GHRP-6 vs Ipamorelin vs MK-677 (Ibutamoren)
A three-way comparison to help you find the right peptide for your research goals.
GHRP-6
Growth Hormone Releasing Peptide 6 (GHRP-6) is one of the first synthetic growth hormone secretagogues discovered. It stimulates significant GH release but is known for causing intense hunger.
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-6 | Ipamorelin | MK-677 (Ibutamoren) |
|---|---|---|---|
| Mechanism | Acts as a ghrelin mimetic, binding to the GHS-R receptor in the pituitary and hypothalamus. Stimulates GH release and also significantly increases appetite by mimicking ghrelin's hunger-signaling effects. | 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 combined with GHRH peptides like CJC-1295 for synergistic effects. | 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. Best administered on an empty stomach. The strong hunger response can be beneficial for those trying to gain weight but challenging for cutting. | 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 | Intense hunger (most notable effect), water retention, increased cortisol and prolactin, tingling/numbness, and potential blood pressure changes. | 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-6, Ipamorelin, MK-677 (Ibutamoren) are all commonly used for:
Key Differences
Unique to Ipamorelin:
Unique to MK-677 (Ibutamoren):
Detailed Analysis
Commonalities
Both GHRP-6 and Ipamorelin are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
Both peptides have similar evidence levels for their shared goals. Your choice may depend on specific use case, availability, or personal response.
Commonalities
Both GHRP-6 and MK-677 (Ibutamoren) are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
Both peptides have similar evidence levels for their shared goals. Your choice may depend on specific use case, availability, or personal response.
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.