Human Growth Hormone (HGH) vs MK-677 (Ibutamoren)
A detailed comparison to help you understand the differences and choose 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 →Side-by-Side Comparison
| Aspect | Human Growth Hormone (HGH) | MK-677 (Ibutamoren) |
|---|---|---|
| Dose Range | 200 mcg–2 mg | 10 mg–25 mg |
| Frequency | 1x daily | 1x daily |
| Cycle Length | 12–24 weeks | 8–24 weeks |
| Route | subcutaneous | oral |
| 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. |
| 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. |
| 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. |
| 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. |
| Best For |
What They Have in Common
Human Growth Hormone (HGH), MK-677 (Ibutamoren) are both commonly used for:
Key Differences
Unique to Human Growth Hormone (HGH):
Which Has Stronger Evidence?
- Fat Loss: Human Growth Hormone (HGH) has stronger research support.
- Recovery & Healing: Human Growth Hormone (HGH) has stronger research support.
- Sleep Quality: MK-677 (Ibutamoren) has stronger research support.
| Goal | Human Growth Hormone (HGH) | MK-677 (Ibutamoren) |
|---|---|---|
| Muscle Growth | high | high |
| Fat Loss | high | medium |
| Recovery & Healing | high | medium |
| Sleep Quality | medium | high |
Key Studies
Human Growth Hormone (HGH)
- Transgenic Artifacts Caused by Passenger Human Growth Hormone.
Trends in endocrinology and metabolism: TEM, 2018
- [Human growth hormone and Turner syndrome].
Anales de pediatria (Barcelona, Spain : 2003), 2017
- Significance of the disulphide bonds of human growth hormone.
Endokrynologia Polska, 2013
MK-677 (Ibutamoren)
- Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: II. Case example with ibutamoren (MK-677), a growth hormone secretagogue.
Clinica chimica acta; international journal of clinical chemistry, 2026
- Hepatotoxicity induced by MK-677.
BMJ case reports, 2025
- Investigating the P53-dependent anti-cancer effect of ibutamoren in human cancer cell lines.
Basic & clinical pharmacology & toxicology, 2025
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