Ipamorelin, the first selective growth hormone secretagogue.

Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH

European journal of endocrinology1 Nov 1998Cited by 59 (Europe PMC)

PMID9849822DOI10.1530/eje.0.1390552PepBankPUB-09849822

Publisher page PubMedAsk about this study

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study23

18 results from studies that gave the peptide. No result from this study comes from people.

01AnimalAnimal study (in vivo)Activity measurement
In pentobarbital anaesthetised rats, ipamorelin released GH with a potency and efficacy comparable to GHRP-6.
In plain wordsIn rats under anaesthesia, ipamorelin released growth hormone with similar strength to GHRP-6.
Peptide
Ipamorelin
Outcome
IncreaseGH release in anaesthetised rats (potency and efficacy)
Study
ratn: not reported in source
pentobarbital anaesthetised rats
Comparator
GHRP-6
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
ED50
80 nmol/kg
anaesthetised rats
Emax
1545 ng GH/ml
anaesthetised rats
Source sentences
Summary
In pentobarbital anaesthetised rats, ipamorelin released GH with a potency and efficacy comparable to GHRP-6 (ED50 = 80+/-42nmol/kg and Emax = 1545+/-250ng GH/ml vs 115+/-36nmol/kg and 1167+/-120ng GH/ml).
Report a problemFND-0984982203
02AnimalAnimal study (in vivo)Activity measurement
In conscious swine, ipamorelin released GH with potency and efficacy very similar to GHRP-6.
In plain wordsIn swine, ipamorelin released growth hormone with very similar strength to GHRP-6.
Peptide
Ipamorelin
Outcome
IncreaseGH release in conscious swine (potency and efficacy)
Study
swinen: not reported in source
conscious swine
Comparator
GHRP-6
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
ED50
2.3 nmol/kg
conscious swine
Emax
65 ng GH/ml plasma
conscious swine
Source sentences
Summary
In conscious swine, ipamorelin released GH with an ED50 = 2.3+/-0.03 nmol/kg and an Emax = 65+/-0.2 ng GH/ml plasma. Again, this was very similar to GHRP-6 (ED50 = 3.9+/-1.4 nmol/kg and Emax = 74+/-7ng GH/ml plasma).
Report a problemFND-0984982204
03AnimalAnimal study (in vivo)Activity measurement
In swine, ipamorelin did not affect plasma FSH levels.
In plain wordsIn swine, ipamorelin did not change blood levels of FSH.
Peptide
Ipamorelin
Outcome
No significant changeFSH plasma level
Study
swinen: not reported in source
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
The specificity for GH release was studied in swine. None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
Report a problemFND-0984982205
04AnimalAnimal study (in vivo)Activity measurement
In swine, ipamorelin did not affect plasma LH levels.
In plain wordsIn swine, ipamorelin did not change blood levels of LH.
Peptide
Ipamorelin
Outcome
No significant changeLH plasma level
Study
swinen: not reported in source
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
The specificity for GH release was studied in swine. None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
Report a problemFND-0984982206
05AnimalAnimal study (in vivo)Activity measurement
In swine, ipamorelin did not affect plasma PRL levels.
In plain wordsIn swine, ipamorelin did not change blood levels of prolactin.
Peptide
Ipamorelin
Outcome
No significant changePRL plasma level
Study
swinen: not reported in source
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
The specificity for GH release was studied in swine. None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
Report a problemFND-0984982207
06AnimalAnimal study (in vivo)Activity measurement
In swine, ipamorelin did not affect plasma TSH levels.
In plain wordsIn swine, ipamorelin did not change blood levels of TSH.
Peptide
Ipamorelin
Outcome
No significant changeTSH plasma level
Study
swinen: not reported in source
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
The specificity for GH release was studied in swine. None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
Report a problemFND-0984982208
07AnimalAnimal study (in vivo)Activity measurement
In swine, ipamorelin did not release ACTH at levels significantly different from GHRH stimulation, even at doses more than 200-fold above the ED50 for GH release.
In plain wordsIn swine, ipamorelin did not raise ACTH more than GHRH stimulation did, even at very high doses.
Peptide
Ipamorelin
Outcome
No significant changeACTH plasma level
Study
swinen: not reported in source
Comparator
GHRH stimulation
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
Very surprisingly, ipamorelin did not release ACTH or cortisol in levels significantly different from those observed following GHRH stimulation. 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.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
Report a problemFND-0984982209
08AnimalAnimal study (in vivo)Activity measurement
In swine, ipamorelin did not release cortisol at levels significantly different from GHRH stimulation, even at doses more than 200-fold above the ED50 for GH release.
In plain wordsIn swine, ipamorelin did not raise cortisol more than GHRH stimulation did, even at very high doses.
Peptide
Ipamorelin
Outcome
No significant changeCortisol plasma level
Study
swinen: not reported in source
Comparator
GHRH stimulation
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
Very surprisingly, ipamorelin did not release ACTH or cortisol in levels significantly different from those observed following GHRH stimulation. 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.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
Report a problemFND-0984982210
09AnimalAnimal study (in vivo)Activity measurement
In pentobarbital-anaesthetised rats, GHRP‑6 released GH with an ED50 of 115 nmol/kg and an Emax of 1167 ng GH/ml.
In plain wordsIn anaesthetised rats, GHRP‑6 caused growth hormone release.
Peptide
GHRP-6
Outcome
IncreaseGH release in anaesthetised rats
Study
ratn: not reported in source
pentobarbital anaesthetised rats
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
ED50
115 nmol/kg
anaesthetised rats
Emax
1167 ng GH/ml
anaesthetised rats
Source sentences
Summary
In pentobarbital anaesthetised rats, ipamorelin released GH with a potency and efficacy comparable to GHRP-6 (ED50 = 80+/-42nmol/kg and Emax = 1545+/-250ng GH/ml vs 115+/-36nmol/kg and 1167+/-120ng GH/ml).
Report a problemFND-0984982212
10AnimalAnimal study (in vivo)Activity measurement
In conscious swine, GHRP‑6 released GH with an ED50 of 3.9 nmol/kg and an Emax of 74 ng GH/ml plasma.
In plain wordsIn conscious swine, GHRP‑6 caused growth hormone release.
Peptide
GHRP-6
Outcome
IncreaseGH release in conscious swine
Study
swinen: not reported in source
conscious swine
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
ED50
3.9 nmol/kg
conscious swine
Emax
74 ng GH/ml plasma
conscious swine
Source sentences
Summary
Again, this was very similar to GHRP-6 (ED50 = 3.9+/-1.4 nmol/kg and Emax = 74+/-7ng GH/ml plasma).
1 context sentence(design, population, supporting numbers)
Summary · context
In conscious swine, ipamorelin released GH with an ED50 = 2.3+/-0.03 nmol/kg and an Emax = 65+/-0.2 ng GH/ml plasma.
Report a problemFND-0984982213
11AnimalAnimal study (in vivo)Safety outcome
In swine, GHRP‑6 administration increased plasma ACTH levels.
In plain wordsIn swine, GHRP‑6 raised blood levels of the stress hormone ACTH.
Peptide
GHRP-6
Outcome
IncreasePlasma ACTH
Study
swinen: not reported in source
swine
Outcome group
Adverse events · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
Administration of both GHRP-6 and GHRP-2 resulted in increased plasma levels of ACTH and cortisol.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
Report a problemFND-0984982214
12AnimalAnimal study (in vivo)Safety outcome
In swine, GHRP‑6 administration increased plasma cortisol levels.
In plain wordsIn swine, GHRP‑6 raised blood levels of the stress hormone cortisol.
Peptide
GHRP-6
Outcome
IncreasePlasma cortisol
Study
swinen: not reported in source
swine
Outcome group
Adverse events · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
Administration of both GHRP-6 and GHRP-2 resulted in increased plasma levels of ACTH and cortisol.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
Report a problemFND-0984982215
13AnimalAnimal study (in vivo)Activity measurement
In swine, GHRP‑2 released GH with an ED50 of 0.6 nmol/kg and an Emax of 56 ng GH/ml plasma.
In plain wordsIn swine, GHRP‑2 caused growth hormone release, with a half-maximal dose of 0.6 nmol/kg.
Peptide
GHRP-2
Outcome
IncreaseGH release in swine (ED50 and Emax)
Study
swinen: not reported in source
Swine
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
ED50
0.6 nmol/kg
GHRP-2 in swine
Emax
56 ng GH/ml plasma
GHRP-2 in swine
Source sentences
Summary
GHRP-2 displayed higher potency but lower efficacy (ED50 = 0.6 nmol/kg and Emax = 56+/-6 ng GH/ml plasma).
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
Report a problemFND-0984982217
14AnimalAnimal study (in vivo)Efficacy outcome
In swine, administration of GHRP‑2 increased plasma ACTH levels.
In plain wordsIn swine, GHRP‑2 raised blood levels of the stress hormone ACTH.
Peptide
GHRP-2
Outcome
IncreasePlasma ACTH
Study
swinen: not reported in source
Swine
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
Administration of both GHRP-6 and GHRP-2 resulted in increased plasma levels of ACTH and cortisol.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
Report a problemFND-0984982218
15AnimalAnimal study (in vivo)Efficacy outcome
In swine, administration of GHRP‑2 increased plasma cortisol levels.
In plain wordsIn swine, GHRP‑2 raised blood levels of the stress hormone cortisol.
Peptide
GHRP-2
Outcome
IncreasePlasma cortisol
Study
swinen: not reported in source
Swine
Outcome group
Pituitary hormones · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
Administration of both GHRP-6 and GHRP-2 resulted in increased plasma levels of ACTH and cortisol.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
Report a problemFND-0984982219
16LabIn vitro (cells)Activity measurement
In primary rat pituitary cells, ipamorelin released GH with a potency and efficacy similar to GHRP-6.
In plain wordsIn cells, ipamorelin made rat pituitary cells release growth hormone, with similar strength to GHRP-6.
Peptide
Ipamorelin
Outcome
IncreaseGH release from primary rat pituitary cells (potency and efficacy)
Study
ratn: not reported in source
primary pituitary cells
Comparator
GHRP-6
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
EC50
1.3 nmol/l
rat pituitary cells
Emax
85%
rat pituitary cells
Source sentences
Summary
In vitro, ipamorelin released GH from primary rat pituitary cells with a potency and efficacy similar to GHRP-6 (ECs) = 1.3+/-0.4nmol/l and Emax = 85+/-5% vs 2.2+/-0.3nmol/l and 100%).
Report a problemFND-0984982201
17LabIn vitro (cells)Activity measurement
In primary rat pituitary cells, GHRP‑6 released GH with an EC50 of 2.2 nmol/l and an Emax of 100%.
In plain wordsIn rat pituitary cells in lab tests, GHRP‑6 caused growth hormone release at a low concentration.
Peptide
GHRP-6
Outcome
IncreaseGH release potency and efficacy in pituitary cells
Study
ratn: not reported in source
primary rat pituitary cells
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Studied dose
Dose not stated
Measurements
EC50
2.2 nmol/l
rat pituitary cells
Emax
100%
rat pituitary cells
Source sentences
Summary
In vitro, ipamorelin released GH from primary rat pituitary cells with a potency and efficacy similar to GHRP-6 (ECs) = 1.3+/-0.4nmol/l and Emax = 85+/-5% vs 2.2+/-0.3nmol/l and 100%).
Report a problemFND-0984982211
18LabOther designMechanism
Pharmacological profiling with GHRP and GHRH antagonists showed that ipamorelin, like GHRP-6, stimulates GH release via a GHRP-like receptor.
In plain wordsIn lab tests, ipamorelin, like GHRP-6, released growth hormone through a GHRP-like receptor.
Peptide
Ipamorelin
Outcome
Not applicableReceptor pathway of GH release
Study
n: not reported in source
Comparator
GHRP-6
Outcome group
Receptor activity and mechanism · Endocrine and hormones
Studied dose
Dose not stated
Source sentences
Summary
A pharmacological profiling using GHRP and growth hormone-releasing hormone (GHRH) antagonists clearly demonstrated that ipamorelin, like GHRP-6, stimulates GH release via a GHRP-like receptor.
Report a problemFND-0984982202

Studies that did not test the peptide alone5

In this study, the peptide was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking the peptide.

19AnimalNot a test of GHRP-6 aloneAnimal study (in vivo)Safety outcome
In swine, none of the GH secretagogues tested, pooled, changed plasma FSH, LH, PRL or TSH levels.
In plain wordsIn swine, none of the growth hormone releasing compounds tested changed blood levels of four other pituitary hormones.
Peptide
GHRP-6
Outcome
No significant changePlasma FSH, LH, PRL and TSH
Study
swinen: not reported in source
swine
Outcome group
Sex hormones and fertility · Endocrine and hormones
Source sentences
Summary
None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-0984982216
20AnimalNot a test of GHRP-2 aloneAnimal study (in vivo)Efficacy outcome
In swine, none of the GH secretagogues tested, a group that includes GHRP‑2, affected plasma FSH.
In plain wordsIn swine, none of the tested growth hormone releasing compounds, GHRP‑2 among them, changed blood FSH.
Peptide
GHRP-2
Outcome
No significant changePlasma FSH
Study
swinen: not reported in source
Swine
Outcome group
Sex hormones and fertility · Endocrine and hormones
Source sentences
Summary
None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
In this study, GHRP-2 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-2.
Report a problemFND-0984982220
21AnimalNot a test of GHRP-2 aloneAnimal study (in vivo)Efficacy outcome
In swine, none of the GH secretagogues tested, a group that includes GHRP‑2, affected plasma LH.
In plain wordsIn swine, none of the tested growth hormone releasing compounds, GHRP‑2 among them, changed blood LH.
Peptide
GHRP-2
Outcome
No significant changePlasma LH
Study
swinen: not reported in source
Swine
Outcome group
Sex hormones and fertility · Endocrine and hormones
Source sentences
Summary
None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
In this study, GHRP-2 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-2.
Report a problemFND-0984982221
22AnimalNot a test of GHRP-2 aloneAnimal study (in vivo)Efficacy outcome
In swine, none of the GH secretagogues tested, a group that includes GHRP‑2, affected plasma PRL.
In plain wordsIn swine, none of the tested growth hormone releasing compounds, GHRP‑2 among them, changed blood prolactin.
Peptide
GHRP-2
Outcome
No significant changePlasma PRL
Study
swinen: not reported in source
Swine
Outcome group
Pituitary hormones · Endocrine and hormones
Source sentences
Summary
None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
In this study, GHRP-2 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-2.
Report a problemFND-0984982222
23AnimalNot a test of GHRP-2 aloneAnimal study (in vivo)Efficacy outcome
In swine, none of the GH secretagogues tested, a group that includes GHRP‑2, affected plasma TSH.
In plain wordsIn swine, none of the tested growth hormone releasing compounds, GHRP‑2 among them, changed blood TSH.
Peptide
GHRP-2
Outcome
No significant changePlasma TSH
Study
swinen: not reported in source
Swine
Outcome group
Pituitary hormones · Endocrine and hormones
Source sentences
Summary
None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels.
1 context sentence(design, population, supporting numbers)
Summary · context
The specificity for GH release was studied in swine.
In this study, GHRP-2 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-2.
Report a problemFND-0984982223

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Versions 22 to 45Current
28 Oct 2026, 02:02 UTC
The same notice was added 24 times, first on 13 Oct 2026, 21:43 UTC. The status did not change between them.
Study results updated
Version 21
13 Oct 2026, 16:31 UTC
Study data updated · source update from Europe PMC
Versions 3 to 20
13 Oct 2026, 14:22 UTC
The same notice was added 18 times, first on 9 Oct 2026, 18:17 UTC. The status did not change between them.
Study results updated
Version 2
9 Oct 2026, 03:13 UTC
Study data updated · source update from Europe PMC
Version 1
9 Oct 2026, 03:13 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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