OnePin Peptide Library · Growth Hormone
Ipamorelin
Ipa
Ipamorelin is a synthetic pentapeptide growth hormone secretagogue that selectively stimulates growth hormone release from the anterior pituitary by acting as a ghrelin receptor (GHS-R1a) agonist. It is distinguished from older GHRPs (GHRP-2, GHRP-6, Hexarelin) by its high selectivity: Ipamorelin does not significantly affect cortisol, prolactin, or appetite at standard doses, making it the cleanest GHRP available. It produces acute GH pulses with a plasma half-life of approximately 2 hours. Ipamorelin is discussed in the context of GH axis optimization, body composition improvement, recovery enhancement, sleep support, and anti-aging protocols, most commonly paired with a GHRH analog (Tesamorelin or CJC-1295 no DAC) for synergistic dual-pathway GH release.
Best administered on empty stomach, at least 2 hours after last meal. Do not eat for 30-60 minutes after injection. Bedtime dosing preferred for natural GH pulse amplification. Fasting is critical.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
Ipamorelin binds to the growth hormone secretagogue receptor (GHS-R1a), also known as the ghrelin receptor, on somatotroph cells in the anterior pituitary. This triggers GH release through a pathway distinct from GHRH receptor activation. Ipamorelin amplifies GH pulse frequency while GHRH analogs amplify pulse amplitude, which is why the combination produces 3-5x greater total GH output than either alone. The selectivity of Ipamorelin comes from its minimal activation of other pituitary hormone pathways: unlike GHRP-2 and GHRP-6, it does not significantly stimulate ACTH (and therefore cortisol), prolactin, or appetite. GH release from Ipamorelin is still modulated by somatostatin, meaning the body's natural feedback mechanisms remain intact.
Ipamorelin binds to the growth hormone secretagogue receptor (GHS-R1a), also known as the ghrelin receptor, on somatotroph cells in the anterior pituitary. This triggers GH release through a pathway distinct from GHRH receptor activation. Ipamorelin amplifies GH pulse frequency while GHRH analogs amplify pulse amplitude, which is why the combination produces 3-5x greater total GH output than either alone. The selectivity of Ipamorelin comes from its minimal activation of other pituitary hormone pathways: unlike GHRP-2 and GHRP-6, it does not significantly stimulate ACTH (and therefore cortisol), prolactin, or appetite. GH release from Ipamorelin is still modulated by somatostatin, meaning the body's natural feedback mechanisms remain intact.
What to expect
Days 1-7: Improved sleep quality is typically the first effect. Transient flushing or warmth after injection is normal. Some users notice increased appetite. No significant body composition changes expected yet.
Weeks 2-6: Recovery improvements become noticeable. Sleep quality consistently better. Skin begins to look more hydrated. Body composition changes starting if paired with proper diet and training. Lab work should show elevated GH and IGF-1.
Weeks 6-16: Significant body composition improvements when combined with GHRH analog. Fat loss, lean mass preservation, improved recovery. Collagen synthesis benefits become apparent (skin, joints). Monitor IGF-1 levels periodically.
Evidence
The honest take
Selective GH release
SupportedConfirmed by human PK/PD studies. Ipamorelin does not significantly affect cortisol, prolactin, or ACTH at standard doses. This is its primary advantage over GHRP-2 and GHRP-6.
Human clinical trials showed accelerated recovery of bowel function post-surgery. One of the few human clinical data points for any GHRP.
GH axis optimization is a cornerstone of anti-aging medicine. Effects on sleep, body composition, skin, and recovery support this application. Not a validated anti-aging treatment by itself.
Interactions & stacking
What's safe to combine, and what belongs in a separate pin.
Safe & synergistic
Keep separate
Side effects & safety
Commonly reported
- Transient flushing or warmth at injection site (normal, resolves in minutes)
- Mild water retention (typically first 1-2 weeks)
- Increased appetite in some users (much less than GHRP-2/6)
- Occasional headache
Less common & notes
- Joint pain or stiffness from elevated GH/IGF-1 (dose-dependent, resolves with dose reduction).
- Numbness or tingling in extremities (carpal tunnel-like, from fluid retention).
- Very rare reports of dizziness.
- Monitor fasting glucose as GH elevation can affect insulin sensitivity.
- Contraindicated in active malignancy due to IGF-1 elevation.
Pharmacokinetics
Storage. Store unreconstituted vials frozen (-20C) or refrigerated (2-8C). After reconstitution with BAC water, refrigerate at 2-8C. Stable for 28 days. Commonly sold pre-mixed with CJC-1295 no DAC, which has a shorter shelf life (14-21 days) that becomes the limiting factor for the blend. Protect from light. Do not freeze after reconstitution.
Regulatory status
Ipamorelin is not FDA-approved for any indication. It is classified as a research peptide. WADA prohibits Ipamorelin under S2 Growth Hormone Secretagogues. Available through research chemical and compounding channels. Regulatory status should be verified against current governing body rules before use.
Put it to work
Calculate, log & track
Open Ipamorelin straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.
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The guide & community
The complete Ipamorelin walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
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