HGH Fragment 176-191 Pen
The native 16-residue C-terminal fragment of human growth hormone, 10 mg in 3 mL of bacteriostatic water. Filled from a peptide lot tested in the manufacturer’s own laboratory, with a certificate.
| Compound | hGH fragment 176-191 (Human growth hormone fragment 176-191 (FLRIVQCRSVEGSCGF; Cys182-Cys189 disulfide)) |
|---|---|
| CAS number | 66004-57-7 |
| Molecular formula | C78H123N23O22S2 |
| Contents | hGH fragment 176-191: 10 mg per 3 mL pen (0.33% w/v) |
| Form | Sterile aqueous solution in bacteriostatic water (0.9% benzyl alcohol), supplied in a 3 mL glass cartridge inside a preloaded autoinjector pen fitted with a needle |
| Storage, sealed | Store at 2–8 °C in the original carton, protected from light |
| Format | Solution in a 3 mL pre-filled pen |
Sizes and lots
- 10 mg · 1 pen — $58.99
- 10 mg · Kit of 10 — $524.42
HGH fragment 176-191 is the last sixteen residues of human growth hormone, FLRIVQCRSVEGSCGF, with the cysteines at hormone positions 182 and 189 joined by a disulfide. This listing is a preloaded autoinjector pen holding 10 mg of the native fragment dissolved in 3 mL of bacteriostatic water. Most research filed under this name was in fact done with AOD-9604, a close tyrosine-led analogue, and concerns fat metabolism and insulin sensitivity in obese rodents; the native sequence itself has barely been studied.
Which peptide is in this pen
What is in the pen
Each pen holds a 3 mL glass cartridge of sterile solution: 10 mg of the fragment at 0.33% w/v, about 3.3 mg/mL, in bacteriostatic water containing 0.9% benzyl alcohol as a preservative. The safety data sheet does not classify the peptide. It lists benzyl alcohol as harmful if swallowed or inhaled, a serious eye irritant and a possible skin sensitiser. Keep the pen at 2 to 8 °C in its carton, out of the light and capped between uses, and never let it freeze; discard a pen whose solution has frozen, discoloured or turned cloudy. The light warning has a basis in the sequence. Kerwin and Remmele list phenylalanine and cysteine or cystine among the residues that undergo primary photooxidation in proteins1, and this fragment has a phenylalanine at each end and a disulfide between them. General trade-offs between ready-made solutions and freeze-dried vials are covered in peptide pen vs vial.
What the research covers
Almost everything published under the fragment 176-191 name was done with AOD-9604. Ng and colleagues described that peptide as a synthetic analogue of the lipolytic domain of growth hormone and tested it in obese Zucker rats2. Over a 19-day oral study, treated rats gained less than half as much weight as controls, and their adipose tissue showed higher lipolytic activity2. Euglycaemic clamps found no adverse effect on insulin sensitivity, which set it apart from chronic treatment with intact growth hormone2.
Heffernan and colleagues then looked at mechanism in obese mice treated for 14 days3. Growth hormone and AOD-9604 both reduced body weight and body fat, and both brought the depressed beta-3 adrenergic receptor RNA of obese mice up to lean levels3. In beta-3 receptor knockout mice the long-term effects on body weight and lipolysis did not appear, yet in an acute experiment AOD-9604 still raised energy expenditure and fat oxidation3. The authors concluded that the lipolytic action was not mediated directly through the beta-3 receptor, though higher receptor expression might add to it3.
Frequently asked questions
Is this pen HGH fragment 176-191 or AOD-9604?
The native fragment. Its sequence begins with phenylalanine, FLRIVQCRSVEGSCGF, and the safety data sheet gives CAS 66004-57-7 and the formula C78H123N23O22S2. AOD-9604 begins with tyrosine instead, weighs about 16 Da more and has its own CAS number, even though sellers often use one name for both.
Why must the pen stay cold, dark and unfrozen?
Those are the conditions on the safety data sheet: 2 to 8 °C in the carton, protected from light, never frozen, and discarded if the solution freezes, discolours or clouds. The fragment's phenylalanines and its disulfide are among the groups that light can oxidise in peptides and proteins.
Does the published research apply to this pen?
Only as background. The rodent studies of fat metabolism and insulin sensitivity used AOD-9604, not the native fragment, and none tested a peptide in solution. The native sequence has no human study, so nothing here describes a demonstrated effect of this product.
References
- Kerwin BA, Remmele RL Jr. Protect from light: photodegradation and protein biologics. J Pharm Sci. 2007;96(6):1468-79. DOI · PubMed
- Ng FM, Sun J, Sharma L, et al. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Horm Res. 2000;53(6):274-8. DOI · PubMed
- Heffernan M, Summers RJ, Thorburn A, et al. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology. 2001;142(12):5182-9. DOI · PubMed
For laboratory research use only. Not for human or veterinary consumption. Products have not been evaluated by the U.S. Food and Drug Administration and are not intended to diagnose, treat, cure or prevent any disease.