Hexarelin and ipamorelin are both GHRPs acting on the ghrelin receptor, but they sit at opposite ends of the "potency vs cleanliness" trade-off. Hexarelin is among the most potent GH releasers but tends to cause desensitization (tolerance) and can affect cortisol/prolactin; ipamorelin is selective and "clean," with minimal off-target effects. Neither is approved.
At a glance
| Hexarelin | Ipamorelin | |
|---|---|---|
| Class | GHRP (ghrelin-receptor agonist) | GHRP (ghrelin-receptor agonist) |
| Potency | Very potent | Moderate, selective |
| Tolerance / desensitization | Notable with continued use | Less pronounced |
| Cortisol / prolactin | Can increase | Minimal effect |
| FDA status | Not approved (research chemical) | Not approved (research chemical) |
| Sport status | Banned (WADA) | Banned (WADA) |
The bottom line
Bottom line: Hexarelin hits hard but comes with downsides — desensitization over time and more hormonal side effects — while ipamorelin trades some raw potency for selectivity and a cleaner profile. Both are unapproved research chemicals with limited human data, and both are prohibited in sport.
Frequently asked questions
Is hexarelin stronger than ipamorelin?
Hexarelin is generally a more potent GH releaser, but it tends to cause desensitization with continued use and can affect cortisol and prolactin. Ipamorelin is less potent but far more selective.
Why is ipamorelin considered 'cleaner'?
Ipamorelin triggers a growth-hormone pulse with minimal effect on appetite, cortisol, and prolactin, whereas hexarelin is more likely to influence those. Neither is FDA-approved.
What is desensitization?
It means the receptor becomes less responsive with repeated stimulation, blunting the effect over time. This is more associated with potent GHRPs like hexarelin. Both peptides are banned in sport.
References
Combined peer-reviewed sources from both peptide guides. Inclusion is not endorsement.
- Tivesten A, Bollano E, Caidahl K, et al. The growth hormone secretagogue hexarelin improves cardiac function in rats after experimental myocardial infarction. Endocrinology. 2000. Peer-reviewed study
- Mao Y, Tokudome T, Kishimoto I. Hexarelin protects cardiomyocytes from ischemia/reperfusion injury through the interleukin-1 signaling pathway. Int Heart J. 2017. Peer-reviewed study
- Mao Y, Tokudome T, Kishimoto I. The cardiovascular action of hexarelin. J Geriatr Cardiol. 2014. Peer-reviewed study
- Guan C, Li C, Shen X, et al. Hexarelin alleviates apoptosis on ischemic acute kidney injury via MDM2/p53 pathway. Eur J Med Res. 2023. Peer-reviewed study
- Jiang B, Wang M, Li X, et al. Hexarelin attenuates abdominal aortic aneurysm formation by inhibiting SMC phenotype switch and inflammasome activation. Microvasc Res. 2022. Peer-reviewed study
- Mosa RM, Zhang Z, Shao R, et al. Implications of ghrelin and hexarelin in diabetes and diabetes-associated heart diseases. Endocrine. 2015. Peer-reviewed study
- Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998. Peer-reviewed study
- Sinha DK, Balasubramanian A, Tatem AJ, et al. Beyond the androgen receptor: growth hormone secretagogues in the management of body composition in hypogonadal males. Transl Androl Urol. 2020. Peer-reviewed study
- Johansen PB, Nowak J, Skjaerbaek C, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999. Peer-reviewed study
- Lu Z, Ngan MP, Liu JYH, et al. The growth hormone secretagogue receptor 1a agonists, anamorelin and ipamorelin, inhibit cisplatin-induced weight loss in ferrets: Anamorelin also exhibits anti-emetic effects via a central mechanism. Physiol Behav. 2024. Peer-reviewed study
- Gouda M, Ganesh CB. The influence of ghrelin agonist ipamorelin acetate on the hypothalamic-pituitary-testicular axis in a cichlid fish, Oreochromis mossambicus. Anim Reprod Sci. 2024. Peer-reviewed study
- Gobburu JV, Agersø H, Jusko WJ, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999. Peer-reviewed study