Mod GRF 1-29 vs MK-677 (Ibutamoren)
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
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 →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 | Mod GRF 1-29 | MK-677 (Ibutamoren) |
|---|---|---|
| Mechanism | 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. | 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, usually combined with a GHRP like Ipamorelin for synergistic effects. | 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 empty stomach. Short half-life (~30 minutes) necessitates multiple daily doses, unlike DAC version. | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. |
| Side Effects | Flushing, headache, dizziness, and injection site reactions. Generally well-tolerated. May cause water retention. | 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
Both Mod GRF 1-29 and MK-677 (Ibutamoren) are commonly used for: