MK-677 (Ibutamoren) vs MOTS-c vs Sermorelin
A three-way comparison to help you find the right peptide for your research goals.
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 →MOTS-c
MOTS-c (Mitochondrial Open Reading Frame of the Twelve S rRNA type-c) is a mitochondrial-derived peptide that plays a key role in metabolic regulation and has emerged as a significant longevity research target.
Full details →Sermorelin
Sermorelin is a synthetic analog of GHRH consisting of the first 29 amino acids of the natural hormone. It was previously FDA-approved for GH deficiency diagnosis and treatment in children.
Full details →Side-by-Side Comparison
| Aspect | MK-677 (Ibutamoren) | MOTS-c | Sermorelin |
|---|---|---|---|
| Mechanism | 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. | Activates AMPK pathway, enhances glucose uptake in skeletal muscle, improves insulin sensitivity, and regulates mitochondrial function. Acts as a metabolic hormone affecting whole-body energy homeostasis. | Binds to GHRH receptors in the pituitary gland to stimulate natural GH production and release. Maintains the body's natural feedback mechanisms for GH regulation. |
| Typical Dosage | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. | Research protocols typically use 5-10mg administered subcutaneously several times per week. Optimal dosing not yet established. | Typical dosing: 200-500mcg administered once daily, usually before bed. Some protocols use twice daily dosing. |
| Administration | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. | Subcutaneous injection. Often combined with exercise protocols as it enhances exercise capacity and metabolic adaptation. | Subcutaneous injection, preferably at bedtime to work with natural GH release patterns. Can be combined with GHRPs for synergistic effects. |
| Side Effects | Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity. | Limited human data. Animal studies show good tolerability. May affect energy levels and exercise performance. | Generally well-tolerated. May cause injection site reactions, headache, flushing, or dizziness. Less side effects than direct GH administration. |
| Best For |
What They Have in Common
MK-677 (Ibutamoren), MOTS-c, Sermorelin are all commonly used for:
Key Differences
Unique to MK-677 (Ibutamoren):
Unique to MOTS-c:
Unique to Sermorelin:
Detailed Analysis
Commonalities
Both MK-677 (Ibutamoren) and MOTS-c are commonly used for Muscle Growth, Fat Loss.
Which Should You Choose?
MK-677 (Ibutamoren) has stronger evidence for Muscle Growth.
Commonalities
Both MK-677 (Ibutamoren) and Sermorelin are commonly used for Muscle Growth, Fat Loss, Recovery & Healing, Sleep Quality.
Which Should You Choose?
MK-677 (Ibutamoren) has stronger evidence for Muscle Growth, Sleep Quality.
Commonalities
Both MOTS-c and Sermorelin are commonly used for Muscle Growth, Fat Loss.
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.