Sermorelin Pen
6 mg of GHRH(1-29) amide in 3 mL of solution, about 2 mg/mL, in a 3 mL autoinjector pen. Filled from a peptide lot tested in the manufacturer’s own laboratory, with a certificate.
| Compound | Sermorelin GHRH(1–29)-NH₂; GRF(1–29) |
|---|---|
| CAS number | 86168-78-7 |
| Molecular formula | C149H246N44O42S |
| Theoretical mass | 3357.9 Da |
| Sequence / structure | H-YADAIFTNSYRKVLGQLSARKLLQDIMSR-NH₂ (29 residues; C-terminal amide) |
| Contents | Sermorelin: 6 mg per 3 mL pen (0.2% 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
- 6 mg · 1 pen — $88.99
- 6 mg · Kit of 10 — $791.12
Sermorelin is the 29-residue N-terminal stretch of human growth hormone-releasing hormone, amidated at its C-terminus. This listing is a preloaded autoinjector pen holding 6 mg of the peptide already dissolved in a 3 mL cartridge, about 2 mg/mL, so there is no powder to reconstitute. Research on sermorelin covers growth hormone release from the pituitary and clinical work in children and older men, and a separate set of papers maps how GRF peptides break down in water.
What is in the pen
The pen carries 6 mg of sermorelin in 3 mL of solution, which is 2 mg per mL. It is the same GHRH(1-29)-NH₂ that is sold freeze-dried in the Sermorelin 10 mg vial and the Sermorelin 5 mg vial, with the sequence and the 3357.9 Da theoretical mass shown in the specifications. Storage conditions are printed on the pen label. The concentration is fixed at filling, whereas a vial lets the laboratory choose its own volume of diluent. The general trade-offs between the two formats are set out in peptide pen vs vial.
Sermorelin in solution
A liquid format puts sermorelin in the state where it is least stable. Studies of GRF in water traced degradation to two sites: Asp3, which is cleaved from Ala4 in acid and isomerises above pH 4, and Asn8, which deamidates from about pH 5 upward; the peptide held up best between pH 4 and 51. Their temperature work ran from 22 to 55 °C, and between 22 and 37 °C the rate of Asn8 deamidation changed relatively little; refrigerator temperatures were not part of it1. In a related GRF analogue kept at neutral pH, the deamidated product lost 400 to 500-fold potency in pituitary cell assays2. Neither paper tested this pen's solution, so they explain the chemistry rather than set a shelf life.
What the research covers
Sermorelin, a 29-amino-acid analogue of human GHRH, is the shortest synthetic peptide with the full biological activity of the native hormone, and it stimulates growth hormone secretion specifically from the anterior pituitary3. In clinical work it served as a rapid, fairly specific diagnostic test for growth hormone deficiency in children, with fewer false positives than other provocative tests, although a normal result could not exclude deficiency of hypothalamic origin3. As a growth treatment, in an open-label multicentre study of 110 prepubertal children with the deficiency, it raised mean height velocity from 4.1 to 8.0 cm a year over six months without excess IGF-I or changes in fasting glucose4. In ten healthy older men, two weeks of GHRH(1-29) brought 24-hour growth hormone output and IGF-I up to the levels of nine young men, with no change in fasting glucose or blood pressure5.
The full literature, including the diagnostic data and what the trials left unresolved, is in the sermorelin research guide.
Frequently asked questions
How does the pen differ from the sermorelin vials?
The vials hold dry peptide that is stored at −20 °C and dissolved in the lab when needed, at whatever concentration the work calls for. The pen holds the same peptide already in solution at 2 mg/mL, so the concentration is fixed and the clock on solution stability starts at filling.
Do the stability papers say how long the pen keeps?
No. They studied GRF peptides in buffers between 22 and 55 °C and show which residues degrade and at what pH. They did not test this solution or refrigerated storage, so follow the storage conditions on the pen label.
References
- Bongers J, Heimer EP, Lambros T, et al. Degradation of aspartic acid and asparagine residues in human growth hormone-releasing factor. Int J Pept Protein Res. 1992;39(4):364-74. DOI · PubMed
- Friedman AR, Ichhpurani AK, Brown DM, et al. Degradation of growth hormone releasing factor analogs in neutral aqueous solution is related to deamidation of asparagine residues. Replacement of asparagine residues by serine stabilizes. Int J Pept Protein Res. 1991;37(1):14-20. DOI · PubMed
- Prakash A, Goa KL. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs. 1999;12(2):139-57. DOI · PubMed
- Thorner M, Rochiccioli P, Colle M, et al. Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy. Geref International Study Group. J Clin Endocrinol Metab. 1996;81(3):1189-96. DOI · PubMed
- Corpas E, Harman SM, Piñeyro MA, et al. Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men. J Clin Endocrinol Metab. 1992;75(2):530-5. 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.