Melanotan II

Mechanism, Dosing, Effects

Melanotan II is a synthetic analog of α-melanocyte-stimulating hormone (α-MSH). It is primarily studied for its ability to increase skin pigmentation (tanning) and is also known to stimulate libido and erectile activity as secondary effects. It activates melanocortin receptors, leading to melanin production in the skin.

Mechanism of Action

Melanotan II works by:

Activating MC1R receptors in melanocytes
Increasing melanin production
Enhancing UV-independent tanning
Stimulating MC3R & MC4R receptors (linked to libido & appetite control)
Increasing cAMP signaling → pigment synthesis

This leads to progressive skin darkening even with minimal sun exposure.

Dosing Strategy

Route: Subcutaneous
Vial: 10 mg

Reconstitution

Add 3.0 mL bacteriostatic water
Concentration: 3.33 mg/mL
Syringe reference:
- 1 unit = 33.3 mcg

Standard Titration Protocol

Loading Phase

Week 1
→ 250 mcg daily
→ 7.5 units (0.075 mL)

Week 2
→ 500 mcg daily
→ 15 units (0.15 mL)

Week 3
→ 750 mcg daily
→ 22.5 units (0.225 mL)

Weeks 4–8
→ 1000 mcg daily
→ 30 units (0.30 mL)

Maintenance Phase

After pigmentation achieved:

→ 500–1000 mcg
→ 1–2× per week

Cycle Length

Loading: 6–8 weeks
Maintenance: As needed

Effects and Outcomes

Commonly observed:

Progressive skin tanning
Reduced sunburn risk
Increased libido
Possible spontaneous erections
Appetite suppression (mild)
Freckle darkening
Long-lasting pigmentation

Safety and Tolerability

Common side effects

Nausea
Facial flushing
Yawning
Mild fatigue
Increased libido

Less common

Temporary darkening of moles/freckles
Injection-site irritation

Safety Notes

Start low dose to reduce nausea
Do NOT exceed recommended dosing
Rotate injection sites
Not FDA-approved
Avoid excessive UV exposure
Monitor moles for changes

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