Sermorelin 5mg

What is Sermorelin ?

Sermorelin, also sold as sermorelin acetate or GRF (1-29), is the first 29 amino acids of human growth-hormone-releasing hormone (GHRH) with a C-terminal amide. It is the shortest synthetic peptide with the full biological activity of GHRH. Each Sermorelin 5mg vial holds white lyophilised powder.

Sermorelin binds the GHRH receptor on somatotroph cells of the anterior pituitary and stimulates growth hormone secretion (Prakash and Goa, BioDrugs, 1999). Native GHRH has 44 residues, so sermorelin keeps the active region and drops the C-terminal third.

It was once a licensed medicine. As Geref it served as a diagnostic test of pituitary growth hormone reserve and was studied in children with idiopathic growth hormone deficiency. It was later withdrawn for commercial reasons, not because of a safety finding. No sermorelin product holds a UK marketing authorisation today.

Sermorelin Research Applications

• GHRH receptor pharmacology : the reference GHRH (1-29) agonist in somatotroph signalling and pituitary growth hormone release models.
• Analogue benchmarking : the native fragment that modified GRF (1-29) and CJC-1295 are built from.
• Ipamorelin vs sermorelin : ipamorelin acts at the ghrelin receptor, GHS-R1a, while sermorelin acts at the GHRH receptor.
• Tesamorelin vs sermorelin : both are GHRH receptor agonists, but tesamorelin keeps all 44 residues of GHRH and adds a trans-3-hexenoyl group to block enzymatic cleavage.

The human literature is diagnostic. Prakash and Goa reviewed sermorelin as a rapid and relatively specific test for growth hormone deficiency, with fewer false positives than other provocative tests. Walker (Clin Interv Aging, 2006) is a perspective article on adult growth hormone insufficiency, not a trial report.

Sermorelin vs Modified GRF (1-29)

Both use the same 29-residue backbone and the same receptor. Sermorelin is the unmodified human sequence, with three known weak points. The Tyr-Ala start is cut by dipeptidyl peptidase-4, asparagine 8 deamidates and methionine 27 oxidises. Modified GRF (1-29), also sold as CJC-1295 without DAC, swaps four residues (D-Ala2, Gln8, Ala15, Leu27) to close those routes. CJC-1295 with DAC adds an albumin-binding group on top. Sermorelin is the fragment characterised in the human diagnostic literature, so findings made with it map straight onto native GHRH (1-29). Each substitution in an analogue adds a variable.

Research Overview

Sermorelin, also written sermorelin acetate and catalogued as GRF (1-29)-NH₂, GHRH (1-29) or hGRF(1-29), is a synthetic 29-residue peptide amide corresponding to the first 29 amino acids of human growth-hormone-releasing hormone, the shortest fragment of the native 44-residue hormone that retains full biological activity. Its one-letter sequence is YADAIFTNSYRKVLGQLSARKLLQDIMSR-NH₂, molecular weight 3357.9 g/mol, CAS number 86168-78-7. That 1-29 backbone is the parent scaffold of an entire family of GHRH analogues, modified GRF (1-29), CJC-1295 and related compounds are all substitution products of this exact sequence, which makes unmodified sermorelin the natural reference compound for GHRH-axis research. Pharmacologically, sermorelin binds the growth-hormone-releasing-hormone receptor on anterior pituitary somatotrophs and stimulates the release of endogenous growth hormone. What genuinely separates sermorelin from nearly everything else in this catalogue is its regulatory history: it was a licensed medicine. Marketed as Geref, sermorelin acetate was used as a provocative diagnostic agent for assessing pituitary growth hormone reserve and was studied in children with idiopathic growth hormone deficiency, a clinical literature reviewed in detail by Prakash and Goa (BioDrugs, 1999). The product was later withdrawn from the market for commercial reasons rather than because of any safety finding, and no sermorelin product currently holds a marketing authorisation in the UK or elsewhere. Walker (Clin Interv Aging, 2006) discussed sermorelin as a tool for studying the GHRH axis in adult-onset growth hormone insufficiency, though that paper is a perspective piece rather than trial data, and the honest position is that applications beyond the characterised diagnostic pharmacology remain unestablished. Chemically, the sequence carries a methionine at position 27, the oxidation-prone residue that dictates careful handling and storage. Each vial contains 5mg of sermorelin as white lyophilised powder, batch UKPL-780, verified at 99.3% purity by RP-HPLC, with the certificate of analysis published on this page. Supplied strictly for in-vitro laboratory research use only.

Storage and Reconstitution

Keep sealed vials at -20°C, away from light and moisture. After reconstitution, keep the solution at 2-8°C and use it within 4 weeks, or freeze single-use aliquots at -20°C. Oxidation of methionine 27 is the degradation route to guard against. Keep vials tightly sealed with little headspace and away from oxidising agents.

Vials are sold on their own, without bacteriostatic water for mixing or other supplies.

How to reconstitute and handle

Bring the vial to room temperature and swab both stoppers with alcohol. Add bacteriostatic water slowly down the inside wall of the vial and swirl gently until dissolved. Do not shake or vortex: a 29-residue peptide is shear-sensitive. The solution should be clear and colourless. Methionine 27 oxidises in air, so work quickly and reseal promptly. Label the vial with the date and refrigerate.

• The methionine at position 27 is the oxidation-prone residue of the sequence. Keep solutions away from oxidising agents, minimise the time vials stand open to air, and re-seal promptly after each draw.

For the full method, see the peptide reconstitution guide and the reconstitution calculator.

Research References

• Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency (Prakash and Goa, BioDrugs, 1999)
• Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? (Walker, Clin Interv Aging, 2006)

Published research on Sermorelin is indexed on PubMed. See our full UK buyer's guide for Sermorelin and UK buyer's guide for Sermorelin 5mg.