Ipamorelin
NNC 26-0161
A short pentapeptide that stimulates the pituitary to release growth hormone. Its reputation rests on selectivity: it raises GH without meaningfully raising cortisol, prolactin or appetite.
- Category
- Longevity
- Half-life
- Approximately 2 hours
- Cycle length
- 8–16 weeks, often with a washout period
- Level
- beginner
Overview
Ipamorelin was developed as a selective growth-hormone secretagogue, meaning it prompts the pituitary to release the body's own growth hormone rather than introducing GH itself. That distinction matters: endogenous release is pulsatile, and the body's normal feedback mechanisms remain intact. It is often the first compound people encounter in the GH-axis part of biohacking, and it remains one of the best-characterised.
How it works
Ipamorelin is a ghrelin-receptor agonist. It binds the GHS-R1a receptor in the pituitary and hypothalamus, triggering a GH pulse. Because it is highly selective for that receptor, it avoids the off-target activity that causes cortisol and prolactin elevation with older secretagogues such as GHRP-6.
Reported benefits
- Increased pulsatile growth-hormone release
- Improved sleep quality reported consistently
- Recovery and joint comfort reports
- No significant appetite increase, unlike GHRP-6
Reported benefits describe what the published literature and user reports suggest — not a promise of outcome for any individual.
Dosing reference
Commonly described at 200–300 mcg per administration, typically two to three times daily, with dosing before sleep being the most frequent pattern. Subcutaneous injection is standard.
Timing matters in practice: doses are usually placed away from food, because the GH pulse is blunted by circulating glucose and insulin. Most protocols also pause for two to four weeks every few months.
Community-reported: 200–300 mcg by subcutaneous injection once to three times daily, most often 20–30 minutes before sleep and before training, frequently paired with 100–200 mcg of CJC-1295 (no DAC). Higher nightly amounts are described as causing water retention and lethargy.
These figures are what people report using in public communities. They have not been studied, verified or checked against certificates of analysis, and they are not a recommendation, a prescription or a target to aim for.
Where the reported amounts come from
Amounts are reproduced for education only. Doses from trials cannot be assumed to suit anyone else, and community-reported amounts are frequently wrong. Self-administering unapproved compounds carries serious risk.
The research picture
Human studies are small but real: controlled work has demonstrated dose-dependent GH release with minimal effect on cortisol, prolactin and appetite — the finding that earned ipamorelin its reputation for selectivity. What has not been demonstrated in robust human trials is that this translates into meaningful body-composition or longevity outcomes. The hormone effect is well documented; the downstream outcomes are assumed.
Primary sources
Preclinical & non-clinical data
Preclinical work characterises ipamorelin as a selective ghrelin-receptor agonist that triggers growth-hormone release with minimal effect on cortisol, prolactin or appetite — that selectivity is why it is the most discussed secretagogue. Human data is limited to small studies measuring the hormone pulse, not outcomes like strength, body composition or sleep quality.
Non-clinical data comes from cells and animals unless stated otherwise. It answers whether a compound is worth studying in people — not whether it is safe or effective in them.
What users report
This is one of the most reported compounds in the fitness and longevity communities. The dominant account is deeper, more continuous sleep within the first weeks of pre-sleep dosing, followed by faster recovery and, over several months, small changes in body composition — usually stacked with a GHRH analogue. Just as informative are the caveats users themselves keep repeating: that results take months, that diet and training decide the outcome, that nobody measured their own growth hormone, and that stopping returns everything to baseline. Water retention and occasional headaches appear in reports.
Where these reports come from
These are unverified personal accounts collected from public sources. They are not evidence of effectiveness or safety, they have not been independently checked, and they are not a recommendation to use anything described.
Possible side effects
- Transient headache
- Injection-site irritation
- Water retention reported anecdotally
- Tingling or numbness reported with sustained use
- Increased hunger when used alongside GHRP-class compounds
Safety notes
Because it raises growth hormone and IGF-1, it is unsuitable for anyone with active malignancy or proliferative retinopathy. It can worsen insulin resistance in susceptible individuals — monitor fasting glucose. Do not use with untreated pituitary disease.
Stacking
Most often combined with a GHRH analogue such as CJC-1295, on the reasoning that the two act on different receptors and produce a larger combined pulse than either alone. Also seen in recovery stacks with BPC-157.
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