Sermorelin

Sermorelin is a synthetic 29-amino acid peptide constituting the biologically active N-terminal fragment of human growth hormone-releasing hormone (GHRH). Despite representing only positions 1 through 29 of the 44-residue parent molecule, this fragment retains essentially full agonist activity at the GHRH receptor (GHRHR).

Upon subcutaneous administration, sermorelin binds to GHRHR on somatotroph cells of the anterior pituitary gland. Receptor engagement activates a Gs-coupled adenylyl cyclase, elevating intracellular cyclic AMP (cAMP) and initiating protein kinase A signaling. This cascade stimulates both the synthesis and pulsatile secretion of endogenous growth hormone (GH).

A key feature distinguishing sermorelin from exogenous recombinant GH is that the hypothalamic-pituitary negative feedback loop remains intact. Somatostatin continues to modulate GH release, preventing sustained supraphysiologic concentrations and reducing the tachyphylaxis risk associated with direct GH administration. Released GH acts primarily on the liver to drive insulin-like growth factor-1 (IGF-1) production, which mediates downstream anabolic and metabolic effects including protein synthesis, lipolysis, and tissue regeneration.

• Receptor: GHRH receptor (GHRHR) on anterior pituitary somatotrophs • Signal transduction: Gs/cAMP/protein kinase A axis • Output: pulsatile endogenous GH release, downstream IGF-1 induction • Regulation: preserved somatostatin feedback distinguishes it from exogenous rhGH

Sermorelin completed the full FDA drug development pathway. Geref was approved in 1990 as a diagnostic agent and in 1997 for treating idiopathic growth hormone deficiency (GHD) in children with growth failure. The manufacturer voluntarily discontinued it in 2008 for commercial reasons; a 2013 Federal Register determination confirmed the withdrawal was not due to safety or efficacy concerns.

The most rigorous adult study is Khorram et al. (1997, Journal of Clinical Endocrinology and Metabolism), a single-blind, randomized, placebo-controlled trial in 19 age-advanced adults (55-71 years). Participants received a sermorelin analog ([Nle27]GHRH-(1-29)-NH2, a close structural variant) at 10 mcg/kg subcutaneously nightly for 16 weeks following a 4-week placebo run-in. Treatment produced statistically significant increases in 12-hour integrated nocturnal GH (P < 0.05 men; P < 0.01 women) and significant rises in serum IGF-I and IGFBP-3 within two weeks. In men, lean body mass increased significantly (P < 0.05) and insulin sensitivity improved; these effects were not replicated in women.

Corpas et al. (1992, JCEM, PMID 1639955; cited in Sinha et al. 2020) examined 10 elderly men (60-78) in a twice-daily 14-day cycling protocol at 0.5 or 1 mg per dose, finding dose-dependent GH and IGF-1 increases.

Research reviewed by Vitiello et al. (2001, Dialogues in Clinical Neuroscience) described a 5-6 month nightly sermorelin acetate regimen in older adults that approximately doubled 24-hour GH secretion and raised IGF-I by up to 40% in men, with roughly 5% reduction in body fat and a reciprocal lean mass increase. A cohort of 75 older adults showed 5-7% improvement on cognitive tasks measuring psychomotor and perceptual processing speed; sleep quality showed a small but statistically significant deterioration rather than improvement.

Evidence for performance and anti-aging applications in healthy adults remains preliminary, derived from small, short-duration trials conducted predominantly in elderly populations.

Typical dosage: 200-500 mcg (daily before bed).

The FDA-approved pediatric dose for Geref was 0.02 to 0.04 mg/kg once daily subcutaneously before bedtime, adjusted according to growth response and IGF-I monitoring.

Research protocols in adults employed considerably higher doses: Khorram et al. administered approximately 10 mcg/kg nightly (roughly 0.7-1 mg in a 70-100 kg adult) for 16 weeks; Corpas et al. used 0.5 mg or 1 mg twice daily in 14-day on / 14-day off cycles; Vittone et al. (cited in Sinha et al. 2020) used 2 mg subcutaneously nightly for 6 weeks.

In current compounding pharmacy practice, adults are typically initiated at 0.2 to 0.3 mg (200-300 mcg) subcutaneously once daily at bedtime. Evening timing aligns with the natural circadian GH secretion peak and avoids attenuation by post-meal insulin. Clinical protocols of 3 to 6 months are commonly reported, though no controlled data establish an optimal cycle length for adult off-label use.

Administration is subcutaneous; the original intravenous diagnostic formulation is no longer commercially available. Rotation of injection sites is recommended to prevent lipodystrophy.

This information is educational only and does not constitute medical advice. Sermorelin is not currently FDA-approved and is available only via compounding pharmacies in the United States; any use requires physician oversight, including monitoring of thyroid function and serum IGF-1.

Lyophilized (before reconstitution)

Multiple vendor sources cite roughly 24 months at −20°C for Sermorelin lyophilized powder, with a similar profile to CJC-1295/Ipamorelin. Refrigerated (2–8°C) storage is acceptable for shorter active-use windows. Same GH-secretagogue class behavior; no peptide-specific divergence was surfaced in the vendor consensus. Keep dry, sealed, and away from light.

Reconstituted

Commonly cited at ~28 days refrigerated (2–8°C) in bacteriostatic water. Never freeze a reconstituted vial. This is a vendor-derived convention rather than a peptide-specific stability study — the window traces to the 0.9% benzyl alcohol preservative's antimicrobial validation, not to a Sermorelin-specific assay. See the Storage & handling primer for context.

For general storage chemistry (bacteriostatic vs sterile water, freeze-thaw, BUD framework), see Storage & handling.

Last reviewed: July 1, 2026

The most pharmacologically studied combination pairs sermorelin with growth hormone-releasing peptides (GHRPs), particularly GHRP-2 and GHRP-6. These peptides act at the ghrelin receptor (GHS-R1a), signaling through phospholipase C and intracellular calcium, a pathway mechanistically complementary to the cAMP cascade driven by GHRH receptor agonism. Preclinical evidence indicates that inhibition of endogenous GHRH substantially attenuates the GH response to GHRP-6, suggesting the two pathways are interdependent. A small retrospective study in 14 hypogonadal men (described in Sinha et al. 2020, PMC7108996) combining sermorelin with GHRP-2 and GHRP-6 at 100 mcg each three times daily observed statistically significant IGF-1 increases from a mean of 159.5 to 239.0 ng/mL; the absence of a control group and small sample size substantially limit conclusions.

Sermorelin combined with ipamorelin, a selective GHS-R1a agonist with minimal cortisol or prolactin stimulation, is widely used in hormone optimization clinics. No published controlled trial data exist for this specific pairing; reports of improved lean body mass and recovery are anecdotal, based on practitioner and patient experience only.

Sermorelin is not currently FDA-approved for any indication. It is generally classified as a research compound. Regulatory status varies by country.

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Reported side effects: Minimal side effects, injection site reactions

From the Geref prescribing information reflecting FDA pivotal trial data, injection site reactions (pain, swelling, redness) occurred in approximately 1 in 6 patients and were the most common adverse event. Other treatment-related events occurred at rates below 1% individually: headache, flushing, dysphagia, dizziness, hyperactivity, somnolence, and urticaria.

Hypothyroidism occurred in 6.5% of clinical trial participants; thyroid function monitoring is required during treatment. A large proportion of patients developed anti-GRF antibodies at some point during therapy; this was not consistently associated with altered growth outcomes or a distinct adverse reaction profile.

Khorram et al. (1997) noted transient hyperlipidemia that resolved by the end of the study period. Concomitant glucocorticoid therapy is documented to inhibit the pituitary GH response to sermorelin.

Sermorelin is contraindicated in patients with known hypersensitivity to the drug or any excipient. It has not been studied in patients with GHD secondary to intracranial lesions, and use in this population is not recommended.

Because sermorelin amplifies endogenous rather than exogenous GH, peripheral edema and arthralgias commonly associated with supraphysiologic rhGH dosing appear less frequently in trial data. Potential long-term risks from GH-axis overactivation, including insulin resistance and cardiovascular effects, cannot be excluded at doses exceeding those in published research. Quality and sterility variability inherent to compounded preparations represents an additional, unquantified safety concern not present under FDA-regulated manufacturing.