Ipamorelin and sermorelin are both used to encourage the body's own growth-hormone release, but through different doors. Ipamorelin is a GHRP that mimics ghrelin to trigger a GH pulse; sermorelin is a GHRH analog — a fragment of the natural growth-hormone-releasing hormone — that prompts the pituitary along its native pathway. Sermorelin has a notable regulatory history (it was previously an approved diagnostic/therapeutic agent), whereas ipamorelin has only ever been a research compound.
At a glance
| Ipamorelin | Sermorelin | |
|---|---|---|
| Class | GHRP (ghrelin-receptor agonist) | GHRH analog (GHRH 1–29) |
| Mechanism | Triggers a GH pulse via the ghrelin receptor | Stimulates the pituitary via the GHRH receptor |
| Regulatory history | Research chemical only | Formerly FDA-approved (Geref); now compounded/research |
| Selectivity | Minimal cortisol/prolactin/appetite effect | Mimics natural GHRH signaling |
| Duration | Short-acting | Short-acting |
| Sport status | Banned (WADA) | Banned (WADA) |
The bottom line
Bottom line: Ipamorelin (a GHRP) and sermorelin (a GHRH analog) hit different receptors, which is why they're sometimes combined rather than chosen one-over-the-other. Sermorelin carries a longer clinical track record thanks to its former approval, but neither is currently an approved muscle-building or anti-aging therapy, and both are prohibited in sport.
Frequently asked questions
What is the difference between ipamorelin and sermorelin?
Ipamorelin is a GHRP that acts on the ghrelin receptor, while sermorelin is a GHRH analog that acts on the GHRH receptor. Both encourage natural growth-hormone release but through different pathways.
Is sermorelin FDA-approved?
Sermorelin was previously FDA-approved (as Geref) for diagnostic and pediatric growth-hormone uses but was later discontinued; today it is typically supplied through compounding pharmacies. Ipamorelin has only ever been a research chemical.
Can ipamorelin and sermorelin be combined?
Because a GHRP and a GHRH analog act on complementary receptors, they are sometimes used together to increase growth-hormone release. Human evidence for physique or performance benefit is limited, and both are banned in sport.
References
Combined peer-reviewed sources from both peptide guides. Inclusion is not endorsement.
- 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
- Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clin Interv Aging. 2006. Peer-reviewed study
- Kerrigan JR, Martha PM Jr, Blizzard RM, et al. Treatment with GHRH(1-29)NH2 in children with idiopathic short stature induces a sustained increase in growth velocity. J Clin Endocrinol Metab. 1994. Peer-reviewed study
- Prakash A, Goa KL. Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs. 1999. Peer-reviewed study
- Chang Y, Huang R, Zhai Y, et al. A potentially effective drug for patients with recurrent glioma: sermorelin. Ann Transl Med. 2021. Peer-reviewed study