Comparison
Ipamorelin vs. Tesamorelin
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Growth
CAS no.
170851-70-4
901758-09-6
Molecular weight
711.86 g/mol
5135.83 g/mol
Half-life
2 h
0.4 h
Sequence
Aib-His-D-2-Nal-D-Phe-Lys-NH2trans-3-hexenoyl-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-Gln-Gln-Gly-Glu-Ser-Asn-Gln-Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu-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.
Tesamorelin
Tesamorelin is an N-terminally modified 44-amino-acid version of human GHRH(1-44). A 3-hexenoyl modification protects against rapid dipeptidyl-peptidase-IV cleavage. Binding to the pituitary GHRH receptor stimulates endogenous pulsatile growth-hormone secretion and consequently hepatic IGF-1 production.
Evidence base
Highest evidence
Human RCT
Human RCT
Studies
4
4
of which in humans
3
4
Effects recorded
3
3
Open conflicts
1
1
Documented adverse events
1
2
Legal status
Full entries
Frequently asked questions
- What is the difference between Ipamorelin and Tesamorelin?
- Ipamorelin is classified as "Growth", while Tesamorelin 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). Tesamorelin: Stabilised GHRH analog (growth-hormone-releasing hormone). FDA-approved in 2010 as Egrifta for reduction of abdominal lipohypertrophy in HIV-associated lipodystrophy. Not approved for the general population. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, Ipamorelin or Tesamorelin?
- The highest available evidence level is "Human RCT" for Ipamorelin and "Human RCT" for Tesamorelin. 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 Tesamorelin in Germany and the United States?
- Germany: Ipamorelin — Unapproved, Tesamorelin — Unapproved. United States: Ipamorelin — Unapproved, Tesamorelin — Prescription. These are factual summaries with source and review date on the individual pages.