Sermorelin vs Ipamorelin
A GHRH fragment versus a ghrelin-receptor agonist: two different routes to GH release, with very different study records.
Research use only. A summary of published literature for educational reference — not medical advice and not a guide to human use.
The short version
Sermorelin is GHRH(1–29) and has older pediatric growth-deficiency data from when it was marketed as Geref. Ipamorelin acts on the ghrelin receptor instead; its main published human trial, in postoperative ileus, found no significant benefit. Neither has been compared directly with the other.
At a glance
Class
GHRH analogue (GHRH 1–29)
Ghrelin-receptor (GHS-R) agonist
Approval status
Formerly FDA-approved (Geref); discontinued, not for safety or effectiveness reasons per FDA
Investigational; no approved indication
Headline human study
Open-label: height velocity 4.1 → 7.2 cm/year in GH-deficient children (86 analysed)
Phase 2 RCT (114 analysed): no significant benefit for postoperative ileus
Evidence depth
Older pediatric studies; no adult outcome trials
One phase 2 trial plus preclinical pharmacology
Research vial sizes
5 / 10 mg
5 / 10 mg
The details · tap a section to open it
01
How they work
Sermorelin is the first 29 amino acids of growth-hormone-releasing hormone. It binds the GHRH receptor on the pituitary and triggers the body's own GH release.
01
How they work
Sermorelin is the first 29 amino acids of growth-hormone-releasing hormone. It binds the GHRH receptor on the pituitary and triggers the body's own GH release.
Sermorelin is the first 29 amino acids of growth-hormone-releasing hormone. It binds the GHRH receptor on the pituitary and triggers the body's own GH release.
Ipamorelin binds a different receptor — the ghrelin (growth hormone secretagogue) receptor. Early pharmacology work described it as selective for GH release, and it also affects gut motility, which is why it was tested after bowel surgery.
02
What studies measured
In a multicenter open-label study of 110 prepubertal GH-deficient children (86 in the efficacy analysis), mean height velocity rose from 4.1 to 7.2 cm per year over the first year. There was no placebo group.
02
What studies measured
In a multicenter open-label study of 110 prepubertal GH-deficient children (86 in the efficacy analysis), mean height velocity rose from 4.1 to 7.2 cm per year over the first year. There was no placebo group.
In a multicenter open-label study of 110 prepubertal GH-deficient children (86 in the efficacy analysis), mean height velocity rose from 4.1 to 7.2 cm per year over the first year. There was no placebo group.
Ipamorelin's phase 2, double-blind, placebo-controlled trial enrolled 117 bowel-resection patients. Median time to tolerating a solid meal was 25.3 versus 32.6 hours, which was not statistically significant (P=0.15), and secondary efficacy analyses also showed no significant benefit.
03
Reported side effects
The sermorelin pediatric study reported no adverse hormonal or glucose changes and no excessive IGF-I generation.
03
Reported side effects
The sermorelin pediatric study reported no adverse hormonal or glucose changes and no excessive IGF-I generation.
The sermorelin pediatric study reported no adverse hormonal or glucose changes and no excessive IGF-I generation.
In the ipamorelin trial, treatment-emergent adverse events were common in both arms (87.5% versus 94.8% with placebo), as expected after major surgery.
04
Evidence limits
The two compounds were studied in different populations for different outcomes, so their results cannot be compared. Neither record establishes adult body-composition, longevity or performance effects.
04
Evidence limits
The two compounds were studied in different populations for different outcomes, so their results cannot be compared. Neither record establishes adult body-composition, longevity or performance effects.
The two compounds were studied in different populations for different outcomes, so their results cannot be compared. Neither record establishes adult body-composition, longevity or performance effects.
Citations
Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy
3 papers
Citations
Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy
- [1]Multicenter open-label pediatric study1996
Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy
Thorner M, et al. J Clin Endocrinol Metab, 1996.
Read paper ↗ - [2]Phase 2 randomized controlled trial2014
Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients
Beck DE, et al. Int J Colorectal Dis, 2014.
Read paper ↗ - [3]Preclinical pharmacology study1998
Ipamorelin, the first selective growth hormone secretagogue
Raun K, et al. Eur J Endocrinol, 1998.
Read paper ↗
Research use only. A summary of published literature for educational reference — not medical advice and not a guide to human use.
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