Comparison
GHRP-6 vs. Sermorelin
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Growth
CAS no.
87616-84-0
86168-78-7
Molecular weight
873.02 g/mol
3358 g/mol
Half-life
0.4 h
0.2 h
Sequence
His-D-Trp-Ala-Trp-D-Phe-Lys-NH2YADAIFTNSYRKVLGQLSARKLLQDIMSRMechanism of action
GHRP-6
GHRP-6 is a high-affinity agonist of the growth-hormone secretagogue receptor 1a (GHSR-1a) — the same receptor later shown to bind the endogenous hormone ghrelin. The identification of GHRP-6 as a pharmacological anchor led to cloning of GHSR in 1996 and the discovery of ghrelin itself in 1999. GHRP-6 stimulates pituitary GH secretion via a pathway independent of GHRH and can be combined synergistically with GHRH. Via GHSR in the hypothalamus it additionally activates NPY/AgRP neurons, producing an orexigenic (appetite-stimulating) effect in animal models.
Sermorelin
Synthetic analogue of the first 29 amino acids of human growth-hormone-releasing hormone (GHRH). Stimulates pulsatile endogenous growth-hormone secretion from the pituitary via the GHRH receptor. Very short plasma half-life — pharmacodynamic effect lasts several hours nevertheless.
Evidence base
Highest evidence
Human trial
Human RCT
Studies
4
5
of which in humans
2
3
Effects recorded
4
3
Open conflicts
1
1
Documented adverse events
2
3
Legal status
Full entries
Frequently asked questions
- What is the difference between GHRP-6 and Sermorelin?
- GHRP-6 is classified as "Growth", while Sermorelin is classified as "Growth". GHRP-6: Synthetic hexapeptide that founded the class of growth-hormone-releasing peptides (GHRPs). Cyril Bowers identified GHRP-6 in the late 1970s as the first orally and parenterally active GH secretagogue with no structural similarity to GHRH. Never approved as a medicine; downstream analogs (GHRP-2, hexarelin, ipamorelin) were pursued clinically. Sermorelin: Synthetic analogue of the first 29 amino acids of human GHRH. Stimulates pulsatile growth-hormone secretion from the pituitary. Formerly FDA-approved as Geref Diagnostic, now withdrawn in many markets — compounding and research use dominate. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, GHRP-6 or Sermorelin?
- The highest available evidence level is "Human trial" for GHRP-6 and "Human RCT" for Sermorelin. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.
- What is the legal status of GHRP-6 and Sermorelin in Germany and the United States?
- Germany: GHRP-6 — Unapproved, Sermorelin — Unapproved. United States: GHRP-6 — Unapproved, Sermorelin — Research only. These are factual summaries with source and review date on the individual pages.