Ipamorelin vs GHRP-2 vs GHRP-6: Choosing the Right GHRP

Written by Adam Maggio | Medically reviewed by Dr. Sarah Chen, PharmD, BCPS

Ipamorelin is the most selective GHRP with the fewest side effects — it stimulates GH release without significantly increasing cortisol, prolactin, or appetite. GHRP-6 is the most potent but causes significant appetite stimulation and cortisol elevation. GHRP-2 falls in between. For most users, Ipamorelin is the preferred GHRP.

The GHRP Family

GHRPs (Growth Hormone-Releasing Peptides) stimulate GH release by binding to the ghrelin receptor (GHSR-1a) in the pituitary gland. Unlike GHRH peptides (Sermorelin, CJC-1295), GHRPs work through a different receptor pathway and produce synergistic GH release when combined with GHRH peptides. The three most commonly used GHRPs are Ipamorelin, GHRP-2, and GHRP-6.

Ipamorelin: The Selective Choice

Ipamorelin is the most selective GHRP — it stimulates GH release with minimal effect on cortisol, prolactin, or appetite. This selectivity makes it the preferred GHRP for most users, particularly those using peptides for anti-aging, recovery, or body composition without wanting the side effects of less selective GHRPs. Typical dosing: 100–300 mcg subcutaneously, 1–3 times daily. Side effects: minimal — occasional water retention, mild fatigue. Best combined with: CJC-1295 without DAC for synergistic GH release.

GHRP-2: The Potent Middle Ground

GHRP-2 is more potent than Ipamorelin for GH stimulation but also increases cortisol and prolactin to a moderate degree. The cortisol elevation is particularly relevant for users concerned about stress response or immune function. GHRP-2 causes less appetite stimulation than GHRP-6. Typical dosing: 100–300 mcg subcutaneously, 1–3 times daily. Side effects: cortisol elevation, mild prolactin increase, moderate appetite stimulation.

GHRP-6: The Appetite Stimulator

GHRP-6 is the most potent GHRP for GH stimulation but causes significant appetite stimulation (due to its strong ghrelin receptor agonism), cortisol elevation, and prolactin increase. The appetite stimulation can be a benefit for individuals trying to increase caloric intake (e.g., hardgainers, cancer patients) but is undesirable for those trying to maintain or reduce body weight. Typical dosing: 100–300 mcg subcutaneously, 1–3 times daily.

Comparison Summary

GH stimulation potency: GHRP-6 > GHRP-2 > Ipamorelin. Selectivity (fewer side effects): Ipamorelin > GHRP-2 > GHRP-6. Appetite stimulation: GHRP-6 >> GHRP-2 > Ipamorelin. Cortisol elevation: GHRP-6 > GHRP-2 > Ipamorelin. For most users seeking anti-aging, recovery, and body composition benefits with minimal side effects, Ipamorelin combined with CJC-1295 without DAC is the optimal choice.