Sermorelin Dosing Protocol

Sermorelin acetate (GRF 1-29) is a synthetic 29-amino acid peptide analogue of human growth hormone-releasing hormone (GHRH) and is one of the most widely used GHRH-based peptides for growth hormone optimization research. Sermorelin represents the shortest fully functional fragment of endogenous GHRH (which consists of 44 amino acids), retaining equivalent biological potency at the GHRH receptor while offering a more practical molecular profile for clinical use.

Structurally, Sermorelin corresponds to the amino-terminal segment (residues 1-29) of naturally occurring human GHRH. The peptide has the molecular formula C149H246N44O42S with a molecular weight of 3,358 daltons. The C-terminus is amidated (NH2), which contributes to receptor-binding stability. Unlike modified analogues such as tesamorelin, sermorelin does not contain structural modifications to resist enzymatic degradation, which accounts for its short plasma half-life of approximately 11-12 minutes following subcutaneous administration.

Sermorelin was originally approved by the FDA in 1990 as a diagnostic agent for GH deficiency, and subsequently in 1997 for the treatment of idiopathic growth hormone deficiency in children, marketed under the brand name Geref by Serono Laboratories. The manufacturer voluntarily discontinued production in 2008 due to manufacturing process difficulties, not safety concerns.

Sermorelin remains available through compounding pharmacies for off-label prescribing and as a research peptide, and has gained traction in anti-aging and longevity medicine for its ability to stimulate endogenous GH production through natural pituitary pathways rather than direct exogenous GH administration.

This compound is not currently FDA-approved for any indication. All information on this page is for educational and research reference purposes only.

Clinical-era data characterize sermorelin as generally well tolerated, with injection-site reactions as the most common adverse event and low discontinuation burden in FDA-era programs.

Injection-site reactions: Most frequent adverse event, roughly 1 in 6 patients (about 17%) in trial context, typically mild and transient. In historical datasets, only a small subset discontinued specifically for injection-site reactions.

Less common effects (<1%): Headache, facial flushing, dysphagia, dizziness, hyperactivity, somnolence, dysgeusia, and urticaria were each reported at low incidence and were generally self-limited.

Antibody development: Anti-GRF antibodies were reported in a high proportion of participants (around 70% in some datasets) but were generally of limited clinical significance for observed outcomes.

Hypothyroidism monitoring: Hypothyroidism incidence around 6.5% was reported in trial programs, and historical prescribing guidance included baseline and follow-up thyroid monitoring because untreated hypothyroidism may blunt GH response.

Abuse/dependence profile: Clinical pharmacology literature indicates low abuse and dependence potential; no such signals were highlighted in trial programs.

Overall tolerability: Discontinuation due to adverse events was low in FDA-era programs, with feedback-limited endogenous GH release considered a favorable safety characteristic versus exogenous GH.

All three compounds target the GHRH receptor but differ substantially in pharmacokinetics, approval history, and modern evidence depth.

Sermorelin requires nightly dosing due to short half-life but retains extensive historical clinical context and feedback-limited pulse behavior.

Tesamorelin has stronger modern controlled evidence for visceral-fat outcomes, while CJC-1295 (DAC) emphasizes dosing convenience. For related guidance, compare with tesamorelin and CJC-1295 protocol pages before selecting a protocol model.

See the Tesamorelin protocol and CJC-1295 protocol for compound-specific guides.