Summary

Sermorelin is a synthetic peptide consisting of the first 29 amino acids of naturally occurring growth hormone-releasing hormone (GHRH). It was originally FDA-approved as a diagnostic agent for growth hormone deficiency in children and has since attracted research interest for its potential to stimulate endogenous growth hormone production in a more physiological manner than direct GH administration. This profile covers its mechanism, the peer-reviewed evidence base, commonly discussed research protocols, and UK legal status.

Mechanism

Sermorelin is a synthetic analogue of the first 29 amino acids of human growth hormone-releasing hormone (GHRH 1–29). It binds to the GHRH receptor on somatotroph cells in the anterior pituitary gland, stimulating the synthesis and pulsatile release of endogenous growth hormone (GH). The released GH then acts on the liver to produce insulin-like growth factor 1 (IGF-1), which mediates many of GH's anabolic and metabolic effects. Unlike exogenous GH administration, sermorelin preserves the body's natural feedback loops: somatostatin can still inhibit GH release, and elevated IGF-1 provides negative feedback, potentially reducing the risk of oversuppression of endogenous GH production.

Evidence base

The strongest evidence for sermorelin relates to its diagnostic use in growth hormone deficiency testing, where it was FDA-approved. Studies in adults (Walker et al., 1998; Merriam et al., 2001, 2003) demonstrate GH and IGF-1 stimulation with preserved pulsatile secretion, but these are small, short-term studies. There are no large-scale RCTs examining long-term outcomes for body composition, metabolism, or anti-ageing effects.

Protocols

Research protocols in adults have used subcutaneous doses ranging from 0.5 µg/kg to 30 µg/kg, typically administered once daily at bedtime. Study durations have ranged from 14 days to 16 weeks. No standardised long-term dosing or cycling protocol has been established.

Sermorelin is not a Class C controlled substance in the UK and is not licensed as a medicinal product for human therapeutic use. It is legal to purchase and possess for bona fide research purposes. Sale for human consumption without MHRA licensing would be unlawful.

Vendor notes

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References

  1. Thorner MO, et al. Rapid communication: sustained stimulation of growth hormone (GH) by a GH-releasing factor (GRF) in man. Journal of Clinical Endocrinology and Metabolism. 1988.
  2. Walker RF, et al. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs. 1998;9(4):279-287.
  3. Merriam GR, et al. Sermorelin stimulation of growth hormone (GH) in older adults. Journal of the American Geriatrics Society. 2001.
  4. Merriam GR, et al. Effects of sermorelin on sleep architecture in older adults. Sleep. 2003.