Comparison
Ipamorelin vs. Mod GRF (1-29)
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Growth
CAS no.
170851-70-4
863288-34-0
Molecular weight
711.86 g/mol
3367.9 g/mol
Half-life
2 h
0.5 h
Sequence
Aib-His-D-2-Nal-D-Phe-Lys-NH2Tyr-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-NH2Mechanism of action
Ipamorelin
Ipamorelin is a selective agonist at the GH secretagogue receptor (GHSR-1a). Compared to GHRP-2 and GHRP-6 its selectivity for the growth-hormone axis is higher; ACTH, cortisol and prolactin are not significantly stimulated in clinical studies. This selectivity was the main reason for its development over older GHRPs.
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.
Evidence base
Highest evidence
Human RCT
Human trial
Studies
4
4
of which in humans
3
4
Effects recorded
3
3
Open conflicts
1
1
Documented adverse events
1
0
Legal status
Full entries
Frequently asked questions
- What is the difference between Ipamorelin and Mod GRF (1-29)?
- Ipamorelin is classified as "Growth", while Mod GRF (1-29) is classified as "Growth". Ipamorelin: Synthetic pentapeptide and selective growth-hormone secretagogue. Developed at Novo Nordisk in the 1990s as a pentapeptide GHRP successor; clinical development was discontinued after phase 2 (post-operative ileus). 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. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, Ipamorelin or Mod GRF (1-29)?
- The highest available evidence level is "Human RCT" for Ipamorelin and "Human trial" for Mod GRF (1-29). 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 Ipamorelin and Mod GRF (1-29) in Germany and the United States?
- Germany: Ipamorelin — Unapproved, Mod GRF (1-29) — Unapproved. United States: Ipamorelin — Unapproved, Mod GRF (1-29) — Research only. These are factual summaries with source and review date on the individual pages.