Theoretical · Grade C
Ipamorelin
Ipamorelin Acetate
Score
62 / 100
Half-life
~2 hours
Class
Ghrelin/GHS-R agonist
Status
Investigational
TL;DR
01
A synthetic pentapeptide that stimulates growth-hormone release through the ghrelin receptor — notable for being highly selective, raising GH without the cortisol and prolactin spikes seen with older GH-releasing peptides.
02
That selectivity was demonstrated in animals and cell studies; there are essentially no human efficacy trials for the anti-aging or body-composition uses it is marketed for.
03
Its one notable clinical development program (for post-operative ileus) was discontinued after failing to meet its goals.
04
It is not approved anywhere and is sold as a research chemical or compounded product — purity and dose are not guaranteed.
05
Like all GH secretagogues, it raises IGF-1 and carries the associated glucose and mitogenic cautions, with no long-term human safety data.
Human efficacy RCTs
None
for marketed use
GH selectivity
High
no cortisol/prolactin rise (preclinical)
Clinical program
Discontinued
post-op ileus, did not meet goals
Approval
None
research/compounded only
Long-term safety
Unknown
no human data
Part 01 · How it works
Mechanism.
Ipamorelin mimics ghrelin, the 'hunger hormone,' at the growth-hormone-secretagogue receptor in the pituitary — which triggers a pulse of growth hormone. What made it interesting in the lab is its cleanliness: unlike earlier GH-releasing peptides, it raised GH without also spiking stress hormones like cortisol or prolactin. The catch is that this profile was established in cells and animals; it has never been shown to produce the body-composition benefits it's marketed for in controlled human trials.
A precise key for the growth-hormone release lock — it opens that one door cleanly, without also rattling the stress-hormone doors that older peptides did. But whether opening it changes how a person looks or feels has not been tested in trials.
GHS-R agonism
Agonist at the growth-hormone-secretagogue (ghrelin) receptor, stimulating pituitary GH release.
Selectivity
In rats and swine, released GH comparably to GHRP-6 but without raising ACTH, cortisol, prolactin, FSH, LH, or TSH.
Complementary to GHRH
Acts on a different receptor than GHRH analogs, the rationale for stacking — untested in controlled human studies.
Evidence stage
Preclinical for the mechanism; no human efficacy trials for anti-aging or body composition.
Part 02 · Dosing & administration
How it's taken.
Community-reported · unregulatedValues below reflect commonly reported community protocols for Ipamorelin. These are anecdotal and unregulated — not clinically validated and not a recommendation. Provided for educational purposes only — this is not medical advice and not instructions for self-administration. Consult your healthcare provider before making any health decision.
Standard dose
200-300 mcg
Subcutaneous injection · 1–3x daily on an empty stomach (AM and/or before bed)
Duration
8–12 week cycle (community 5-on/2-off, 8wk-on/8wk-off)
·
A ~300 mcg saturation dose per injection is the common convention; the GH-releasing effect plateaus near this dose.
·
Most selective GHRP — preclinically it released GH without raising ACTH/cortisol, unlike GHRP-2/6 (Raun 1998).
·
No FDA-approved dose; any regimen is from unregulated sources. Take fasted; often paired with a GHRH (CJC no-DAC) if stacking.
Need help with reconstitution?
Use the free peptide calculator for dilution, unit conversion, and injection volume.
Part 03 · Safety
Side effects, rare serious events, who shouldn't.
Common
Injection-site reactions
Anecdotal; no controlled incidence data.
Reported
Headache / flushing
Anecdotal; transient.
Reported
Water retention
A GH-axis effect if GH is meaningfully raised.
Possible
Serious · rare
IGF-1 elevation / mitogenic caution
Raising GH raises IGF-1, which is mitogenic; no human long-term safety data.
Theoretical
Glucose/insulin effects
GH promotes insulin resistance; unquantified for ipamorelin in humans.
Theoretical
Product-quality risk
Research-chemical/compounded supply may not match labeled purity or dose.
Source-dependent
Absolute · do not use
×
Active malignancy or history of cancer
×
Pituitary tumor or hypothalamic disorders
×
Diabetic retinopathy
×
Pregnancy or breastfeeding
×
Children under 18 (unless for diagnosed GH deficiency under specialist care)
×
Known hypersensitivity to ipamorelin or any component
Relative · discuss first
!
Active or prior malignancy — GH/IGF-1 mitogenic caution
!
Pregnancy or breastfeeding — no data
!
Diabetes or impaired glucose tolerance — theoretical worsening
!
Anyone expecting evidence-based benefit — human efficacy has not been shown
Interactions
Insulin
GH secretagogues can increase insulin resistance; may require insulin dose adjustment
Major
Oral hypoglycemics
GH elevation may counteract glucose-lowering effects; monitor blood glucose
Moderate
Corticosteroids
Chronic corticosteroid use blunts GH release and may reduce ipamorelin efficacy
Moderate
Somatostatin analogs (octreotide)
Directly antagonizes GH release stimulated by ipamorelin
Major
Labs to monitor
IGF-1
Baseline, 4 weeks, then every 3 months
Monitor growth hormone axis stimulation
Fasting Glucose & Insulin
Baseline and monthly
GH can impair insulin sensitivity
CMP (Comprehensive Metabolic Panel)
Baseline and every 3 months
Liver and kidney function
CBC with Differential
Baseline and every 3 months
General safety monitoring
Part 04 · Evidence
How strong is the evidence?
62
Grade C
Grade C, downgraded from the library's earlier 'Emerging' rating. Ipamorelin has an elegant, well-documented preclinical mechanism but essentially no human efficacy evidence for its marketed uses, and its one clinical program was discontinued.
Mechanistic plausibility
Clean, selective GH release well documented in cell and animal models.
82
Human evidence
No efficacy RCTs for anti-aging/body composition; the post-op ileus program was discontinued.
40
Safety & tolerability
Preclinically clean, but no long-term human safety data; GH/IGF-1 cautions apply.
60
Durability
No human outcome data on which to judge durability.
50
Independence
Foundational work is independent/academic; the marketed use rests on extrapolation.
60
Part 05 · Research log
Every study we cite.
We list each study with its methodology, funding source, and our quality grade. Flagged studies aren't dismissed — they're tagged so you can weigh them.
01
1998
Eur J Endocrinol Flagged
Ipamorelin, the first selective growth hormone secretagogue
Released GH with potency/efficacy similar to GHRP-6 but, uniquely, without raising ACTH, cortisol, prolactin, or other pituitary hormones — establishing its selectivity.
Preclinical (rat pituitary cells; anesthetized rats; conscious swine) · Foundational pharmacology in animals/cells; does not establish human clinical effect.
PMID 9849822 ↗
Moderate (preclinical)
Evidence against
What didn't work, and where the evidence is thin.
Every publication is incentivized to tell you a peptide works. We catalogue the null results, failed trials, and mechanism limits we found in the same literature — so you can weigh them against the upside, with your provider.
01
Flagship evidence is preclinical; no human efficacy for marketed use
Mechanism limit Eur J Endocrinol · 1998
Ipamorelin's defining data — selective GH release without cortisol/prolactin — come from rat and swine models. There are no controlled human trials demonstrating anti-aging, muscle, or fat-loss benefit.
What this means: A clean mechanism in animals is not evidence of human benefit. Buying ipamorelin for body composition means paying for a hypothesis, not a demonstrated effect.
PMID 9849822 ↗
02
Its clinical development was discontinued
Failed trial Development history · 2026
The most advanced clinical program for ipamorelin (post-operative ileus) did not meet its objectives and development was discontinued — the closest thing to a controlled human test, and it was not a success.
What this means: When ipamorelin was actually put through a controlled clinical program, it did not advance. That absence of a positive human signal should temper expectations.
Part 06 · Cost & access
Where it's available, at what price.
United States
Not approved
No approved product; sold as a research chemical or compounded, typically off-label. No legal consumer medicine.
Grey-market/compounded; unregulated
European Union
Not approved
No approved product.
N/A
United Kingdom
Not approved
No approved product.
N/A
Canada
Not approved
No approved product.
N/A
The Peptide Column takes no affiliate commission from any source. Ipamorelin is not approved as a medicine anywhere; material sold to individuals is research-grade or compounded, unregulated for human use, and its marketed benefits are unproven. We link only to clinician-directed care, never to sellers.
Part 07 · Your appointment
Questions to bring.
01
Is ipamorelin alone sufficient, or should it be combined with CJC-1295?
02
What is the optimal timing for ipamorelin injections relative to meals and sleep?
03
What baseline and follow-up labs (IGF-1, metabolic panel) should I monitor?
04
How long does it take to see results from ipamorelin?
05
Is there a risk of pituitary desensitization with long-term use?
06
How does ipamorelin compare to direct GH replacement for my goals?
References
Every citation, numbered.
Citation list. For our editorial read of each study — including bias flags and quality grades — see the Research log above.
- 01. Ipamorelin, the first selective growth hormone secretagogue · Eur J Endocrinol, 1998 · PMID 9849822 ↗
- 02. Development history. Ipamorelin post-operative ileus program (discontinued) — sponsor disclosures