- For
- Growth-hormone support, fat loss and recovery
- Form
- SubQ injection (before bed)
- Dose
- 100-300 mcg, 5 nights / week
- Cycle
- 8-12 weeks
- Safety
- Avoid with cancer or diabetic retinopathy
- Legal
- Research peptide, not FDA-approved
Bottom line: A research peptide that nudges growth hormone with fewer side effects than older ones. Still a GH drug with the same cancer caution. Usually run with CJC-1295.
Safety at a glance
- Status: Not FDA-approved; research peptide.
- Evidence: Animal + early-human; no large outcome trials.
- Do not use if: you have a cancer history - it works on the growth-hormone axis.
- Not medical advice - decide this with a licensed physician.
What it does - plain English
Ipamorelin is a selective GHRP (growth hormone-releasing peptide) that stimulates your pituitary gland to release growth hormone. It works through a different receptor than CJC-1295 - Ipamorelin works on the ghrelin receptor, CJC-1295 on the GHRH receptor - which is why the two are so commonly stacked together: hitting both receptors produces a larger GH pulse than either alone.
Compared to older GHRPs like GHRP-2 and GHRP-6, Ipamorelin is more selective. It raises GH without significantly raising cortisol (the stress hormone), prolactin (a hormone linked to appetite and other effects), or appetite itself. That selectivity is why most modern peptide protocols default to Ipamorelin instead of GHRP-2 or GHRP-6.
It is not a steroid. It is not synthetic growth hormone. It tells your pituitary gland to release more of the growth hormone your body already makes - nothing more.
What people use it for
An A-tier growth-hormone peptide, the gentle one, often paired with CJC-1295. Where people use it:
Status
A-tier within body-composition and GH-supplementation protocols. Pharmacokinetic studies confirm acute GH release without the cortisol and appetite side effects of older GHRPs. The CJC-1295/Ipamorelin combination is the most-prescribed peptide stack in functional medicine and anti-aging telehealth practices.
Long-term safety data in healthy adults is thinner than for FDA-approved drugs. The evidence base here is: strong animal pharmacology, solid short-term human PK data, one Phase 2 clinical trial in surgical patients, and a large volume of clinical experience from compounding physicians - not a typical FDA approval package.
Legal status
Ipamorelin is not FDA-approved for any use in humans. The pharmaceutical version (NN703) was investigated for postoperative ileus - a temporary intestinal slowdown that can follow surgery - but development was halted at Phase 2 in 2007 and was never submitted for approval.
What this means in practice: you cannot buy Ipamorelin over the counter. The common routes are:
- Compounding pharmacy via telehealth prescription - the legal route. A licensed provider writes the script; a compounding pharmacy ships sterile vials. Often co-prescribed with CJC-1295 in a single combination injection. Availability varies by state.
- Research peptide vendors - sold as "for research purposes only, not for human consumption." The peptide may be high-quality, but you have no consumer protection and no regulatory oversight of the supplier.
- Don't - your primary care physician or sports-medicine doc may advise against it pending longer-term human data. That is a defensible position.
Where to source
Always ask for a COA (Certificate of Analysis - the lab report proving the bottle contains what the label says, at the purity stated). No COA, no buy. Period.
The combination compounded prescription - Ipamorelin plus CJC-1295 in one vial - is the cleanest sourcing path. One prescription, one injection, one COA per batch from a licensed pharmacy.
- Compounding pharmacy via telehealth - legal route, prescription required, COA per batch, often combined with CJC-1295 in one bottle. The default recommendation for anyone pursuing this seriously.
- Research peptide vendors - sold for research use only. Specific vendor reviews and price snapshots are in the weekly dispatch when relevant.
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Two studies worth reading
Selective GH release without cortisol bump
Raun, K. et al., European Journal of Endocrinology
The 1998 paper that introduced Ipamorelin and demonstrated its selectivity advantage over earlier GHRPs. Shows strong GH release with no significant effect on cortisol, prolactin, or ACTH across dose ranges. Foundational read for understanding why modern peptide protocols default to Ipamorelin over older secretagogues.
Postoperative ileus trial - where pharmaceutical development stopped
Beck, D. et al., Journal of Gastrointestinal Surgery
Phase 2 trial showing safety and tolerability in 130 postoperative patients. The closest thing to a controlled human safety dataset for the peptide. Development was halted not for safety reasons but for efficacy thresholds in the specific surgical indication - the safety profile held up.
Watch: Huberman on peptides (June 2026)
Huberman's peptide episodes frame ipamorelin as the cleaner-side-effect half of the common growth-hormone stack, but still a GH drug with the same IGF-1 and tumor caution that applies to the whole class, and little reason to use it under age 30.
Source: Huberman Lab - Peptides: The Science, Uses & Safety (Dr. Abud Bakri). See our full decode of what he says about every peptide.
Last reviewed · 2026·06·04 · Status reviewed weekly