00 |
Testing method: HPLC / LC-MS. Every batch is tested before shipment. Purity ≥99% confirmed per batch.
Certificate of Analysis (COA) is included with every order. Documentation covers purity, molecular weight, and batch identification.
The primary research interest in HGH Fragment 176-191 is its capacity to stimulate lipolysis — fatty acid mobilisation from adipocytes — without activating the full GH receptor and its downstream anabolic and mitogenic pathways. In vitro experiments using primary rat adipocytes and 3T3-L1 differentiated fat cells show dose-dependent stimulation of glycerol and free fatty acid release. Crucially, the fragment does not compete with native GH at the GH receptor in binding competition assays, suggesting an alternative binding site or indirect mechanism. Comparative studies with intact GH use the fragment as a tool to isolate the lipolytic signalling pathway from IGF-1-dependent growth responses.
Native GH administration elevates both IGF-1 and causes transient insulin resistance in glucose tolerance models. HGH Fragment 176-191 studies in rodent obesity models report an absence of significant IGF-1 elevation and no glucose intolerance at doses producing measurable changes in adipose mass. This IGF-1 independence is mechanistically significant for research designs that need to examine fat-specific metabolic endpoints without confounding growth factor activity. Oral glucose tolerance tests (OGTT) in treated versus control obese rodents are a standard assay used to confirm this selectivity profile.
In vitro studies using osteoblast-like cell lines (MG-63, Saos-2) and primary calvarial osteoblasts have characterised HGH Fragment 176-191's effects on alkaline phosphatase activity, collagen synthesis, and osteocalcin expression — markers of osteoblast differentiation and matrix mineralisation. Osteoclast resorption assays using dentine slice systems have also been used to characterise whether the fragment modulates bone resorption independently of its lipolytic activity. These studies position the fragment as a tool for investigating GH-independent mechanisms of bone metabolism regulation.
Diet-induced obesity (DIO) and leptin-deficient (ob/ob) mouse models have been used to characterise HGH Fragment 176-191's effects on whole-body adiposity, measured by MRI body composition analysis and dual-energy X-ray absorptiometry (DEXA). Studies report preferential reductions in visceral adipose tissue versus subcutaneous depots in some rodent protocols, though the mechanistic basis for depot selectivity (if real) remains under investigation. Pair-feeding controls and pair-injected groups are used to separate direct metabolic effects from secondary changes in food intake.
Native human GH (191 AA) binds the GH receptor and produces both anabolic effects (via IGF-1 induction) and lipolytic effects. HGH Fragment 176-191 consists only of the C-terminal 16 amino acids responsible for lipolytic activity. It does not bind the GH receptor in standard competition assays and does not elevate IGF-1 at doses studied in preclinical models. This selectivity makes it a tool compound for isolating the lipolytic arm of GH biology from its growth-promoting and insulin-desensitising actions.
Yes — a disulfide bridge connects Cys-182 and Cys-189 within the fragment. This bond is structurally essential for activity: reduced (linear) forms of the peptide show significantly diminished lipolytic potency in adipocyte assays. When reconstituting or handling the peptide, avoiding strongly reducing conditions (e.g., high DTT concentrations) preserves the disulfide structure and thus biological activity in research assays.
The names HGH Fragment 176-191 and AOD-9401 refer to the same peptide sequence. AOD-9604 is a distinct compound — it includes an additional tyrosine residue at the N-terminus (Tyr-hGH(177–191)) and was the form advanced further in clinical obesity trials by Metabolic Pharmaceuticals. Research papers and supplier catalogues sometimes use these names interchangeably, but strictly they are different molecules. PeptidesFromChina.co lists AOD-9604 as a separate catalogue item.
HGH Fragment 176-191 is supplied at ≥98% purity, verified by RP-HPLC. Identity is confirmed by electrospray ionisation mass spectrometry (ESI-MS). A Certificate of Analysis from the synthesis facility is available for each batch. Wholesale pricing and minimum order quantities are provided on request after account verification.
For laboratory research use only. Not for human or veterinary use. PeptidesFromChina.co is a B2B wholesale supplier operating under strict research-use-only terms. All products are sold exclusively for in vitro and preclinical research purposes.