Hexarelin vs MK-677 (Ibutamoren) vs Mod GRF 1-29
A three-way comparison to help you find the right peptide for your research goals.
Hexarelin
Hexarelin is a potent synthetic hexapeptide growth hormone secretagogue. It provides the strongest GH release among GHRPs but is associated with rapid desensitization of receptors.
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 | Hexarelin | MK-677 (Ibutamoren) | Mod GRF 1-29 |
|---|---|---|---|
| Mechanism | Acts as a ghrelin mimetic with high potency at the GHS receptor. Provides powerful GH release but receptor desensitization occurs faster than with other GHRPs, requiring cycling. | 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 | Typical dosing: 100-200mcg administered 2-3 times daily for 4-6 weeks, followed by an equal off period to allow receptor resensitization. | 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 | Subcutaneous injection. Cycling is essential to maintain effectiveness. Often used in short bursts rather than continuous protocols. | 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 | Water retention, cortisol and prolactin increase, hunger (moderate), tingling, and potential blood pressure 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
Hexarelin, 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 Hexarelin 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 Hexarelin and Mod GRF 1-29 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 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.