Sermorelin — Complete Research Guide (2026)

Last updated 2026-06-25

What is Sermorelin?

Sermorelin is a synthetic 29-amino-acid peptide corresponding to the biologically active 1-29 fragment of human growth-hormone-releasing hormone (GHRH), historically marketed as the prescription product Geref and used mainly as a diagnostic agent for growth-hormone (GH) deficiency and as a pediatric growth treatment.

It is no longer a widely marketed pharmaceutical and is presented here for research and educational purposes only, not as a therapy.

Its human evidence base is small but real, consisting of older controlled trials in GH-deficient children and in aging adults; it is not an approved anti-aging or performance product.

How does Sermorelin work?

Sermorelin binds GHRH receptors on anterior-pituitary somatotrophs, stimulating synthesis and pulsatile release of endogenous growth hormone, which in turn raises insulin-like growth factor-1 (IGF-1).

Because it works upstream through the pituitary, GH output remains subject to normal negative feedback and somatostatin tone rather than bypassing them. [INFOGRAPHIC: GHRH-receptor stimulation of pituitary GH release]

What does the research say about Sermorelin?

• In healthy older men, nightly subcutaneous GHRH(1-29) raised nocturnal GH release and improved some measures of skeletal-muscle strength and endurance. ^[1]
• Twice-daily GHRH-(1-29) reversed age-related declines in GH and IGF-1 in older men, moving levels toward those of younger men. ^[2]
• Four months of nightly GHRH analog administration increased lean body mass and insulin sensitivity in age-advanced men (with mainly skin-thickness changes in women). ^[3]

Clinical research & studies

The references below are the primary sources cited throughout this guide. Each links directly to PubMed or the regulator. Where evidence is preclinical (animal or in-vitro), that is stated rather than implied.

• [1] Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men — Vittone J et al., Metabolism 1997. (human clinical (healthy elderly men))
• [2] Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men — Corpas E et al., J Clin Endocrinol Metab 1992. (human RCT (older men))
• [3] Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women — Khorram O et al., J Clin Endocrinol Metab 1997. (human RCT (4-month; Nle27-modified analog))
• [4] Pharmacokinetics of growth hormone-releasing hormone(1-29)-NH2 and stimulation of growth hormone secretion in healthy subjects after intravenous or intranasal administration — Wilton P et al., Acta Paediatr Suppl 1993. (human PK study)
• [5] Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency — Prakash A et al., BioDrugs 1999. (narrative review)

Dosing context

Published human studies used small, weight-based amounts (for example roughly 1 microgram/kg intravenously as a single diagnostic provocation, or nightly subcutaneous injections in the aging-adult trials).

These figures describe what researchers administered under medical supervision and are not dosing guidance; sermorelin is presented here strictly as a research compound.

Side effects & safety profile

In its clinical trials and diagnostic use sermorelin was generally well tolerated, with the most common issues being transient injection-site reactions, flushing, and occasional headache.

Because it amplifies the body's own GH axis rather than delivering exogenous GH, supraphysiological IGF-1 levels were generally not seen in the aging-adult studies, but long-term safety in healthy adults is not established.

No sermorelin product is currently broadly approved or marketed for anti-aging use; any use outside a regulated diagnostic or pediatric-deficiency setting is investigational.

Stacking & combinations

In research settings GHRH analogs like sermorelin have been combined with GH-releasing peptides (ghrelin-receptor agonists) to study synergistic GH release, but such combinations are experimental and not validated for any consumer use.

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References

1. [1] Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men — Vittone J et al., Metabolism 1997. PMID: 9005976. View sourceStudy: human clinical (healthy elderly men)Nightly GHRH(1-29) increased nocturnal GH release and improved some muscle strength/endurance measures.
2. [2] Growth hormone (GH)-releasing hormone-(1-29) twice daily reverses the decreased GH and insulin-like growth factor-I levels in old men — Corpas E et al., J Clin Endocrinol Metab 1992. PMID: 1379256. View sourceStudy: human RCT (older men)Twice-daily GHRH-(1-29) reversed age-related declines in GH and IGF-I.
3. [3] Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women — Khorram O et al., J Clin Endocrinol Metab 1997. PMID: 9141536. View sourceStudy: human RCT (4-month; Nle27-modified analog)Nightly GHRH analog increased lean mass and insulin sensitivity in men; women showed mainly increased skin thickness.
4. [4] Pharmacokinetics of growth hormone-releasing hormone(1-29)-NH2 and stimulation of growth hormone secretion in healthy subjects after intravenous or intranasal administration — Wilton P et al., Acta Paediatr Suppl 1993. PMID: 8329825. View sourceStudy: human PK studyCharacterized the short plasma half-life of GHRH(1-29)-NH2 and GH stimulation after IV or intranasal dosing.
5. [5] Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency — Prakash A et al., BioDrugs 1999. PMID: 18031173. View sourceStudy: narrative reviewReviews sermorelin as a provocative diagnostic test and treatment for idiopathic GH deficiency in children.

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