Ipamorelin
Also known as: IPA, Ipamorelin Acetate, NNC 26-0161
Ipamorelin is a selective growth hormone secretagogue (GHS) that stimulates growth hormone release through the ghrelin receptor. It is considered one of the cleanest GH-releasing peptides due to its selectivity; it elevates GH without significantly affecting cortisol, prolactin, or appetite.
Ipamorelin is a 711.85 Da research peptide. Ipamorelin is a selective growth hormone secretagogue (GHS) that stimulates growth hormone release through the ghrelin receptor. It is considered one of the cleanest GH-releasing peptides due to its selectivity; it elevates GH without significantly affecting cortisol, prolactin, or appetite.
Also called: IPA, Ipamorelin Acetate, NNC 26-0161
711.85
Molecular Weight
Daltons
2
Strong Evidence
benefits
5
Studies Cited
peer-reviewed
200-300
Typical Dose
mcg
Overview
Ipamorelin is a synthetic pentapeptide (five amino acids) that acts as a selective agonist of the growth hormone secretagogue receptor (GHS-R), also known as the ghrelin receptor. Developed by Novo Nordisk, it was one of the first GH secretagogues designed for improved selectivity over earlier compounds like GHRP-6 and GHRP-2. What distinguishes Ipamorelin from other ghrelin mimetics is its notable selectivity: it stimulates growth hormone release with minimal impact on cortisol, aldosterone, prolactin, and appetite. This is in contrast to GHRP-6, which strongly stimulates hunger, and GHRP-2, which can elevate cortisol and prolactin. This selectivity profile has made Ipamorelin a preferred research compound for studying GH-axis modulation. It produces dose-dependent GH release in a manner similar to natural GH-releasing hormone (GHRH) but through a completely different receptor pathway, making it complementary to GHRH analogues like CJC-1295. Ipamorelin has been studied in clinical trials for post-surgical recovery and gastrointestinal function.
Key Takeaways: Ipamorelin
- Strongest evidence supports Ipamorelin for selective gh release and favorable safety profile
- Research doses typically range from 200 to 300 mcg via subcutaneous injection
- 2 benefits with strong evidence, 3 moderate, 0 preliminary
- Half-life: Approximately 2 hours
- 5 cited research studies in this guide
Mechanism of Action
Ipamorelin binds to the growth hormone secretagogue receptor (GHS-R1a) on somatotroph cells in the anterior pituitary gland. This receptor is the same target as ghrelin, the endogenous "hunger hormone." Upon binding, Ipamorelin activates phospholipase C and inositol triphosphate (IP3) signaling, leading to intracellular calcium release and subsequent growth hormone exocytosis. Unlike GHRP-6, Ipamorelin does not significantly activate the GHS-R in hypothalamic neurons that regulate appetite (NPY/AgRP neurons), which explains its minimal effect on hunger. It also shows very low affinity for receptors that trigger cortisol release from the adrenal cortex. The GH release produced by Ipamorelin follows a dose-dependent curve up to a saturation point (approximately 1 mcg/kg body weight), beyond which additional dosing does not meaningfully increase GH output. Importantly, Ipamorelin's mechanism is complementary to GHRH signaling: GHRH works through cAMP/PKA pathway while Ipamorelin works through PLC/IP3/calcium. When combined, these two pathways produce combined GH release substantially greater than either alone, which is why the CJC-1295 + Ipamorelin combination is one of the most widely researched peptide protocols.
Research Benefits
Ipamorelin at a Glance
Ipamorelin binds to the growth hormone secretagogue receptor (GHS-R1a) on somatotroph cells in the anterior pituitary gland.
Selective GH Release
Strong EvidenceClinical studies demonstrate dose-dependent GH release comparable to GHRP-6 but without the elevations in cortisol, prolactin, or appetite. This makes it one of the most targeted GH-releasing peptides available for research.
Favorable Safety Profile
Strong EvidenceClinical trials including Phase II studies have shown Ipamorelin is well-tolerated with minimal side effects. Its selectivity reduces the risk of unwanted hormonal perturbations seen with less selective GH secretagogues.
Post-Surgical GI Recovery
Moderate EvidenceA Phase II clinical trial studied Ipamorelin for post-operative ileus (delayed gut recovery after abdominal surgery) and showed trends toward faster recovery of bowel function.
Bone Density Support
Moderate EvidenceAnimal studies have shown that GH secretagogues including Ipamorelin can increase bone mineral content and bone formation rate, potentially relevant to osteoporosis research.
Improved Body Composition
Moderate EvidenceThrough sustained GH elevation, Ipamorelin may support improvements in lean mass and reductions in adipose tissue, consistent with known GH/IGF-1 axis effects on body composition.
Sleep Quality Enhancement
AnecdotalAnecdotal research reports suggest improved sleep quality and deeper slow-wave sleep when Ipamorelin is administered before bedtime, consistent with GH's role in sleep architecture.
Research Dosing Protocols
Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
| Research Protocol | Dose Range | Route |
|---|---|---|
| Standard protocol | 200–300 mcg | Subcutaneous injection |
| Combined with Mod GRF 1-29 | 100–200 mcg | Subcutaneous injection |
| Pre-sleep protocol | 200–300 mcg | Subcutaneous injection |
Frequency
1-3 times daily
Timing
Morning (fasted), post-workout, and/or 30 min before bed. Avoid dosing within 2 hours of eating.
Cycle Length
8-16 weeks, with some protocols running indefinitely with periodic breaks
Research Notes
- 1Saturation dose is approximately 1 mcg/kg body weight (~100 mcg for most adults). Higher doses show diminishing returns.
- 2Most commonly combined with Mod GRF 1-29 (CJC-1295 no DAC) at a 1:1 ratio.
- 3Fasting for 2+ hours before administration maximizes GH pulse amplitude.
- 4Carbohydrates and fats suppress GH release, time doses away from meals.
- 5The pre-bed dose is often considered most important, aligning with natural nocturnal GH peak.
- 6Unlike GHRP-6, Ipamorelin does not cause significant hunger — useful for body composition research.
Reconstitution Guide
Standard Reconstitution
Vial Size
5 mg
Bacteriostatic Water
2.5 mL
Concentration
20 mcg
per 0.1 mL (10 units)
Step-by-Step Guide
Gather Materials
Ipamorelin vial, bacteriostatic water, alcohol swabs, insulin syringes.
Equilibrate Temperature
Remove the vial from storage and allow it to reach room temperature (5-10 minutes).
Sanitize
Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.
Draw Water
Draw 2.5 mL of bacteriostatic water into a syringe.
Add Water to Vial
Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.
Mix Gently
Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.
Store Properly
Refrigerate at Refrigerated (2-8°C / 36-46°F) after reconstitution. Up to 30 days refrigerated after reconstitution.
Storage Temperature
Refrigerated (2-8°C / 36-46°F) after reconstitution
Shelf Life
Up to 30 days refrigerated after reconstitution
Important Notes
- •Use bacteriostatic water for multi-use vials.
- •Store lyophilized vials frozen (-20°C) for long-term storage.
- •Vials commonly available in 2 mg and 5 mg sizes.
- •Swirl gently, never shake.
- •Solution should be clear and colorless.
- •2.5 mL of water in a 5 mg vial = 2,000 mcg/mL (convenient for 200 mcg = 10 units).
Ipamorelin Dosing Calculator
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Ipamorelin Reconstitution Calculator
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Safety & Side Effects
Reported Side Effects
- !Injection site irritation; mild redness or soreness (transient)
- !Headache (reported occasionally, usually mild)
- !Water retention — mild bloating during initial use
- !Lightheadedness shortly after injection
- !Tingling in hands or feet (related to GH-mediated fluid shifts)
- !Does NOT typically cause increased hunger (unlike GHRP-6)
- !Does NOT typically elevate cortisol or prolactin at standard research doses
- !Long-term safety data from controlled human studies is limited
Potential Interactions
- ⚡complementary with GHRH analogues (CJC-1295, Mod GRF 1-29); combined use amplifies GH release significantly.
- ⚡Somatostatin and analogues (octreotide) will suppress GH release stimulated by Ipamorelin.
- ⚡May interact with insulin and diabetes medications, GH has diabetogenic effects.
- ⚡Glucocorticoids may blunt the GH response.
- ⚡Avoid concurrent high-dose insulin administration — insulin suppresses GH release.
- ⚡No formal drug interaction studies specific to Ipamorelin have been published.
Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.
Research Studies
The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.
Safety, pharmacokinetics, and pharmacodynamics of ipamorelin, a novel ghrelin mimetic, in healthy volunteers
Demonstrated Ipamorelin's selective GH-releasing activity without significant effects on cortisol, aldosterone, or prolactin, establishing its favorable selectivity profile compared to other GH secretagogues.
Ipamorelin, the first selective growth hormone secretagogue
Foundational paper establishing Ipamorelin as the most selective GH secretagogue, with dose-dependent GH release and minimal impact on ACTH, cortisol, prolactin, TSH, LH, and FSH.
Ipamorelin for postoperative ileus: a randomized, double-blind, placebo-controlled phase 2b/3 trial
Phase II/III trial evaluating Ipamorelin for accelerating recovery of GI function after abdominal surgery. Showed trends toward faster time to first bowel movement and hospital discharge.
Growth hormone secretagogues increase bone formation
Demonstrated that GH secretagogues including Ipamorelin increase markers of bone formation and bone mineral content in animal models, suggesting potential applications in bone health research.
Synergy between growth hormone-releasing hormone and growth hormone secretagogues
Established the scientific basis for combining GHRH with ghrelin mimetics, showing that the two pathways produce amplified GH release through complementary intracellular signaling mechanisms.
Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.
Frequently Asked Questions
Ipamorelin is a synthetic five-amino acid peptide that selectively stimulates growth hormone release through the ghrelin receptor (GHS-R). It is considered the most selective GH secretagogue due to its minimal effects on cortisol, prolactin, and appetite.
Both are ghrelin mimetics that stimulate GH release, but Ipamorelin is far more selective. GHRP-6 causes significant hunger, can elevate cortisol and prolactin, and has broader hormonal effects. Ipamorelin stimulates GH with minimal impact on other hormones or appetite.
They work through completely different receptor pathways (ghrelin receptor vs. GHRH receptor). When combined, they produce amplified GH release, typically 2-3x more than either alone. The CJC-1295 + Ipamorelin stack is one of the most widely researched peptide combinations.
No, unlike GHRP-6 which strongly stimulates appetite, Ipamorelin has minimal effect on hunger. This is because it does not significantly activate the hypothalamic neurons (NPY/AgRP) that regulate appetite, despite acting on the same receptor type.
Research protocols typically administer Ipamorelin on an empty stomach; either in the morning (fasted), post-workout, or before bed. The pre-bed dose is often emphasized to amplify the natural nocturnal GH pulse. Avoid eating within 2 hours of dosing.
No. Ipamorelin is not FDA-approved for any clinical use. It progressed through Phase II clinical trials for post-operative ileus but has not received regulatory approval. It remains a research compound.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.