Ipamorelin
Compound snapshot
Class
Research peptide
FDA approved
No
Clinical development
Phase 2
Last reviewed
September 2026
Research areas
Growth hormone axis / Body composition / Recovery
Regulatory status
Research use only — not approved
Internet attention
Moderate
Registry query
Ipamorelin
A selective growth hormone secretagogue — a pentapeptide that mimics ghrelin at the GHS-R1a receptor without ghrelin's other effects.
Reality check — what we actually know
Supported by human evidence
- No adequately powered randomised human trials establish the outcomes this compound is marketed for.
Animal research only
- Restores a more youthful pulsatile GH pattern rather than replacing GH directly
- Downstream IGF-1 rise supporting muscle protein synthesis and connective-tissue repair
- Studied for improved sleep depth, which is when natural GH release peaks
Mechanistically plausible
- Triggers a pulse of the body's own growth hormone from the pituitary. Unlike older secretagogues it does not meaningfully raise cortisol, prolactin or ACTH, which is why it is the most-discussed of the class.
Common internet claims
- Online discussion frequently presents Ipamorelin as a proven treatment rather than a research compound.
Not established
- Human efficacy for the outcomes commonly claimed
- Optimal route, quantity and duration in humans
- Long-term human safety
Evidence distribution
Each band is a live PubMed search for Ipamorelin, filtered to that kind of study. Top is the strongest evidence; the base is reasoning, not proof. A band with no records means that kind of study has not been published for this compound yet.
Mechanism and reported findings
Triggers a pulse of the body's own growth hormone from the pituitary. Unlike older secretagogues it does not meaningfully raise cortisol, prolactin or ACTH, which is why it is the most-discussed of the class.
- Restores a more youthful pulsatile GH pattern rather than replacing GH directly
- Downstream IGF-1 rise supporting muscle protein synthesis and connective-tissue repair
- Studied for improved sleep depth, which is when natural GH release peaks
- Bone mineral density support in animal models
- Less appetite stimulation than ghrelin-like peptides such as GHRP-6
Strength of the evidence: Phase 2 human trials were run for post-operative ileus and did not proceed to approval. No approved human indication anywhere.
Safety and known cautions
Raising GH/IGF-1 is a theoretical growth signal for existing tumours. Can cause water retention, joint ache and insulin resistance. WADA-prohibited.
Evidence at a glance
No single score, on purpose. The line beside each bar shows how much reported outcomes vary between studies.
Development stage
- Discovery
- Preclinical
- Phase 1
- Phase 2Current
- Phase 3
- Regulatory review
- Approved