Melanotan II vs MK-677 (Ibutamoren)

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

Melanotan II

Melanotan II is a synthetic peptide analog of α-MSH with broader receptor activity than Melanotan I. It produces tanning effects and has notable effects on sexual function and appetite suppression.

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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.

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Side-by-Side Comparison

AspectMelanotan IIMK-677 (Ibutamoren)
MechanismNon-selective melanocortin receptor agonist affecting MC1R (tanning), MC3R and MC4R (sexual function and appetite). This broader activity explains its multiple effects beyond tanning.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 DosageTypical protocols: 0.25-0.5mg daily during loading phase for 1-2 weeks, then 0.5-1mg before UV exposure for maintenance. Start low to assess tolerance.Typical dosing: 10-25mg taken orally once daily. Often taken at night due to sleep benefits and appetite increase.
AdministrationSubcutaneous injection. Usually combined with UV exposure for tanning effects. Nasal spray formulations exist but have lower bioavailability.Oral administration (capsule or liquid). Can be taken with or without food. Long half-life allows once-daily dosing.
Side EffectsNausea (common initially), facial flushing, spontaneous erections, increased libido, appetite suppression, and mole darkening.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

Both Melanotan II and MK-677 (Ibutamoren) are commonly used for:

Key Differences

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