GHRP-2 vs Ipamorelin vs MK-677 (Ibutamoren)
A three-way comparison to help you find the right peptide for your research goals.
GHRP-2
Growth Hormone Releasing Peptide 2 (GHRP-2) is considered one of the most potent GHRPs available. It provides strong GH release with moderate hunger increase compared to GHRP-6.
Full details →Ipamorelin
Ipamorelin is a selective growth hormone secretagogue that stimulates the release of growth hormone from the pituitary gland without significantly affecting cortisol or prolactin.
Full details →MK-677 (Ibutamoren)
MK-677, also known as Ibutamoren, is an orally active growth hormone secretagogue. Unlike peptides, it can be taken orally and has a long half-life, providing 24-hour GH elevation.
Full details →Side-by-Side Comparison
| Aspect | GHRP-2 | Ipamorelin | MK-677 (Ibutamoren) |
|---|---|---|---|
| Mechanism | Binds to the ghrelin receptor (GHS-R) to stimulate GH release from the pituitary. Also has some direct effects on the hypothalamus. Causes less appetite increase than GHRP-6. | Acts as a ghrelin mimetic, binding to the ghrelin receptor (GHS-R) in the pituitary to stimulate GH release. Highly selective with minimal effect on other hormones. | Acts as a potent, selective agonist of the ghrelin receptor (GHS-R1a). Increases GH and IGF-1 levels without affecting cortisol. Mimics ghrelin's GH-releasing effects. |
| Typical Dosage | Typical dosing: 100-300mcg administered 2-3 times daily. Often stacked with GHRH peptides for enhanced GH release. | Typical dosing ranges from 200-300mcg administered 2-3 times daily, often combined with CJC-1295. | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. |
| Administration | Subcutaneous injection on an empty stomach. Can be used at bedtime to enhance natural GH pulse during sleep. | Subcutaneous injection. Best results when administered fasted or before sleep. Often stacked with GHRH peptides. | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. |
| Side Effects | Moderate hunger increase, water retention, potential prolactin and cortisol elevation (less than GHRP-6), tingling sensations. | Generally well-tolerated. May cause mild headaches, lightheadedness, or increased hunger initially. | Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity. |
| Best For |
What They Have in Common
GHRP-2, Ipamorelin, MK-677 (Ibutamoren) are all commonly used for:
Key Differences
Unique to Ipamorelin:
Unique to MK-677 (Ibutamoren):
Detailed Analysis
Commonalities
Both GHRP-2 and Ipamorelin are commonly used for Muscle Growth, Fat Loss, Sleep Quality.
Which Should You Choose?
Ipamorelin has stronger evidence for Fat Loss, Sleep Quality.
Commonalities
Both GHRP-2 and MK-677 (Ibutamoren) are commonly used for Muscle Growth, Fat Loss, Sleep Quality.
Which Should You Choose?
MK-677 (Ibutamoren) has stronger evidence for Sleep Quality.
Commonalities
Both Ipamorelin and MK-677 (Ibutamoren) are commonly used for Muscle Growth, Fat Loss, Recovery & Healing, Sleep Quality.
Which Should You Choose?
Ipamorelin has stronger evidence for Fat Loss.