Source comparison
Ipamorelin Mechanism Studies: Key Research Comparisons
Raun et al. (1998) Rat pituitary cells 10–300 nM 8-fold vs baseline No change Confirmed GHS-R1a selectivity; no ACTH pathway activation at any concentration tested Johansen et al. (1999) Swine 0.1–1.0 mg/kg 12–18 ng/mL +4% (not significant) Demonstrated dose-d
This comparison does not assign a generated winner or score.
- Raun et al. (1998)
- Rat pituitary cells
- 10–300 nM
- 8-fold vs baseline
- No change
- Confirmed GHS-R1a selectivity; no ACTH pathway activation at any concentration tested
- Johansen et al. (1999)
- Swine
- 0.1–1.0 mg/kg
- 12–18 ng/mL
- +4% (not significant)
- Demonstrated dose-dependent GH pulses without adrenal stimulation; synergy with GHRH documented
- Svensson et al. (2000)
- Human muscle biopsy
- N/A (receptor assay)
- N/A
- Identified GHS-R1a expression in skeletal muscle; suggested peripheral anabolic signaling beyond pituitary action
- Gobburu et al. (2004)
- Human PK trial
- 0.06–0.9 mcg/kg
- 11.4-fold at 0.9 mcg/kg
- First human demonstration of selective GH release without cortisol or prolactin elevation; half-life = 2 hours
- Sigalos et al. (2017)
- Review / meta-analysis
- Consolidated 15 years of ipamorelin studies; confirmed reproducibility of selectivity profile across species
- Professional Assessment
- These mechanism studies establish that ipamorelin's selectivity is structural and dose-independent. Not a variable outcome. The consistency across rat, swine, and human models makes it one of the most reproducible peptide mechanisms in GH research.