Ipamorelin
Also known as NNC 26-0161
Taken into human trials and did not outperform placebo on its primary endpoint, or development was discontinued. This is stronger evidence than "untested" — it is evidence of absence, not absence of evidence.
What it is
A selective growth hormone secretagogue receptor agonist, developed by Novo Nordisk and later taken into trials for a gastrointestinal indication rather than anything related to body composition.
How it is thought to work
Selective GHS-R1a agonist. Its selectivity — stimulating growth hormone release with little effect on cortisol or prolactin — is what made it useful as a research tool.
What the studies found
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Phase 2 trial did not meet its endpoint
Tested for postoperative ileus, it failed to show benefit on the primary endpoint and development was discontinued. This is a human result, and a negative one.
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Reliable receptor pharmacology
Its selectivity at GHS-R1a is well characterised, which is why it remains a standard comparator in endocrine research.
What the evidence does not show
- The only substantial human trial was negative and development stopped.
- No trials examined body composition, recovery or the uses it is commonly discussed for.
- Growth hormone release in response to a secretagogue is not the same thing as a clinical outcome.
Reported risks and adverse effects
- Short-term human tolerability in the trials that ran appeared acceptable, but the programme was small and discontinued.
- Growth hormone axis stimulation carries theoretical concerns around glucose tolerance and neoplasia.
- No long-term human safety data.
- Prohibited by WADA as a growth hormone secretagogue.
This is a summary of what has been reported in the literature, not a complete safety profile. For anything concerning your own health, speak to a doctor.
Regulatory status
Not approved anywhere. Development discontinued after a failed phase 2 trial.