Also known as: GRF 1-29, Sermorelin acetate, Geref
Half-life: ~12 minutes
Last reviewed: · Published:
Sermorelin is a synthetic analog of the first 29 amino acids of endogenous growth-hormone-releasing hormone (GHRH 1-29), the shortest fragment that retains full biological activity. It binds to the GHRH receptor on the anterior pituitary and stimulates the synthesis and pulsatile release of natural growth hormone. Because Sermorelin works upstream of GH itself — by amplifying the body's own pulses rather than replacing the hormone — it preserves the negative-feedback loop and is far less likely to cause the suppression, elevated IGF-1 spikes, and side effects associated with exogenous recombinant HGH (somatropin).
Sermorelin was historically marketed as Geref (Serono) and approved by the FDA in 1997 for the diagnosis and treatment of growth hormone deficiency in children. The branded product was discontinued in 2008 for commercial reasons, not safety. Compounded Sermorelin remains widely prescribed in age-management and longevity clinics in the United States as a legal off-label alternative to HGH. It has a very short half-life (~12 minutes), which closely mirrors endogenous GHRH and necessitates either bedtime dosing or pairing with a ghrelin-receptor agonist such as Ipamorelin.
Compared to newer GHRH analogs like CJC-1295 (Mod GRF 1-29), Sermorelin has a shorter duration of action because it lacks the modifications that protect against dipeptidyl peptidase-4 (DPP-4) cleavage. This shorter window is sometimes considered a feature rather than a flaw: the GH pulse is brief and physiological, more closely resembling the body's natural rhythm.
Sermorelin was developed in the early 1980s following the 1982 identification and sequencing of human GHRH by Roger Guillemin and colleagues, who later shared the Nobel Prize for related work. Researchers found that the first 29 amino acids of the 44-residue native hormone retained full intrinsic GH-releasing activity. The compound was developed by Serono Laboratories and approved by the FDA in 1997 under the brand name Geref for pediatric growth hormone deficiency, making it one of the first peptide GH secretagogues to reach clinical use. Serono withdrew the product in 2008. Compounded Sermorelin has since become a staple of US anti-aging and hormone-optimization practice.
Sermorelin has an excellent long-term safety profile and is generally considered the gentlest of the GH secretagogues. Because it amplifies the body's own GH pulses rather than overriding them, IGF-1 elevations stay within physiological range and tachyphylaxis (receptor desensitization) is uncommon when dosed appropriately. The most frequent side effect is mild injection-site reaction. Unlike exogenous HGH, Sermorelin does not typically cause carpal tunnel symptoms, edema, or significant blood-glucose disruption at therapeutic doses.
Dose Range
200-500 mcg
Frequency
Once daily before bed (SubQ)
Duration
3-6 months, then reassess
Dose Range
200-300 mcg of each
Frequency
Once daily before bed
Duration
3-6 months
Dose Range
30 mcg/kg
Frequency
Once daily before bed
Duration
Per endocrinologist
Dosing information is for educational purposes only. Consult a healthcare professional before using any peptide.
Typical Vial Size
5 mg
Water Type
Bacteriostatic water (BAC water)
Mixing Volume
2 mL
Half-Life
~12 minutes
Molecular Weight
3,358 Da
Store reconstituted vial refrigerated at 2-8°C. Use within 30 days. Best administered subcutaneously on an empty stomach, ideally 30-60 minutes before bed to align with the body's natural GH pulse during slow-wave sleep.
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FDA Status
Previously FDA approved (1997, as Geref) for pediatric GHD. Brand discontinued 2008. Available in the US via compounding pharmacies on prescription.
Legal Status
Prescription medication in the US (compounded). Research chemical in most other jurisdictions. Prohibited by WADA in competitive sport.
USA
Approved (historical) / compoundedFDA-approved 1997 as Geref; brand discontinued 2008. Legally compounded by 503A pharmacies on prescription.
EU
Not approvedNo active marketing authorization
UK
Not approvedClassified as research chemical
Australia
Not approvedTGA has not authorized
Canada
Not approvedNot authorized for human use
Thorner MO, Reschke J, Chitwood J, Rogol AD, Furlanetto R, Rivier J, Vale W, Blizzard RM
New England Journal of Medicine (1985)
Early clinical work demonstrating that GHRH 1-44 (the parent molecule of Sermorelin) effectively stimulated GH release in GH-deficient children, establishing the rationale for GHRH analog therapy.
View Study →Thorner MO, Rochiccioli P, Colle M, Lanes R, Grunt J, Galazka A, Landy H, Eengrand P, Shah S
Journal of Clinical Endocrinology & Metabolism (1996)
Pivotal pediatric trial supporting Sermorelin's FDA approval, showing significant linear growth acceleration in GH-deficient children dosed nightly with subcutaneous GRF 1-29.
View Study →Walker RF
Clinical Interventions in Aging (2006)
Review of Sermorelin and related GHRH analogs in adult anti-aging applications, discussing dosing strategies, the preservation of physiological GH pulsatility, and safety advantages over exogenous HGH.
View Study →Long-acting growth hormone releasing hormone analog for sustained GH and IGF-1 elevation.
Selective growth hormone secretagogue with minimal side effects.
FDA-approved GHRH analog for HIV-associated lipodystrophy with potent GH-releasing activity.
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