Sermorelin (Geref)
Sermorelin acetate (GHRH(1-29)-NH2; GRF(1-29)-NH2)
A synthetic 29-amino acid analog of endogenous human GHRH that stimulates pituitary growth hormone release. Previously FDA-approved for pediatric GH deficiency (Geref, discontinued 2008 for commercial reasons); now used primarily via compounding pharmacies for adult anti-aging, body composition, and sleep improvement.
Last updated: 2026-03-12
Safety Summary
Overall adverse effect profile is mild. Majority of events are transient and resolve with continued use. SAEs were rare in published trials. The development of anti-sermorelin antibodies is common but has not been associated with reduced efficacy or increased side effects in clinical trials. Related analog tesamorelin showed ~50% anti-drug antibody seropositivity without clear efficacy or safety impact. When combined with GHRPs, additional effects may include increased appetite (GHRP-6), occasional changes in cortisol/prolactin. Long-term chronic GH stimulation carries theoretical cancer risk (via IGF-1 elevation), but no causal link to sermorelin-specific cancer promotion established. No classical dependence/withdrawal syndrome documented.
Known Side Effects
Very common (most frequent complaint)
Common
Common
Common
Common
Common
Uncommon
Uncommon
Uncommon
Rare
Who Should NOT Use This
GH/IGF-1 axis stimulation could potentially promote the growth of existing tumors.
Risk of severe allergic/anaphylactic reaction.
Pituitary stimulation may complicate intracranial pathology.
Adequate thyroid hormone level is necessary for optimal GH response to sermorelin. Must be corrected first.
GH axis stimulation can worsen glycemic control.
No adequate human data; theoretical fetal risk from GH/IGF-1 stimulation.
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Systemic glucocorticoids suppress GH axis and can blunt sermorelin response.
Talk to Your Doctor
Before considering Sermorelin (Geref), discuss it with your healthcare provider. Ask about potential interactions with your current medications, whether it is appropriate for your health conditions, and what monitoring may be needed.
Sources: [1-5]
Evidence Assessment
Previously FDA-approved (Geref, NDA 019863, ~1991) for pediatric GH deficiency, supported by Phase 2/3 pediatric trial data. Product voluntarily discontinued in 2008 for commercial reasons, not safety/efficacy. No currently marketed FDA-approved product. Adult evidence is limited: one small placebo-controlled RCT (n=19, Khorram et al.). one cognitive function RCT (Friedman et al. 2013, PMC3764915), and small open-label studies. No Phase 3 RCTs in adult populations for current off-label indications (anti-aging, body composition). No active clinical trials on ClinicalTrials.gov. Prior FDA approval elevates above Tier 4, but absence of current approval, small adult sample sizes, and lack of large-scale RCTs for current uses prevent Tier 2. RECONCILIATION NOTE: Opus assigned Tier 4 (emphasizing discontinued status, lack of adult RCTs); Gemini assigned Tier 2 (emphasizing prior FDA approval history). Tier 3 represents the conservative middle ground.
1Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and womenPMID 9141536
Khorram O, Laughlin GA, Yen SS - J Clin Endocrinol Metab (1997) - Single-blind, randomized, placebo-controlled trial - 19
Nightly sermorelin (10 mcg/kg SC) for 16 weeks in elderly subjects (55-71) produced significant increases in nocturnal GH, IGF-1, IGFBP-3, skin thickness, and lean body mass in men. No serious adverse events.
Limitations: Very small sample (n=19); single-blind design; no CIs reported; short duration; gender differences in response. Used a slightly modified analog ([Nle27] substitution).
2Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiencyPMID 18031173
Prakash A, Goa KL - BioDrugs (review) (1999) - Review of pediatric trials
Sermorelin stimulated endogenous GH and increased height velocity vs baseline/placebo in GH-deficient children. Height velocity gains were generally smaller than with recombinant human GH (somatropin).
Limitations: Review article; individual trial details and CIs not consistently available. Highlights lower efficacy vs rhGH standard of care.
3Growth Hormone-Releasing Hormone Effects on Brain GABA Levels in Mild Cognitive Impairment and Healthy Aging
Friedman SD et al. - JAMA Neurology (2013) - Randomized, placebo-controlled clinical trial
Sermorelin treatment for 20-26 weeks in older adults with and without mild cognitive impairment resulted in statistically significant improvements in fluid intelligence and memory compared to placebo. Cognitive improvements associated with brain GABA level changes.
Limitations: Single study requiring replication. Long-term durability of cognitive benefits unknown. Sample size not specified in available data.
4Pharmacokinetics of growth hormone-releasing hormone(1-29)-NH2 and stimulation of growth hormone secretion in healthy subjects after intravenous or intranasal administrationPMID 8329825
Wilton P et al. - Clin Pharmacol Ther (1993) - PK/PD study
IV produced rapid GH rise. Intranasal absorption low with estimated absolute bioavailability ~3-5%. Dose-dependent GH release via both routes.
Limitations: Small cohort; PK confidence intervals not consistently reported.
5Geref (sermorelin acetate) FDA NDA and Orphan Drug Designation
FDA/EMD Serono - FDA regulatory filing (1991) - NDA (regulatory filing including pediatric trials)
FDA approval for diagnostic and therapeutic use in pediatric GH deficiency based on multiple pediatric randomized trials demonstrating GH stimulation and growth acceleration.
Limitations: Product voluntarily discontinued 2008; original trial data not fully accessible in public domain.