Ipamorelin vs Tesamorelin
Ipamorelin (Growth-hormone secretagogue (GHRP) / ghrelin receptor agonist) and Tesamorelin (GHRH analog (stabilized long-acting GHRH(1-44) analog)) are documented as co-studied in the PeptiDex library. This page puts the two entries side by side on class, molecular weight, half-life, origin, mechanism and studied research areas — every value taken from the entry it belongs to.
Why these two are co-studied
Cross-referenced for research context — not a usage or combination recommendation.
At a glance
| Attribute | Ipamorelin | Tesamorelin |
|---|---|---|
| Compound class | Growth-hormone secretagogue (GHRP) / ghrelin receptor agonist | GHRH analog (stabilized long-acting GHRH(1-44) analog) |
| Research category | Growth & GH-Axis | Growth & GH-Axis |
| Length (amino acids) | 5 amino acids | 44 amino acids |
| Molecular weight | 711.9 g/mol | Approximately 5136 g/mol |
| Half-life | ~2 hours (reported approximately 120 minutes) | Short in circulation (reported approximately 26-38 minutes) despite chronic dosing effects |
| Origin | Ipamorelin is a synthetic pentapeptide developed in the 1990s (originally by Novo Nordisk) as a selective growth-hormone secretagogue. It was designed to stimulate GH release with minimal off-target hormonal effects. | Tesamorelin is a synthetic analog of human growth-hormone-releasing hormone (GHRH 1-44) with an N-terminal trans-3-hexenoyl modification that improves stability. It is marketed as Egrifta. |
“Not documented” means the PeptiDex entry records no value for that field. Nothing on this page is estimated, and no figure is carried over from one compound to the other.
How Ipamorelin works
Ipamorelin is an agonist of the growth-hormone secretagogue receptor (GHS-R1a, the ghrelin receptor), mimicking ghrelin to stimulate GH release from the anterior pituitary. It acts on the pituitary and hypothalamus to promote a pulsatile release of growth hormone. Unlike some other GHRPs, it is reported to be highly selective, releasing GH without significantly stimulating ACTH, cortisol, or prolactin at effective doses.
How Tesamorelin works
Tesamorelin is an agonist of the GHRH receptor on anterior-pituitary somatotrophs, stimulating endogenous GH secretion and raising IGF-1. The N-terminal hexenoyl group protects it from rapid DPP-4 degradation, improving stability relative to native GHRH. By acting upstream, it stimulates physiologic GH release subject to normal feedback.
Mechanistic descriptions reflect published research-literature understanding and are quoted from each compound's own entry. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
Where each one appears in the literature
The research contexts each entry documents. Listing a research area is not a claim of efficacy or a therapeutic indication, and the two lists are not scored against each other.
Ipamorelin
Tesamorelin
What sets each apart
Ipamorelin
Among GHRPs, ipamorelin is noted for its selectivity — stimulating GH release without the appetite, cortisol, and prolactin elevations associated with GHRP-6 and hexarelin.
Tesamorelin
Tesamorelin is a stabilized GHRH(1-44) analog and, uniquely in this set, an FDA-approved medicine, distinguishing it from research-only GHRH analogs like sermorelin and CJC-1295.
Frequently asked questions
What is ipamorelin and what class of compound is it?
Ipamorelin is a synthetic pentapeptide growth hormone secretagogue (a ghrelin/GHS-R1a receptor agonist). It is studied as one of the most selective GHRPs, stimulating pulsatile GH release from the anterior pituitary with minimal effect on cortisol, prolactin, or ACTH in research models.
How does ipamorelin differ from GHRP-2 and GHRP-6?
All three activate the ghrelin receptor (GHS-R1a), but ipamorelin is the most selective: in the research literature it drives GH release without the appetite stimulation seen with GHRP-6 or the cortisol/prolactin elevation associated with GHRP-2. This selectivity is why it is frequently used as a reference GHRP in study design.
Why is ipamorelin commonly studied alongside a GHRH analog like CJC-1295?
Ipamorelin (a GHS-R agonist) and a GHRH analog such as CJC-1295 or sermorelin act on two different receptor pathways. Research protocols pair them because combined GHRH + GHRP stimulation produces a synergistic, amplified GH pulse greater than either compound alone.
What is tesamorelin?
Tesamorelin is a synthetic stabilized analog of the full 44-amino-acid human growth hormone-releasing hormone (GHRH). A trans-3-hexenoic acid group is attached to the N-terminus to resist enzymatic degradation, and it acts on the GHRH receptor to stimulate endogenous GH secretion.
Is tesamorelin an FDA-approved drug?
Yes. Tesamorelin (brand name Egrifta) is FDA-approved for the reduction of excess abdominal fat in HIV-infected patients with lipodystrophy. It is one of the few GHRH analogs to reach full FDA approval; an updated F8/WR formulation was approved in 2025.
How does tesamorelin differ from sermorelin and CJC-1295?
Sermorelin and CJC-1295 are based on the shorter GHRH(1-29) fragment, whereas tesamorelin is a stabilized analog of the full 44-amino-acid GHRH. Its N-terminal modification gives it greater stability than sermorelin while remaining a short-acting daily-dosed GHRH analog.
Answers are the ones published on each compound's own PeptiDex entry. They are educational summaries of research-literature context and are not medical advice.