MGF (Mechano Growth Factor) vs MK-677 (Ibutamoren) vs Mod GRF 1-29
A three-way comparison to help you find the right peptide for your research goals.
MGF (Mechano Growth Factor)
MGF (Mechano Growth Factor) is a splice variant of IGF-1 that is produced locally in muscle tissue in response to mechanical stress. The non-PEGylated form has a very short half-life.
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 →Mod GRF 1-29
Mod GRF 1-29 (Modified GRF 1-29, also called CJC-1295 without DAC or Tetrasubstituted GRF 1-29) is a modified growth hormone-releasing hormone analog with improved stability over natural GHRH.
Full details →Side-by-Side Comparison
| Aspect | MGF (Mechano Growth Factor) | MK-677 (Ibutamoren) | Mod GRF 1-29 |
|---|---|---|---|
| Mechanism | Activates muscle satellite cells (stem cells) and promotes their proliferation without differentiation, priming them for fusion with existing muscle fibers during repair and growth. | 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. | Binds to GHRH receptors in the pituitary gland to stimulate growth hormone release. Four amino acid substitutions improve resistance to enzymatic degradation while maintaining biological activity. |
| Typical Dosage | Due to extremely short half-life (minutes), typical protocols use 100-200mcg injected directly into target muscles immediately post-workout. | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. | Typical dosing: 100-300mcg administered 2-3 times daily, usually combined with a GHRP like Ipamorelin for synergistic effects. |
| Administration | Intramuscular injection into trained muscles within minutes of workout completion. Must be used immediately after reconstitution due to instability. | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. | Subcutaneous injection. Best administered on empty stomach. Short half-life (~30 minutes) necessitates multiple daily doses, unlike DAC version. |
| Side Effects | Injection site soreness, potential hypoglycemia, localized swelling. Short half-life limits systemic effects. | Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity. | Flushing, headache, dizziness, and injection site reactions. Generally well-tolerated. May cause water retention. |
| Best For |
What They Have in Common
MGF (Mechano Growth Factor), MK-677 (Ibutamoren), Mod GRF 1-29 are all commonly used for:
Key Differences
Unique to MK-677 (Ibutamoren):
Unique to Mod GRF 1-29:
Detailed Analysis
Commonalities
Both MGF (Mechano Growth Factor) and MK-677 (Ibutamoren) are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
MK-677 (Ibutamoren) has stronger evidence for Muscle Growth.
Commonalities
Both MGF (Mechano Growth Factor) and Mod GRF 1-29 are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
Mod GRF 1-29 has stronger evidence for Muscle Growth.
Commonalities
Both MK-677 (Ibutamoren) and Mod GRF 1-29 are commonly used for Muscle Growth, Fat Loss, Recovery & Healing, Sleep Quality.
Which Should You Choose?
MK-677 (Ibutamoren) has stronger evidence for Sleep Quality.