Ipamorelin
IPA
Growth Hormone
CAS
170851-70-4
Molecular Weight
711
Da
Animal Only
A selective synthetic peptide that stimulates growth hormone release from the pituitary gland without significantly affecting cortisol or prolactin. One of the most popular peptides in longevity and performance protocols due to its clean hormonal profile. Has reached human clinical trials. Often combined with CJC-1295 for amplified effect.
Injectable
Intranasal Suitable
Yes
Research Compound
Community Signal
Community signal is generally positive but methodologically murky. Ipamorelin is almost universally discussed in combination with CJC-1295 rather than as a standalone compound, making isolated attribution nearly impossible. The CJC/Ipa stack is one of the most commonly referenced peptide combinations in biohacking forums. Sleep quality, recovery, and mild body composition changes are the most frequently cited benefits. Side effect reports are notably rare compared to other GH secretagogues, which the community attributes to its GH-specific mechanism without cortisol or prolactin elevation. Dosing timing debates, pre-bed vs pre-workout, are a recurring community discussion.
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What It Is
Ipamorelin is a synthetic pentapeptide — a chain of five amino acids — and a selective growth hormone secretagogue. Unlike other peptides in its class, ipamorelin stimulates growth hormone release with high selectivity, meaning it triggers GH release without significantly affecting other hormones like cortisol or prolactin. It was originally developed by Novo Nordisk in the 1990s and reached Phase II clinical trials before development was discontinued for commercial reasons unrelated to safety.
Mechanism of Action
Ipamorelin works by mimicking ghrelin and binding to the ghrelin receptor (GHS-R1a) in the pituitary gland, stimulating a pulse of growth hormone release. What distinguishes it from other growth hormone secretagogues like GHRP-2 or GHRP-6 is its selectivity — it produces a clean GH pulse without the appetite stimulation, cortisol spike, or prolactin elevation associated with less selective peptides. It is often combined with a GHRH (Growth Hormone Releasing Hormone) analog like CJC-1295 to amplify and extend the GH pulse.
Use Cases
Ipamorelin is studied and used for stimulating growth hormone production, supporting lean muscle development, improving sleep quality (GH is predominantly released during deep sleep), fat metabolism, and anti-aging protocols. It is one of the most popular peptides in the longevity and performance community due to its clean hormonal profile relative to other GH secretagogues.
Known Risks
While ipamorelin has a relatively favorable safety profile compared to other GH secretagogues, considerations include: potential suppression of natural GH axis with prolonged use, water retention, tingling or numbness at injection sites, and headaches particularly during initial use. Individuals with active malignancies should avoid GH-stimulating peptides as growth hormone can theoretically accelerate tumor growth. Not recommended during pregnancy or breastfeeding. Long-term effects in humans are not well established.
Available Forms
Injectable (subcutaneous). Typically sold as a lyophilized powder requiring reconstitution with bacteriostatic water. Some oral and nasal formulations exist but bioavailability data is limited and injectable remains the standard form used in research and clinical compounding contexts.
Regulatory Status
Ipamorelin is not FDA approved as a standalone drug. However it has been used in licensed compounding pharmacies as a prescription compound, making it one of the more accessible peptides through legitimate clinical channels. Its status in compounding has faced increasing scrutiny — it was added to the FDA's list of difficult to compound drugs in recent years. Consult a licensed provider for current prescribing status in your jurisdiction.
Sources
https://pubmed.ncbi.nlm.nih.gov/9849822/
https://pubmed.ncbi.nlm.nih.gov/10373343/
https://pubmed.ncbi.nlm.nih.gov/9467542/
Similar Compounds
Sermorelin, CJC-1295, GHRP-2, BPC-157
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