Sermorelin: Clinical Use and Dosing
Critical Limitation: Sermorelin is NOT Recommended for Growth Hormone Deficiency Treatment
Sermorelin is not the therapy of choice for growth hormone deficiency in either children or adults—recombinant human growth hormone (rhGH) at 0.045-0.05 mg/kg/day is the recommended treatment, not sermorelin. 1
Current Clinical Role of Sermorelin
Diagnostic Use Only
Sermorelin's primary validated role is as a diagnostic test for growth hormone deficiency, not as a therapeutic agent:
- Intravenous sermorelin 1 mcg/kg bodyweight serves as a rapid and relatively specific provocative test for diagnosing GH deficiency 2
- Produces fewer false-positive responses compared to other provocative tests 2
- Important caveat: Normal GH response to sermorelin cannot exclude GH deficiency due to hypothalamic deficits; subnormal responses to other provocative tests are needed to confirm disease in these patients 2
Limited Therapeutic Data (Historical Context)
While older research explored sermorelin for treatment, the evidence is insufficient to support its use over standard rhGH therapy:
Dosing regimen studied (not recommended for routine use):
- 30 mcg/kg bodyweight subcutaneously once daily at bedtime in prepubertal children with idiopathic GH deficiency 2
- Alternative regimens studied: twice-daily subcutaneous injections 3
Efficacy concerns:
- Height velocity increases with sermorelin (30 mcg/kg/day as continuous infusion or 3 divided doses) were less than those achieved with once-daily subcutaneous somatropin 30 mcg/kg/day 2
- Only 8 of 18 GH-deficient children showed worthwhile growth response (defined as height velocity increase >2 cm/year) 3
- Response was unpredictable: 4 of 14 patients previously responsive to hGH showed growth deceleration on sermorelin for unknown reasons 3
Predictors of response (if sermorelin were to be used):
- Peak serum GH response >30 mU/L during IV GHRH test predicted good growth response, though lower peaks did not preclude response 3
- Slow-growing, shorter children with delayed bone and height age appeared to respond better 2
Safety Profile
Sermorelin is well-tolerated with minimal adverse events:
- Transient facial flushing (most common) 2
- Pain at injection site 2
- Anti-GHRH antibodies developed in 14 of 18 patients but did not adversely affect growth or GH responses 3
Why Recombinant GH is Preferred
Standard treatment for GH deficiency:
- Dose: 0.045-0.05 mg/kg/day subcutaneously 4, 5, 1
- Administered as daily evening injections to mimic physiological circadian rhythm 4
- Injection site should be changed daily to avoid lipoatrophy 4
- Both reference products and biosimilars are appropriate 4
Monitoring requirements for GH therapy (every 3-6 months):
- Height and growth velocity 5
- Pubertal development 5
- Skeletal maturation via wrist radiography 5
- Thyroid function (TSH, free T3) 5
- Metabolic parameters: glucose, calcium, phosphate, bicarbonate 5
Contraindications to GH therapy:
- Closed epiphyses 4, 5
- Active malignancy 4, 5
- Acute critical illness 4, 5
- Severe secondary hyperparathyroidism (PTH >500 pg/mL) 4, 5
- Known hypersensitivity to active substance or excipients 4, 5
Bottom Line
Sermorelin has a narrow diagnostic role but should not be used therapeutically when recombinant GH is available and proven superior. The evidence base for sermorelin treatment is limited to small, older studies showing inferior efficacy compared to standard rhGH replacement therapy.