Disclaimer: Information provided is for research and educational purposes only. Sermorelin is not approved by the FDA or any regulatory agency for therapeutic or cosmetic use.

Introduction

Sermorelin (GHRH 1-29 NH₂) is a synthetic peptide fragment of growth hormone–releasing hormone (GHRH) — the natural signal the brain uses to stimulate growth hormone (GH) secretion¹ ². Originally developed in the 1980s, it became one of the first tools scientists used to study how GH pulses are regulated and how that process changes with age.³⁴. Unlike recombinant GH therapy, which delivers the hormone directly, sermorelin encourages the pituitary to release GH naturally, preserving the body’s feedback loops and pulse rhythm.⁵⁶

Fast Facts About Sermorelin

Property	Details
Sequence	First 29 amino acids of endogenous GHRH
Peptide Class	Synthetic GHRH analog
First Developed	Early 1980s
Mechanism	Stimulates the pituitary gland to release GH in a physiologic, pulsatile pattern⁴⁸
Common Study Areas	Endocrine modulation, body composition, aging research

Chemical Structure

Sermorelin is a synthetic peptide containing the first 29 amino acids of natural human growth hormone releasing hormone (GHRH or somatocrinin). This fragment retains the full biological activity of the 44-amino-acid GHRH while offering greater stability and ease of synthesis due to its length.

Sermorelin chemical structure and amino acid sequence

Discovery & Research Milestones

GHRH itself was identified in 1982 from human pancreatic tumor extracts that caused acromegaly¹².The discovery of its sequence led to the synthesis of shorter, biologically active fragments, the most successful being GHRH (1-29) NH₂ — later named sermorelin.³ ⁷

By the mid-1980s, clinical studies confirmed that sermorelin robustly increased GH levels in healthy men and women without significantly altering other pituitary hormones.⁴ ⁵ ⁶ Researchers also observed that sermorelin produced natural GH pulses, resembling the body’s normal nighttime secretion pattern.⁸

Year	Study & Source	Key Finding
1982	Rivier J. et al.; Guillemin R. et al.¹ ²	Human growth hormone–releasing hormone (GHRH) isolated from pancreatic tumors, establishing the native GH-releasing pathway.
1983-1984	Thorner M.O. et al.; Barron J.L. et al.³ ⁴	Shorter fragments synthesized; GHRH (1-29) NH₂ (later named Sermorelin) shown to retain full biological activity and safely stimulate GH in humans.
Late 1980s-1990s	Vance M.L.; Merimee T.J.; Khorram O.⁵ ⁸ ¹⁰	Clinical studies confirmed Sermorelin triggered pulsatile GH release matching physiologic rhythms and improved lean-to-fat ratios without excessive IGF-1 elevation.
1990s-2000s	Prakash A.; Walker R.F.¹¹ ¹²	Approved in 1997 as a diagnostic agent for pediatric GH deficiency, then withdrawn for commercial reasons in 2008.

How Sermorelin Works (In Brief)

Sermorelin binds to GHRH receptors in the pituitary, activating adenylyl cyclase and increasing cyclic AMP (cAMP) levels. This triggers the synthesis and pulsatile release of Growth Hormone, which then stimulates the liver and other tissues to produce insulin-like growth factor-1 (IGF-1).¹²

Why is Sermorelin Popular in Research?

1. Growth Hormone Stimulation: Mimics natural GHRH to trigger pulsatile GH release in adults and children with intact pituitary function.⁴ ⁷ ⁸ ⁹
   
2. Body Composition & Aging: Restores youthful GH rhythms and improves lean-to-fat ratios in older adults without excessive IGF-1 elevation.¹⁰
   
3. GH Deficiency Research: Studied as both a diagnostic agent and potential treatment for pediatric GH deficiency; well-tolerated in clinical use.¹¹
   
4. Mechanistic Insight: Serves as a reference model for studying how the brain and pituitary regulate GH secretion over the lifespan.¹²

Summary

Sermorelin (GHRH 1-29 NH₂) is a synthetic fragment of growth hormone–releasing hormone that stimulates the pituitary to secrete GH naturally. Discovered during the early mapping of human GHRH, it became a pivotal research tool for understanding GH regulation, sleep-related secretion, and aging. Although its use as a therapy waned with the advent of recombinant GH, sermorelin remains scientifically significant — offering a window into how the brain and pituitary coordinate growth hormone release throughout life.¹-¹²

FAQs About Sermorelin

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References

1. Rivier J, Spiess J, Thorner MO, Vale W. Characterization of a growth hormone-releasing factor from a human pancreatic islet tumour. Nature. 1982;300(5889):276-278. https://pubmed.ncbi.nlm.nih.gov/6292724/
   
2. Guillemin R, Brazeau P, Bohlen P, et al. Growth hormone-releasing factor from a human pancreatic tumor that caused acromegaly. Science. 1982;218(4572):585-587. https://pubmed.ncbi.nlm.nih.gov/6812220/
   
3. Thorner MO, Rivier J, Spiess J, Vance ML, Vale W. Human pancreatic growth-hormone-releasing factor (hpGRF-40) selectively stimulates GH secretion in normal men. Lancet. 1983;1(8321):24-28. https://pubmed.ncbi.nlm.nih.gov/6129370/
   
4. Barron JL, Hopkins KD, Dunger DB, Hesp R, White A. GHRH(1-29)-NH₂ and a D-Ala² analog are potent stimulators of GH release in normal men. Clin Endocrinol (Oxf). 1985;23(4):399-407.
   https://pubmed.ncbi.nlm.nih.gov/2866496/
   
5. Kopelman PG, Noonan K, Ginsburg J, White N. Low-dose GHRH(1-29)-NH₂ bolus and pulsed infusions: GH responses in normal-weight vs obese women. Clin Sci (Lond). 1986;70(5):531-538.
   https://pubmed.ncbi.nlm.nih.gov/2871950/
   
6. Vance ML, Kaiser DL, Frohman LA, et al. [Nle²⁷]GHRH(1-29)-NH₂ in normal men: IV, SC, and intranasal dosing stimulates GH without adverse effects. J Clin Endocrinol Metab. 1986;62(6):1242-1247.
   https://pubmed.ncbi.nlm.nih.gov/3096623/
   
7. Losa M, Schopohl J, von Werder K. Stimulation of GH with human GRF1-44, GRF1-40, and GRF1-29 in normal subjects (single-dose comparison). Klin Wochenschr. 1984;62(23):1109-1113.
   https://pubmed.ncbi.nlm.nih.gov/6240568/
   
8. Merimee TJ, Furlanetto R, et al. Pulsatile GH secretion induced by GHRH(1-29)-NH₂ (sermorelin) in man. J Clin Endocrinol Metab. 1988;66(3):541-544.
   https://pubmed.ncbi.nlm.nih.gov/3125487/
   
9. Spoudeas HA, Hindmarsh PC, Matthews DR, Brook CGD. Low-dose GRF(1-29)-NH₂ tests in adults: dose–response characteristics. Clin Endocrinol (Oxf). 1994;40(5):583-590.
   https://pubmed.ncbi.nlm.nih.gov/7921207/
   
10. Khorram O, Veldhuis JD, Iranmanesh A, et al. Nightly [Nle²⁷]GHRH(1-29)-NH₂ for 4 months in older adults: activation of the somatotropic axis and body-composition effects. J Clin Endocrinol Metab. 1997;82(5):1472-1479.
    https://pubmed.ncbi.nlm.nih.gov/9141536/
    
11. Prakash A, Goa KL. Sermorelin: review of diagnostic and therapeutic use (pediatric GH deficiency; dosing/response). BioDrugs. 1999;12(6):419-436.
    https://pubmed.ncbi.nlm.nih.gov/18031173/
    
12. Walker RF. Sermorelin: adult-onset GH insufficiency (editorial overview; open access). Clin Interv Aging. 2006;1(4):307-308.
    https://pmc.ncbi.nlm.nih.gov/articles/PMC2699646/