Sermorelin

GHRH(1-29) analogue - the original pulsatile GH secretagogue. FDA-approved as Geref for paediatric GHD; today compounded as an anti-aging tool.

Formerly FDA-approved (Geref)WADA S2 prohibitedInjectableGH axis

Key facts

Common routesSC

Half-life10–20 minutes

Typical range200–500 mcg

Résumé

Sermorelin is a synthetic analogue of the first 29 amino acids of human GHRH - the catalytically active region of the molecule. Stimulates the pituitary to release GH in its natural pulsatile architecture via GHRH receptor agonism, with somatostatin feedback intact. That's the architecture that avoids the exogenous-GH risk profile: no supraphysiologic IGF-1 load, no forced pituitary suppression.

Geref was the original FDA approval for paediatric GHD. The market withdrawal was economic, not safety-driven - recombinant somatropin became cheaper. Today it's compounded by prescription or grey-market-available; Mod GRF 1-29 (DAC-free or with DAC chain) is the modern sibling with longer half-life.

Notes sur le mécanisme

GHRH receptor agonism

Binds GHRH receptors on pituitary somatotrophs. Stimulates GH synthesis and release in the natural pulsatile architecture - the axis stays feedback-responsive rather than overridden.

Somatostatin feedback intact

Unlike exogenous HGH, the GH released by Sermorelin remains subject to somatostatin inhibition. This safety valve prevents the acromegaly-like effects of chronically supraphysiologic GH exposure.

Physiologic IGF-1 plateau

Result: IGF-1 climbs modestly (+50–150 ng/mL at a 6-week response, depending on baseline) - physiologic range for almost every user. That's the clean risk-to-benefit position for recovery and anti-aging goals.

Dosing patterns

Nightly (default anti-aging)

200–300 mcg SC, 30–60 min before bed, fasted (2+ hours after last meal). Aligns with the natural nocturnal GH peak and deepens it. The lowest-side-effect path in the GH family.

Recovery / body-comp

300–500 mcg daily, or 200 mcg nightly + 200 mcg post-workout on training days. Higher doses saturate receptors without proportional benefit; the dose-response curve flattens past 500 mcg.

Stacked with a GHRP

Sermorelin 100 mcg + Ipamorelin 100 mcg pre-bed is a common stack - synergistic across two different receptors. Practically, Sermorelin's shorter half-life makes it equally good as Mod GRF 1-29 for pre-bed dosing; the main differences are dose precision and sourcing availability.

Aperçu des données

Established clinical efficacy and safety history from paediatric use. Adult anti-aging use is less studied but the mechanism translates; small geriatric trials show expected IGF-1 elevation with modest body-composition changes.

Paediatric clinical data

Walker 1994, Prakash 1999 - studied as Geref for paediatric GHD, with documented growth and IGF-1 outcomes across multi-year treatments.

Adult use

Small trials in older adults show IGF-1 rise and modest improvements in sleep, body composition, and wellness measures. Larger RCTs in healthy adults are absent.

Considérations de sécurité

One of the cleanest safety profiles in the GH family. Acromegaly-like risks are largely avoided by the intact feedback system. Main concerns are injection-site reactions (more common than with other GHRPs due to mild histamine release) and the theoretical tumour-promotion risk shared by all GH-axis compounds.

Common cautions

Injection-site erythema or itching (usually mild, transient)
Facial flush right after injection (vasodilation, clears in minutes)
Theoretical tumour-promotion risk in active cancer history
Watch HbA1c - same as any GH-axis compound