Ipamorelin vs MK-677 (Ibutamoren) vs Tesamorelin
A three-way comparison to help you find the right peptide for your research goals.
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 →Tesamorelin
Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH). It is FDA-approved under the brand name Egrifta for reducing excess abdominal fat in HIV-infected patients with lipodystrophy.
Full details →Side-by-Side Comparison
| Aspect | Ipamorelin | MK-677 (Ibutamoren) | Tesamorelin |
|---|---|---|---|
| Mechanism | 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. | Stimulates the pituitary gland to produce and release growth hormone by binding to GHRH receptors. Increases IGF-1 levels which promotes lipolysis and reduces visceral adipose tissue. |
| Typical Dosage | 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. | FDA-approved dose: 2mg administered subcutaneously once daily. Research protocols may use various dosing schedules. |
| Administration | 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. | Subcutaneous injection into the abdomen. Rotate injection sites. Best administered at the same time daily, preferably in the evening. |
| Side Effects | 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. | Common side effects include injection site reactions (erythema, pruritus), joint pain, peripheral edema, and muscle pain. May cause elevated blood glucose. |
| Best For |
What They Have in Common
Ipamorelin, MK-677 (Ibutamoren), Tesamorelin are all commonly used for:
Key Differences
Unique to Ipamorelin:
Unique to MK-677 (Ibutamoren):
Detailed Analysis
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.
Commonalities
Both Ipamorelin and Tesamorelin are commonly used for Muscle Growth, Fat Loss.
Which Should You Choose?
Ipamorelin has stronger evidence for Muscle Growth.
Commonalities
Both MK-677 (Ibutamoren) and Tesamorelin are commonly used for Muscle Growth, Fat Loss.
Which Should You Choose?
MK-677 (Ibutamoren) has stronger evidence for Muscle Growth. Tesamorelin has stronger evidence for Fat Loss.