NO. 030 · BASIC · Lv. 65 · HP 110
SERMORELIN
GHRH(1-29) Native Fragment
ALIASES
Sermorelin, GRF(1-29), Geref, GHRH(1-29), GRF 1-29
CLASS
Synthetic peptide · native GHRH(1-29) fragment
FORMULA
C149H246N44O42S
SEQUENCE
Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg
HALF-LIFE
~10-20 minutes
ROUTES
Subcutaneous (research) · Intravenous (diagnostic)
MECHANISM OF ACTION
Synthetic 29-amino-acid fragment representing the native bioactive N-terminus of human GHRH. Engages pituitary GHRH receptors to trigger endogenous GH release. Previously FDA-approved as Geref (pediatric GH deficiency) before withdrawal from US market for commercial reasons.
EVIDENCE GRADES
Geref Phase 3 trials demonstrated GH-stimulating activity in pediatric growth hormone deficiency, supporting 1997 FDA approval.
Adult clinical literature reports modest IGF-1 elevation with chronic dosing.
Limited Western RCT evidence in healthy older adults.
MECHANISM CATEGORIES
RESEARCH CONDITIONS
SAFETY
Side effects
- Injection-site reactions
- Flushing
- Headache
- Mild taste alteration
Known interactions
- Concurrent glucocorticoids may blunt GH response
- Levothyroxine (may need dose adjustment)
Contraindications
- Active malignancy
- Pituitary surgery (pre-existing GH excess)
- Hypersensitivity
REGULATORY STATUS
FDA · Previously FDA-approved as Geref (1997) for pediatric GH deficiency. Voluntarily withdrawn from US market for commercial reasons. Research-use only as of 2026.
WADA · Prohibited at all times under WADA Section S2 (GHRH analog sub-category).
STORAGE
Lyophilized · 2-8 °C, 24 months
Reconstituted · 2-8 °C, 28 days
PEER-REVIEWED EVIDENCE
- Walker RF. Sermorelin: A better approach to management of adult-onset growth hormone insufficiency?. Clin Interv Aging 2006. PMID 18046871. link →
- FDA Center for Drug Evaluation and Research. FDA approval of sermorelin (Geref) for pediatric growth hormone deficiency. FDA approval letter 1997. link →
FAQ · 8 QUESTIONS
▶ What is sermorelin?
Sermorelin is a synthetic 29-amino-acid peptide representing the native bioactive N-terminus of human growth-hormone-releasing hormone (GHRH(1-29)). It engages pituitary GHRH receptors to trigger endogenous GH release.
▶ Sermorelin vs CJC-1295 · what's the difference?
Sermorelin is the unmodified native GHRH(1-29) sequence with a short half-life (~10-20 min) and rapid DPP-IV cleavage. CJC-1295 is the same parent sequence with four stabilizing amino-acid substitutions that resist DPP-IV cleavage (Mod GRF 1-29, No DAC variant). CJC-1295 with DAC adds a covalent albumin-binding linker for ~1-week half-life.
▶ Is sermorelin FDA-approved?
Sermorelin was previously FDA-approved as Geref (1997) for pediatric growth hormone deficiency. It was voluntarily withdrawn from the US market for commercial reasons (not safety) and is research-use only as of 2026.
▶ What is the half-life of sermorelin?
Approximately 10-20 minutes plasma half-life. The unmodified sequence is rapidly cleaved by DPP-IV. Frequent dosing or paired administration with a ghrelin-receptor agonist is used in research to amplify the GH pulse.
▶ Is sermorelin WADA-prohibited?
Yes. Sermorelin is prohibited at all times under WADA Section S2 in the GHRH-analog sub-category.
▶ How does sermorelin work?
Sermorelin binds the GHRH receptor (GHRH-R) on anterior-pituitary somatotrophs and triggers cAMP-mediated release of stored growth hormone. The short half-life produces a pulse closer to the natural pulsatile rhythm than longer-acting analogs.
▶ Sermorelin vs ipamorelin · is one better?
Different mechanisms. Sermorelin acts on the GHRH receptor; ipamorelin acts on the ghrelin / GHS-R1a receptor. The two pathways are complementary; research protocols often pair a GHRH analog (sermorelin or CJC-1295) with a ghrelin-receptor agonist (ipamorelin) to amplify the GH pulse via dual-pathway activation.
▶ Why was Geref withdrawn?
The withdrawal was for commercial reasons rather than safety or efficacy. The pediatric GHD market shifted to recombinant human GH (somatropin), which provides direct GH replacement rather than depending on a functional pituitary.
APPEARS IN STACKS
SIGNATURE MOVES
Native GHRH(1-29) sequence. Short half-life requires frequent dosing.
Endogenous GH release follows natural pulsatile rhythm.
SOURCED FROM PEPPU LABS
Reference compounds documented on this page are available as research-grade material at Peppu Studio · ≥99% purity · per-batch Certificate of Analysis. For laboratory research use only. No human dose is recommended by this wiki.
▶ LAST UPDATED · 2026-05-25