Does ipamorelin raise cortisol?
Not in pigs, at doses two hundred times what it takes to release growth hormone — and that is the whole of the evidence. The paper behind the claim is real, from 1998, but it measured swine, and its cortisol sentence compares ipamorelin against another stimulus rather than against an untreated baseline.
In this guide
Where the claim comes from
Raun et al. 1998 is the origin, and its title is a claim in itself: “Ipamorelin, the first selective growth hormone secretagogue”. The selectivity work is one part of a longer pharmacology paper, and the paper says in one sentence where that part was done.
The specificity for GH release was studied in swine.
Swine, then — conscious swine, as the study describes them elsewhere. That is not a disqualification: a pig pituitary is a reasonable place to ask this question, and the later literature repeats the finding rather than overturning it. It is a qualifier, and the value in the matrix carries it in the cell rather than in a footnote, which is why the row reads the way it does in the margin here.
What made the result worth reporting is what the comparators did in the same experiment.
Administration of both GHRP-6 and GHRP-2 resulted in increased plasma levels of ACTH and cortisol.
Two other growth hormone secretagogues put ACTH and cortisol up. The finding is that this one did not do what those did — a contrast, drawn inside one experiment, which is a much better piece of evidence than an isolated null result and also a much narrower claim than “does not raise cortisol” on its own.
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The two halves of it are not equally strong
The recorded value names cortisol and prolactin together. The paper states them in two separate sentences, and the sentences are not the same strength. The prolactin one is flat and covers every compound tested.
None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
Nothing moved, in any of them. The cortisol sentence is built differently, and the difference is its closing clause.
Very surprisingly, ipamorelin did not release ACTH or cortisol in levels significantly different from those observed following GHRH stimulation.
“Not significantly different from those observed following GHRH stimulation” is a comparison, and what it compares to is another stimulus rather than an untreated animal. Read strictly, the sentence says this molecule did not raise ACTH or cortisol more than GHRH did. Whether GHRH itself moved them is a question that sentence does not answer, and no document here answers it either.
The margin the result held over is stated in the next sentence of the same abstract, and it is a wide one.
This lack of effect on ACTH and cortisol plasma levels was evident even at doses more than 200-fold higher than the ED50 for GH release.
What the human literature is quoted as saying instead
A 2026 review, Dominikowski et al. 2026, uses more cautious language for the human evidence: “comparatively minimal activation of other pituitary–adrenal axes in available human studies”.
“Comparatively minimal” does not mean no effect. The animal experiment and the review of human evidence support different conclusions; neither establishes that ipamorelin will leave your cortisol unchanged.
And for the other 4 molecules, nobody here has an answer
The same question has no answer at all for most of the shelf. 1 of the 5 molecules recorded here carries anything on cortisol and prolactin. The other 4 — Sermorelin, Tesamorelin, CJC-1295 (no DAC), CJC-1295 + DAC — read “not recorded”: no study read for this site measured cortisol or prolactin for them either way.
For the other 4 molecules, an effect on cortisol or prolactin is not established in the reviewed sources. An empty comparison field supports neither a claim of an increase nor a claim of no effect.
The 5 attributes on the matrix, and what is not among them
Mechanism · Half-life · Cortisol / prolactin · FDA status · Reported use
None of them is a safety or adverse-event attribute. A single measured endpoint in a single 1998 experiment is not one, and this page must not be read as one — the row is called cortisol and prolactin precisely so that it cannot be.
Molecules with any record on cortisol and prolactin
1 of 5
For the other 4, an effect is not established in the reviewed sources.
Of those, carrying a second document beside the first
1 of 1
Where two documents describe the same property differently, both are printed — Raun et al. 1998 for the measurement and Dominikowski et al. 2026 for the reading of it in people.
Providers listing Ipamorelin
3 of 22
0 published offers list it alone; 6 include it in a combination.
Counted across the five molecules here. The empty part of each bar is the claim. Every document behind a filled cell is on the sources page.
What this page is not
This is one endpoint in one experiment in one species, reported in 1998 and repeated since. It is not a safety profile, it is not a statement about what happens in a person, and it is not a reason to take anything. Nothing here is medical advice, and a question about your own hormones belongs with a licensed clinician; what this page can do is show you the sentences and say which of them the site is resting on.
For published offers, including whether ipamorelin is listed alone or in a combination, see our separate comparison: can you buy ipamorelin on its own? covers the available listings. None of the 6 offers listing ipamorelin offers it alone. What the molecule is, and what one trial recorded in patients, are on what is ipamorelin and ipamorelin side effects.
Sources
The documents behind every figure this page rests on, with the date printed on each one and the day it was read. The quotations are from the abstracts as published, and the page says so wherever it quotes.
4 documents, in the order the figures above use them. The date on each is the one printed on the document.
- Venkova K, Mann W, Nelson R, Greenwood-Van Meerveld B. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus.Document date: 2009-06. PMID 19289567, doi:10.1124/jpet.108.149211.
- Gobburu JV, Agersø H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.Document date: 1999-09. PMID 10496658, doi:10.1023/a:1018955126402.
- Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue.Document date: 1998-11. PMID 9849822, doi:10.1530/eje.0.1390552.
- Dominikowski A, Rękoś Z, Olejarz M, Szczepanek-Parulska E, Domin R, Ruchała M. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration.Document date: 2026-06-18. PMID 42395176, PMC13322892, doi:10.3389/fendo.2026.1822475.