Human Growth Hormone (HGH) vs MK-677 (Ibutamoren) vs PEG-MGF
A three-way comparison to help you find the right peptide for your research goals.
Human Growth Hormone (HGH)
Human Growth Hormone (somatropin) is a 191-amino acid protein identical to naturally produced GH. FDA-approved for growth hormone deficiency, Turner syndrome, and other conditions. Widely used off-label for anti-aging and performance.
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 →PEG-MGF
PEG-MGF (PEGylated Mechano Growth Factor) is a variant of IGF-1 that is produced in response to muscle damage. PEGylation extends its half-life from minutes to several hours, making it practical for use.
Full details →Side-by-Side Comparison
| Aspect | Human Growth Hormone (HGH) | MK-677 (Ibutamoren) | PEG-MGF |
|---|---|---|---|
| Mechanism | Binds to GH receptors throughout the body, stimulating IGF-1 production in the liver. Promotes protein synthesis, fat metabolism, and cellular regeneration across multiple tissues. | 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 muscle satellite cells (stem cells) and promotes their fusion to existing muscle fibers for repair and growth. MGF is produced naturally in response to mechanical stress on muscles. |
| Typical Dosage | Medical: 0.1-0.3mg/kg/week divided into daily doses. Anti-aging: 1-2 IU daily. Performance: 2-6 IU daily, sometimes higher. | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. | Research protocols typically use 200-400mcg injected into targeted muscle groups 2-3 times weekly, usually post-workout. |
| Administration | Subcutaneous injection, preferably at night to mimic natural pulsatile release. Rotate injection sites. Store refrigerated. | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. | Intramuscular injection, ideally into muscles trained that day. Best administered post-workout when satellite cell activation is relevant. |
| Side Effects | Joint pain, water retention, carpal tunnel syndrome, potential insulin resistance, and acromegaly features with long-term high doses. | Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity. | Injection site soreness, potential hypoglycemia, and localized swelling. Generally well-tolerated. |
| Best For |
What They Have in Common
Human Growth Hormone (HGH), MK-677 (Ibutamoren), PEG-MGF are all commonly used for:
Key Differences
Unique to Human Growth Hormone (HGH):
Unique to MK-677 (Ibutamoren):
Detailed Analysis
Commonalities
Both Human Growth Hormone (HGH) and MK-677 (Ibutamoren) are commonly used for Muscle Growth, Fat Loss, Recovery & Healing, Sleep Quality.
Which Should You Choose?
Human Growth Hormone (HGH) has stronger evidence for Fat Loss, Recovery & Healing. MK-677 (Ibutamoren) has stronger evidence for Sleep Quality.
Commonalities
Both Human Growth Hormone (HGH) and PEG-MGF are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
Human Growth Hormone (HGH) has stronger evidence for Muscle Growth, Recovery & Healing.
Commonalities
Both MK-677 (Ibutamoren) and PEG-MGF are commonly used for Muscle Growth, Recovery & Healing.
Which Should You Choose?
MK-677 (Ibutamoren) has stronger evidence for Muscle Growth.