Hexarelin vs IGF-1 LR3 vs MK-677 (Ibutamoren)
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 →IGF-1 LR3
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a modified version of IGF-1 with extended half-life and enhanced potency. The modifications prevent binding to IGF binding proteins, increasing bioavailability.
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 | Hexarelin | IGF-1 LR3 | MK-677 (Ibutamoren) |
|---|---|---|---|
| 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. | Binds to IGF-1 receptors to promote protein synthesis, muscle growth, and fat metabolism. The LR3 modification (13 amino acid extension and arginine substitution) extends half-life from minutes to 20-30 hours. | 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: 100-200mcg administered 2-3 times daily for 4-6 weeks, followed by an equal off period to allow receptor resensitization. | Research protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles. | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. |
| Administration | Subcutaneous injection. Cycling is essential to maintain effectiveness. Often used in short bursts rather than continuous protocols. | Intramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off. | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. |
| Side Effects | Water retention, cortisol and prolactin increase, hunger (moderate), tingling, and potential blood pressure effects. | Hypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions. | 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
Hexarelin, IGF-1 LR3, MK-677 (Ibutamoren) are all commonly used for:
Key Differences
Unique to IGF-1 LR3:
Unique to MK-677 (Ibutamoren):
Detailed Analysis
Commonalities
Both Hexarelin and IGF-1 LR3 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 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 IGF-1 LR3 and MK-677 (Ibutamoren) are commonly used for Muscle Growth, Fat Loss, 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.