HGH Fragment 176-191

For Laboratory Research Use Only — Not for Human or Veterinary Use.

Standard (< 1,000 vials)$240/kit

Volume (1,000+ vials)$140/kit

Quantity (kits)

= 10 vials

Minimum order: 100 vials total. Mix and match across all products.

I confirm this order is for laboratory research use only.For Laboratory Research Use Only — Not for Human or Veterinary Use. By checking this box you affirm this product will not be used for human or animal administration.

Specifications

CAS Number	66004-57-7
Molecular Formula	C78H123N23O22S2
Molecular Weight	1799.10 g/mol
Purity	≥98% (HPLC)
Form	Lyophilized Powder
Storage	-20°C, desiccated, protected from light
Reconstitution	Bacteriostatic water

Certificate of Analysis

Lot documentation

Every production lot is independently third-party tested. A batch-specific Certificate of Analysis — documenting HPLC purity, mass spectrometry identity confirmation, and net peptide content — is issued with every shipment. View a sample COA to see the format.

View Sample COA About our testing →

Research context

The unmodified C-terminal fragment of the growth hormone sequence, distinguished from AOD-9604 by the absence of an added N-terminal tyrosine. Supplied lyophilised, with disulfide integrity verified per lot.

Structure and origin

This is the 16-residue peptide corresponding to residues 176 to 191 of the growth hormone polypeptide, supplied without modification. It carries the intramolecular disulfide bridge present in the corresponding region of the intact hormone, forming a small constrained loop.

It is closely related to AOD-9604 and the two are frequently conflated. The distinction is a single residue: AOD-9604 is this fragment with a tyrosine appended at the N-terminus, introduced in the originating work to permit radioiodination for tracer studies. The two therefore differ by 163 daltons and are readily distinguished analytically, but the names are used loosely enough in supplier catalogues that confirming which molecule a lot actually contains is worthwhile.

Findings in the published research literature

The reported interest in this region of the hormone rests on the observation that lipolytic signalling attributed to the intact molecule is retained by the C-terminal fragment, while the growth-promoting and insulin-antagonising activity is not, since the determinants for growth hormone receptor binding lie outside residues 176 to 191.

Isolated adipocyte preparations form the core of the in-vitro literature, with glycerol release as the standard readout for lipolytic signalling. Because much of the published work uses the tyrosine-extended analog rather than the unmodified fragment, attributing a given finding to the correct molecule requires care when reading this literature.

Analytical verification

Reversed-phase HPLC establishes purity and mass spectrometry confirms identity, reported per lot on the Certificate of Analysis. Mass is the attribute that separates this molecule from AOD-9604, and confirming it against the expected value for the unextended fragment is the first check worth making.

Because the sequence is cysteine-containing, disulfide status is the release attribute that matters most. The reduced linear form differs by only two daltons and is reported as inactive in the relevant assay systems, while intermolecular disulfide-linked dimers are a separate and separately detectable failure mode. Non-reducing peptide mapping distinguishes correctly bridged material from reduced and scrambled variants.

Handling and storage

Solubility	Soluble in water and neutral aqueous buffer.
Reconstitution	Dissolves readily with gentle swirling.
Storage	Lyophilised powder at -20C, desiccated. Reconstituted solution at 2-8C.
Stability	Avoid thiol reducing agents such as dithiothreitol or tris(2-carboxyethyl)phosphine in any buffer used with this peptide; they will open the disulfide loop and abolish activity in the reported assay systems.