CalcMyPeptide
Growth Hormone

Ipamorelin

Ipamorelin is universally regarded as the cleanest, mildest, and most strategically precise Growth Hormone Secretagogue (GHRP) available in clinical settings. Distinct from earlier generation peptides, Ipamorelin delivers a potent, sustained pulse of Growth Hormone without cross-activating off-target endocrine pathways, meaning it essentially never induces hunger, lethargy, or massive water retention. It is the premier choice for extended, year-round anti-aging protocols, visceral fat loss, and synergistic stacking with Modified GRF(1-29).

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Moderate3 peer-reviewed citations

Quick Stats

Half-Life~2 hours
Dose Range100-300 mcg/injection
Frequency1-3× daily
Vial Sizes2 mg, 5 mg
Bioavailability~100% (subcutaneous)
Year Developed1994

Scientific Data

Molecular Formula
C38H49N9O5
Molecular Weight
711.85 g/mol
CAS Number
PubChem ID
Developer
Novo Nordisk (originally)

Mechanism of Action

Ipamorelin is a highly selective growth hormone secretagogue peptide (GHSP) that acts as a ghrelin receptor (GHS-R1a) agonist. Its defining characteristic is selectivity: unlike GHRP-6 and GHRP-2, Ipamorelin stimulates GH release without significantly elevating cortisol, prolactin, or appetite. This makes it the "cleanest" GH secretagogue available.

Ipamorelin stimulates the pituitary gland to release stored GH in a pulsatile pattern that mimics natural physiology. It is often combined with CJC-1295 (no DAC) for a synergistic GHRH + GHRP effect that maximizes GH output while preserving selectivity.

Source: PMID: 9849822

Background & History

Ipamorelin was discovered by Novo Nordisk researchers in 1998 (Raun et al., European Journal of Endocrinology) as part of a systematic GHRP screening program seeking selectivity. Its defining innovation was near-complete selectivity for GH release without affecting cortisol, prolactin, or ACTH — side effects that plagued first-generation GHRPs (GHRP-6, GHRP-2). This selectivity profile made it the preferred GH secretagogue for research and clinical investigation. It remains the most widely used GHRP in wellness medicine.

Research Use Cases

  • Clean GH pulse stimulation without cortisol elevation
  • Sleep quality improvement via GH-mediated slow-wave sleep enhancement
  • Body recomposition: lean muscle gain and fat oxidation
  • Recovery acceleration appropriate for long-term use
  • Anti-aging GH restoration in somatopause

Dosing Protocol

Typical Dose100-300 mcg/injection
Frequency1-3× daily
Half-Life~2 hours
Common Vial Sizes2 mg, 5 mg

Dosing Protocols

Standard Protocol

Dose
100 - 200 mcg
Frequency
1-3× daily
Note: Inject fasted. 1hr no food before, 30min after. Most popular: before bed + upon waking.

Stacked with CJC-1295

Dose
100 mcg Ipamorelin + 100 mcg CJC-1295 No DAC
Frequency
1-3× daily
Note: Industry gold-standard GH stack. Synergistic amplitude and initiation.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 100300 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)77 mcg154 mcg231 mcg
140 lb(63 kg)90 mcg180 mcg270 mcg
160 lb(73 kg)104 mcg209 mcg313 mcg
180 lb(82 kg)117 mcg234 mcg351 mcg
200 lb(91 kg)130 mcg260 mcg390 mcg
220 lb(100 kg)143 mcg286 mcg429 mcg
250 lb(113 kg)161 mcg323 mcg484 mcg

💉 For exact syringe units based on your vial concentration, use the Ipamorelin Reconstitution Calculator →

Administration

Route
Subcutaneous injection
Timing
Must be injected fasted. Most common: before sleep (aligns with nighttime GH surge) and/or upon waking.
Fasting Required?
Yes — inject on an empty stomach

Expected Timeline

Week 1-2
Improved sleep depth and quality. Faster recovery between training sessions.
Month 1-2
Gradual body composition improvements: increased lean mass, mild fat reduction.
Month 3+
Compounding IGF-1 elevation and sustained body recomposition.

Who Is It For?

GH Optimization (Clean)

High

Selective GH release without cortisol, prolactin, or appetite spikes — the cleanest GHRP.

Anti-Aging / Longevity

Moderate

Long-term GH/IGF-1 support with minimal systemic side effects.

Reconstitution Example

Vial
5 mg
Water
2.5 mL
Concentration
2 mg/mL
Per Unit (100u syringe)
20 mcg
Dose of 100 mcg = 5 units on a 100-unit insulin syringe

Safety & Considerations

Research peptide with a favorable safety profile in studies. May cause transient headache or lightheadedness. Minimal effect on cortisol, prolactin, or appetite (unlike GHRP-6). Inject on an empty stomach for optimal GH pulse.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Prohibited (S2)

Competitive athletes subject to anti-doping controls should not use Ipamorelin.

Classification

Compounded Drug (Rx)

US Compounding: Available via licensed pharmacy Rx

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Interactions & Contraindications

Inject on empty stomach — food/insulin blunts response by 60–80%. Do not combine with growth hormone if IGF-1 is already elevated. Somatostatin analogs (octreotide) antagonize GH release. Hypothyroidism reduces GH receptor sensitivity — address thyroid function first.

Synergies & Common Stacks

+ CJC-1295 no DAC

The most popular GH secretagogue stack: Mod GRF amplifies pulse amplitude while Ipamorelin provides the clean selective stimulation. Produces 2–5× more GH than either alone.

For convenience-focused protocols: once-weekly CJC-1295 DAC with daily Ipamorelin injections. Provides sustained baseline GH with clean daily pulses.

Recovery stack combining systemic tissue repair (BPC-157) with GH-mediated anabolic and regenerative signals (Ipamorelin).

Ipamorelin vs. GHRP-6

AttributeIpamorelinGHRP-6
SelectivityHigh — GH only, no cortisol/prolactinLow — GH + cortisol + prolactin + ghrelin
Appetite EffectMinimal stimulationStrong appetite stimulation
GH OutputModerate, clean, dose-dependentStrong, non-selective pulse
Best ForAnti-aging, long-term clean protocolMuscle building, caloric surplus phase
Side EffectsMinimal (transient water retention)More (hunger, cortisol elevation)

Verdict: Ipamorelin is cleaner and better tolerated for long-term use. GHRP-6 is better for appetite-driven muscle-building phases where hunger stimulation is a feature, not a bug.

Ipamorelin vs. CJC-1295 (No DAC)

AttributeIpamorelinCJC-1295 (No DAC)
ClassGHRP (ghrelin mimetic)GHRH analog (growth hormone-releasing hormone)
MechanismTriggers GH pulse via pituitaryAmplifies GH pulse amplitude
Stacked TogetherIndustry gold-standard combinationIndustry gold-standard combination
Half-Life~2 hours~30 minutes
Solo EffectivenessModerate GH pulse aloneModerate amplitude increase alone

Verdict: Ipamorelin + CJC-1295 (No DAC) is the most widely used GH optimization stack in current protocols. They are complementary, not competing: GHRP initiates the pulse, GHRH amplifies it.

Dosing Quick Reference

Ipamorelin— Dosing Guide
Dose Range
100-300 mcg/injection
Half-Life
~2 hours
Frequency
1-3× daily
Route
Subcutaneous
2 mg vial5 mg vial
💧 2.5 mL BAC water📐 2 mg/mL concentration💉 20 mcg/unit (100u syringe)
Growth Hormonecalcmypeptide.com

Frequently Asked Questions

What makes Ipamorelin better than GHRP-6?
Ipamorelin is more selective — it stimulates GH release without significantly raising cortisol, prolactin, or appetite. GHRP-6 strongly stimulates hunger (via ghrelin pathway), which many users find undesirable.
What is the standard Ipamorelin dose?
100-300 mcg per injection, 1-3 times daily on an empty stomach. Most commonly used at 100-200 mcg combined with 100 mcg CJC-1295 (no DAC).
How long does it take to see results from Ipamorelin?
Sleep quality improvements are often noticed within the first 1-2 weeks. Body composition changes typically require 8-12 weeks of consistent dosing.

References

  1. Raun et al. "Ipamorelin, the first selective growth hormone secretagogue".” European Journal of Endocrinology (1998). PMID: 9849822

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