Quick summary
Sermorelin is the shortest active GHRH fragment (amino acids 1-29), formerly FDA-approved as Geref. It stimulates pulsatile GH release while preserving the natural feedback loop, making it one of the most studied anti-aging peptides.
Overview
Sermorelin is the shortest fully functional fragment of growth hormone-releasing hormone (GHRH), consisting of the first 29 amino acids. It was FDA-approved in 1997 as Geref for diagnosing and treating growth hormone deficiency in children, though it was discontinued commercially in 2008. It remains one of the most well-studied GH-releasing peptides with established clinical safety data.
Mechanism of action
Sermorelin binds to the GHRH receptor on anterior pituitary somatotroph cells, stimulating the synthesis and pulsatile release of endogenous growth hormone. Unlike exogenous GH administration, sermorelin preserves the hypothalamic-pituitary feedback loop, maintaining physiological GH regulation. It stimulates all five somatotroph cell subtypes.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| anti-aging / GH optimization | subcutaneous | 200–500 mcg | daily at bedtime | Inject before sleep to synergize with natural nocturnal GH pulse. 3-6 month cycles recommended. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Extensive clinical trial data from FDA approval process. Studies demonstrate significant increases in GH and IGF-1 levels, improved body composition (reduced fat mass, increased lean mass), improved sleep quality (increased slow-wave sleep), and improved skin elasticity. The Rudman 1990 NEJM study on GH in aging and subsequent sermorelin studies established the foundation for anti-aging peptide use.[1][2][3][4][5]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Sermorelin for synergistic effects.
Legal status
Previously FDA-approved (Geref, 1997). Discontinued commercially in 2008 but still available through compounding pharmacies. Under reclassification review.
Sourcing & access
Reclassification in progress
Sermorelin is one of 14 peptides under FDA reclassification review. Access may be restored through licensed compounding pharmacies if reclassification is formalized. Check our regulatory timeline for the latest status.
Frequently asked questions
Sermorelin is a growth hormone-releasing hormone (GHRH) analogue used to stimulate the pituitary gland to produce natural growth hormone. It received FDA approval in 1997 under the brand name Geref for pediatric growth hormone deficiency. Off-label uses include adult anti-aging, body composition improvement, sleep quality enhancement, and general GH optimization through compounding pharmacies.
Sermorelin stimulates the pituitary to release GH in a pulsatile, physiologically regulated pattern, preserving the hypothalamic-pituitary-thyroid (HPT) feedback loop. This prevents supraphysiological GH or IGF-1 levels. Exogenous synthetic HGH bypasses this feedback entirely, suppresses natural GH secretion over time, and carries higher risks of side effects including insulin resistance and carpal tunnel syndrome.
Sermorelin was FDA-approved in 1997 but its branded pharmaceutical form (Geref) was voluntarily discontinued in 2008. It is currently under regulatory review for reclassification. Compounding pharmacies can still prepare sermorelin for patients with a valid prescription. Its legal status in some compounding contexts has been uncertain since 2023 FDA guidance updates.
The most common research and off-label protocol uses 200 to 500 micrograms administered subcutaneously at bedtime, which aligns with the natural nocturnal GH pulse. Cycles typically run 3 to 6 months before reassessment. Bedtime dosing is preferred because it amplifies the largest physiological GH pulse that naturally occurs during slow-wave sleep.
The most commonly reported side effects are injection site reactions including redness, pain, and swelling. Systemic effects may include facial flushing, headache, dizziness, and transient sleepiness, typically occurring shortly after injection. These effects are generally mild and dose-dependent. Serious adverse events are uncommon but may include fluid retention or hypersensitivity reactions in rare cases.
Research references
- Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and womenPubMed
- Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?PubMed
- Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy. Geref International Study GroupPubMed
- Growth Hormone–Releasing Hormone Effects on Brain γ-Aminobutyric Acid Levels in Mild Cognitive Impairment and Healthy AgingPubMed
- Effects of growth hormone-releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trialPubMed
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