Comparison
Mod GRF (1-29) vs. Sermorelin
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Growth
CAS no.
863288-34-0
86168-78-7
Molecular weight
3367.9 g/mol
3358 g/mol
Half-life
0.5 h
0.2 h
Sequence
Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-NH2YADAIFTNSYRKVLGQLSARKLLQDIMSRMechanism of action
Mod GRF (1-29)
Synthetic analogue of the first 29 amino acids of growth-hormone-releasing hormone (GHRH 1-29). Four amino-acid substitutions (D-Ala at position 2, Gln at 8, Ala at 15, Leu at 27) are intended to slow degradation by dipeptidyl peptidase-IV and increase enzymatic stability relative to native GHRH. Like the native hormone and sermorelin, it binds the GHRH receptor on somatotroph cells of the anterior pituitary; mechanistically this is expected to stimulate endogenous growth-hormone release. Unlike the DAC-conjugated CJC-1295 variant, it lacks albumin binding, so its duration of action remains short.
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
4
3
Effects recorded
3
3
Open conflicts
1
1
Documented adverse events
0
3
Legal status
Full entries
Frequently asked questions
- What is the difference between Mod GRF (1-29) and Sermorelin?
- Mod GRF (1-29) is classified as "Growth", while Sermorelin is classified as "Growth". Mod GRF (1-29): Tetrasubstituted synthetic analogue of GHRH(1-29), traded on the grey market as "CJC-1295 without DAC". Closely related to sermorelin (GHRH 1-29); a short-acting growth-hormone-releasing-hormone analogue often combined with a GHRP/ghrelin mimetic. Not approved as a medicinal product. Direct human trials of this exact analogue are essentially absent; the factual basis relies on related GHRH(1-29) analogues. 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 Formerly FDA-approved as Geref Diagnostic, now withdrawn in many markets — compounding and research use dominate.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, Mod GRF (1-29) or Sermorelin?
- The highest available evidence level is "Human trial" for Mod GRF (1-29) 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 Mod GRF (1-29) and Sermorelin in Germany and the United States?
- Germany: Mod GRF (1-29) — Unapproved, Sermorelin — Unapproved. United States: Mod GRF (1-29) — Research only, Sermorelin — Research only. These are factual summaries with source and review date on the individual pages.