Human Growth Hormone (HGH) vs MK-677 (Ibutamoren) vs SS-31 (Elamipretide)
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 →SS-31 (Elamipretide)
SS-31, also known as Elamipretide or Bendavia, is a mitochondria-targeted tetrapeptide. It has been studied extensively for mitochondrial diseases, heart failure, and age-related decline in mitochondrial function.
Full details →Side-by-Side Comparison
| Aspect | Human Growth Hormone (HGH) | MK-677 (Ibutamoren) | SS-31 (Elamipretide) |
|---|---|---|---|
| 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. | Concentrates in the inner mitochondrial membrane where it binds to cardiolipin, stabilizing electron transport chain function, reducing reactive oxygen species, and improving ATP production efficiency. |
| 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. | Clinical trials have used IV infusions of 0.25mg/kg for acute conditions. Subcutaneous dosing protocols for research use typically range from 1-5mg daily. |
| 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. | Can be administered IV or subcutaneously. Most clinical research has used IV administration for cardiac conditions. |
| 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. | Generally well-tolerated. Clinical trials reported injection site reactions and occasional headache. |
| Best For |
What They Have in Common
Human Growth Hormone (HGH), MK-677 (Ibutamoren), SS-31 (Elamipretide) are all commonly used for:
Key Differences
Unique to Human Growth Hormone (HGH):
Unique to MK-677 (Ibutamoren):
Unique to SS-31 (Elamipretide):
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 SS-31 (Elamipretide) are commonly used for Recovery & Healing, Anti-Aging & Longevity.
Which Should You Choose?
Human Growth Hormone (HGH) has stronger evidence for Recovery & Healing. SS-31 (Elamipretide) has stronger evidence for Anti-Aging & Longevity.
Commonalities
Both MK-677 (Ibutamoren) and SS-31 (Elamipretide) are commonly used for 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.