Sermorelin: A Growth Hormone-Releasing Hormone Analog
Sermorelin is a 29-amino acid synthetic analog of growth hormone-releasing hormone (GHRH) that stimulates the pituitary gland to produce and release endogenous growth hormone. 1
Mechanism of Action
- Sermorelin is the shortest synthetic peptide with full biological activity of GHRH, specifically stimulating growth hormone secretion from the anterior pituitary 1
- It functions by mimicking the action of naturally occurring GHRH, which is produced by the hypothalamus to regulate growth hormone production 2
- Unlike exogenous growth hormone administration, sermorelin works by promoting the body's natural production of growth hormone 1, 2
Clinical Applications
Diagnostic Use
- Sermorelin can be used as a diagnostic test for growth hormone deficiency when administered as a single intravenous dose of 1 μg/kg bodyweight 1
- It produces a rapid and relatively specific test for diagnosing growth hormone deficiency with fewer false positives compared to other provocative tests 1
- However, normal growth hormone responses to intravenous sermorelin cannot completely exclude growth hormone deficiency due to hypothalamic deficit 1
Therapeutic Use
- Sermorelin has been used in the treatment of children with idiopathic growth hormone deficiency 1
- When administered subcutaneously at 30 μg/kg bodyweight at bedtime, it has shown effectiveness in promoting growth in prepubertal children with growth hormone deficiency 1
- Significant increases in height velocity have been observed during 12 months of treatment, with data suggesting maintained effect for up to 36 months of continued treatment 1
Administration
- For diagnostic purposes: intravenous administration at 1 μg/kg bodyweight 1
- For therapeutic purposes: subcutaneous administration at 30 μg/kg bodyweight, typically given at bedtime 1
- The short half-life (10-20 minutes in humans) necessitates regular administration 3
- PEGylated forms of sermorelin have been developed to extend its half-life and increase pharmacodynamic response 3
Limitations and Considerations
- Sermorelin has a short half-life of approximately 10-20 minutes in humans, primarily due to renal ultrafiltration and enzymatic degradation at the N-terminus 3
- Its effects on final adult height in children with growth hormone deficiency have not been fully determined 1
- The recommended dosage of sermorelin has not been directly compared with somatropin (recombinant human growth hormone) in controlled clinical trials 1
- Limited data suggest that increases in height velocity with sermorelin may be less than those achieved with somatropin at equivalent dosages 1
Safety Profile
- Sermorelin is generally well-tolerated in both single intravenous doses and repeated subcutaneous administrations 1
- The most commonly reported adverse events include transient facial flushing and pain at the injection site 1
- In men receiving sermorelin as part of growth hormone secretagogue treatment, significant increases in insulin-like growth factor-1 (IGF-1) levels have been observed 4
Research Applications
- Sermorelin has been investigated in combination with other growth hormone secretagogues like GHRP-2 and GHRP-6 to increase endogenous growth hormone levels 4
- Such combinations have shown the ability to increase serum IGF-1 levels with strict compliance to thrice-daily dosing 4
- This approach may be beneficial in individuals with wasting conditions that could improve with increased growth hormone secretion 4
I hope this provides a comprehensive overview of sermorelin and its clinical applications.