Sermorelin
Sermorelin Acetate (GHRH 1-29)
Sermorelin is a synthetic analogue of the first 29 amino acids of endogenous GHRH. It was FDA-approved for GH deficiency diagnosis and treatment in children but was voluntarily withdrawn from the US market by the manufacturer in 2008. It remains widely used as a research compound and via compounding pharmacies in some jurisdictions for adult GH deficiency research protocols.
Mechanism of Action
Sermorelin binds GHRH receptors in the anterior pituitary with similar affinity to native GHRH and stimulates GH synthesis and secretion. Its mechanism is essentially identical to endogenous GHRH — it is distinguished primarily by its greater stability (due to amidation) compared to the native 44-amino-acid GHRH.
Sermorelin preserves natural GH pulsatility because it requires intact pituitary function to work — it stimulates the pituitary to produce its own GH rather than delivering exogenous GH. This is considered advantageous for maintaining long-term pituitary axis responsiveness.
Relative to CJC-1295, sermorelin has a shorter half-life and generally produces smaller GH pulses. However, its longer clinical track record (including paediatric data) makes it a well-characterised compound.
Research Evidence
Sermorelin has more human clinical data than any other GHRH analogue due to its period of FDA approval. Adult studies have examined it for age-related GH decline, body composition, and sleep quality.
Sermorelin Administration Improves Body Composition in Adults with Relative GH Deficiency
Six months of sermorelin therapy in adults with age-related GH decline produced significant improvements in lean body mass, fat mass, and IGF-1 levels versus placebo, with no serious adverse events.
Typical Research Protocol
Bedtime dosing synchronises with the natural nocturnal GH surge. Sermorelin alone (without a GHRP) produces smaller GH responses than CJC-1295 + Ipamorelin; it is often preferred for lower-intensity protocols or as a milder entry point.
Safety Profile
Reported Side Effects
- Injection site pain/redness
- Flushing
- Headache
- Dizziness (rare)
- Nausea (rare)
Contraindications
- Active malignancy
- Hypothyroidism (treat first)
- Pregnancy
- Severe cardiovascular disease
Common Research Stacks
Frequently Asked Questions
Is sermorelin still FDA approved?
Sermorelin (Geref) was FDA-approved for paediatric GH deficiency but was voluntarily withdrawn from the US market by its manufacturer in 2008 (due to commercial rather than safety reasons). It is available through compounding pharmacies in some US states under physician supervision and is widely used in anti-aging and functional medicine practice.
How does sermorelin compare to CJC-1295?
Sermorelin is native GHRH(1-29) with amidation; CJC-1295 (without DAC) is a modified version with four amino acid substitutions that extend DPP-IV resistance from ~10 minutes to ~30 minutes. CJC-1295 produces larger, longer-duration GH pulses per injection. Sermorelin is chosen when a more conservative, shorter-acting GHRH stimulus is preferred or when clinical track record is prioritised.
Can sermorelin be used long-term?
Sermorelin protocols of 3–6 months are standard. Some anti-aging practitioners use it for 12+ months with periodic breaks. Because sermorelin stimulates the pituitary to produce its own GH (rather than supplying exogenous GH), it is considered lower-risk for long-term pituitary axis suppression than direct GH administration. Annual IGF-1 monitoring is recommended.
What time of day should sermorelin be injected?
Bedtime dosing is the standard approach — sermorelin's GH-stimulating pulse aligns with and amplifies the natural nocturnal GH surge that occurs during deep sleep (typically 1–3 AM). Dosing 60–90 minutes before sleep in a fasted state (no food 2+ hours prior) maximises GH pulse amplitude.
Does sermorelin require a prescription?
In the US, sermorelin requires a prescription and is typically obtained through compounding pharmacies. It is not available as a brand-name product following its market withdrawal. In some countries it remains available OTC as a research chemical, but prescription-based access through a physician familiar with its use is strongly recommended.
Key Research References
- Walker RF. (2006). Sermorelin: A better approach to management of adult-onset growth hormone insufficiency. Clin Interv Aging.
- Prakash A, Goa KL. (1999). Sermorelin: A review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs.
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