Ipamorelin

Overview

Ipamorelin is a synthetic pentapeptide and growth hormone secretagogue (GHS) that stimulates growth hormone release from the pituitary gland. Developed by Novo Nordisk, it acts through the ghrelin (GHS-R) receptor but is notable for its selectivity - it produces GH release without significantly affecting cortisol, prolactin, or ACTH.

This selectivity gives ipamorelin a cleaner side effect profile compared to older GHRPs like GHRP-6 and GHRP-2, making it one of the most popular peptides in the growth hormone secretagogue category.

Sequence: Aib-His-D-2-Nal-D-Phe-Lys-NH2

Mechanism of Action

Ghrelin Receptor (GHS-R1a) Activation

• Binds to growth hormone secretagogue receptor
• Mimics ghrelin's GH-releasing action
• Does NOT significantly increase appetite (unlike ghrelin)
• Selective for GH release

Pituitary Effects

• Stimulates somatotroph cells
• Causes pulsatile GH release
• Preserves physiologic GH pattern
• Works synergistically with GHRH

Selectivity Advantage

Unlike GHRP-6 and GHRP-2, ipamorelin:

• Does NOT significantly elevate cortisol
• Does NOT significantly elevate prolactin
• Does NOT significantly elevate ACTH
• Minimal appetite stimulation

Synergy with GHRH

• GHRH primes pituitary for GH release
• Ipamorelin triggers release
• Combined effect > sum of individual effects
• Often used with Mod GRF 1-29

Research Summary

Clinical Studies

Phase 2 Trial in Post-Surgical Patients

• Evaluated for catabolic state
• Showed GH stimulation
• Well-tolerated
• Program discontinued (business reasons)

GH Release Studies

Key Findings

Selectivity Data (vs GHRP-6):

Comparison to Other GHRPs

• More selective than GHRP-6, GHRP-2
• Similar GH release potency
• Cleaner side effect profile
• Less hunger stimulation

Pharmacokinetics

Common Protocols

Note: Ipamorelin is not approved for human use. The following represents protocols discussed in research communities, not medical recommendations.

Standard Protocol

Typical Dosing:

• 100-300mcg per injection
• 2-3 times daily
• Often combined with Mod GRF 1-29

Common Schedule:

• Morning (fasted)
• Post-workout
• Before bed (30min before sleep)

Combination Protocols

Ipamorelin + Mod GRF 1-29:

• 100mcg each peptide
• 2-3x daily
• Most popular combination
• Synergistic GH release

Saturation Dosing

• 1mcg/kg considered saturation dose
• ~100mcg for most adults
• Higher doses may not proportionally increase effect

Cycle Length

• Typically 8-16 weeks
• Some run continuously
• No established cycling requirement

Administration

Injection Method

• Subcutaneous injection
• Insulin syringes (29-31 gauge)
• Abdomen, thigh, or arm

Reconstitution

• 5mg vial + 2.5mL bacteriostatic water = 2mg/mL (2000mcg/mL)
• Gently swirl, don't shake
• Store at 2-8°C after reconstitution
• Use within 4-6 weeks

Timing Considerations

• Fasted state preferred (30-60 min after last meal)
• Avoid carbs/fats for 30 min after injection
• Fat especially blunts GH response
• Before bed: at least 30 min before sleep

Side Effects

Common (Mild)

• Head rush/flushing (transient)
• Headache
• Tiredness/lethargy (initially)
• Water retention (mild)
• Tingling in extremities

Less Common

• Dizziness
• Nausea (mild)
• Injection site reactions

Rare

• Joint pain
• Carpal tunnel symptoms (with elevated IGF-1)

Advantages Over Other GHRPs

• Minimal hunger stimulation
• No significant cortisol elevation
• No significant prolactin elevation
• Generally very well tolerated

Interactions

Contraindications (Theoretical)

• Active malignancy
• Pregnancy/nursing
• Pituitary disorders

Drug Interactions

• Somatostatin/octreotide (antagonistic)
• Other GH secretagogues (additive)
• GH itself (may reduce efficacy)

Blunting Factors

• High blood glucose
• High insulin
• Somatostatin
• Food (especially fats)

Community Insights

The following represents aggregated reports from online communities and should not be considered medical advice or verified claims.

Commonly Reported Experiences

• Improved sleep quality (most consistent report)
• Enhanced recovery from exercise
• Gradual body composition improvements
• Skin/hair quality improvements noted
• Very well tolerated - "clean" feeling

Why Ipamorelin is Popular

• Minimal side effects compared to GHRP-6/2
• No significant hunger increase
• No cortisol/prolactin issues
• Works well solo or in combinations
• Consistent, predictable effects

Practical Tips Shared

• Combine with Mod GRF for best results
• Timing around food is crucial
• Bedtime dose seems most impactful for sleep
• Lower doses often sufficient
• Quality matters - test if possible

Popular Stacks

• Ipamorelin + Mod GRF 1-29 (gold standard)
• Ipamorelin + CJC-1295 DAC (less common)
• Ipamorelin + Sermorelin (similar to Mod GRF)

Expectations

• Effects are subtle and gradual
• Not like exogenous GH
• 2-3 months for noticeable changes
• Best for anti-aging/recovery, not mass building

References

1. Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-61. [PMID: 9849822]

2. Johansen PB, et al. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999;9(2):106-13. [PMID: 10373343]

3. Gobburu JV, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999;16(9):1412-6. [PMID: 10496657]

4. Jimenez-Reina L, et al. Comparative effects of ipamorelin and GHRP-6 on body weight, bone mass and bone strength in rats. J Bone Miner Res. 1999;14(Suppl 1):S390.

5. Bowers CY. Growth hormone-releasing peptide (GHRP). Cell Mol Life Sci. 1998;54(12):1316-29. [PMID: 9893707]

6. Hansen TK, et al. Dose-dependent effects of growth hormone secretagogue MK-677 on GH and IGF-1 levels in healthy young men. J Clin Endocrinol Metab. 1999;84(12):4326-33. [Background on GH secretagogues]