MK-677 (Ibutamoren) vs Oxytocin
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
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 →Oxytocin
Oxytocin is a natural hormone produced in the hypothalamus, often called the 'love hormone' or 'bonding hormone.' It plays key roles in social bonding, childbirth, lactation, and stress regulation.
Full details →Side-by-Side Comparison
| Aspect | MK-677 (Ibutamoren) | Oxytocin |
|---|---|---|
| Dose Range | 10 mg–25 mg | 24 mcg–48 mcg |
| Frequency | 1x daily | 1x daily |
| Cycle Length | 8–24 weeks | 2–4 weeks |
| Route | oral | intranasal |
| Mechanism | 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 oxytocin receptors in the brain and peripheral tissues. Promotes social bonding, reduces anxiety and stress response, and has various peripheral effects on smooth muscle contraction. |
| Typical Dosage | Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase. | Intranasal: 20-40 IU (international units) for social/anxiolytic effects. Clinical uses (labor induction) require IV administration under medical supervision. |
| Administration | Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing. | Intranasal spray for behavioral effects. IV only in clinical settings. Sublingual also possible. Best used situationally rather than continuously. |
| Side Effects | Increased appetite and water retention are most common. May cause lethargy, vivid dreams, and mild numbness. Can affect blood glucose and insulin sensitivity. | Intranasal: headache, nasal irritation, drowsiness. May cause over-attachment or emotional sensitivity. IV (clinical): uterine hyperstimulation, water retention. |
| Best For |
What They Have in Common
MK-677 (Ibutamoren), Oxytocin are both commonly used for:
Key Differences
Unique to MK-677 (Ibutamoren):
Unique to Oxytocin:
Which Has Stronger Evidence?
- Sleep Quality: MK-677 (Ibutamoren) has stronger research support.
| Goal | MK-677 (Ibutamoren) | Oxytocin |
|---|---|---|
| Sleep Quality | high | low |
Key Studies
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
Oxytocin
- Oxytocin promotes socially triggered cataplexy.
Nature neuroscience, 2026
- Oxytocin induces embryonic diapause.
Science advances, 2025
- Oxytocin and the microbiome.
Comprehensive psychoneuroendocrinology, 2023
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