Melanotan II

Overview

Melanotan II (MT-2) is a synthetic analog of alpha-Melanocyte Stimulating Hormone (α-MSH) developed at the University of Arizona in the 1990s. Originally designed as a potential treatment for skin cancer prevention through UV-free tanning, it was found to have additional effects on sexual function and appetite.

MT-2 is a non-selective melanocortin receptor agonist, meaning it activates multiple melanocortin receptors (MC1R through MC5R), leading to its diverse effects.

Key Characteristics

• Origin: Synthetic α-MSH analog
• Classification: Non-selective melanocortin agonist
• Primary Effects: Tanning, sexual arousal, appetite suppression
• Receptors: MC1R (pigment), MC3R/MC4R (sexual/appetite), MC5R
• Half-Life: Long (33-36 hours)

Important Safety Note

Mechanism

Primary Mechanisms

1. MC1R Activation (Tanning)

Melanin production pathway:

• Binds to MC1R on melanocytes
• Activates adenylyl cyclase
• Increases cAMP
• Activates tyrosinase enzyme
• Produces eumelanin (brown/black pigment)

This creates a tan without UV exposure, though many users combine with minimal sun exposure for enhanced effect.

2. MC3R/MC4R Activation (Sexual)

Central nervous system effects:

• Activates hypothalamic receptors
• Increases dopamine in reward centers
• Creates psychological arousal
• Enhances sexual desire and function
• Effects in both men and women

This mechanism led to development of PT-141 (Bremelanotide).

3. MC4R (Appetite)

Appetite suppression:

• Hypothalamic appetite center modulation
• Reduced hunger signals
• Potential for weight management
• Can cause significant appetite loss initially

4. MC5R (Sebaceous Glands)

Skin effects:

• Modulates sebum production
• May affect skin oiliness
• Less studied mechanism

Research

Tanning Effects

Mechanism

• Increases melanin production
• Creates tan without UV exposure
• Most effective in those who can naturally tan (Fitzpatrick II-IV)
• Limited effect in very fair individuals (Fitzpatrick I)

Observations

• Darkening of skin occurs within days
• Effects most pronounced after several weeks
• Maintenance dosing keeps tan
• Tan fades gradually after discontinuation

Sexual Effects

Clinical Observations

• Enhanced erectile function in men
• Increased libido in both sexes
• Spontaneous erections reported
• Led to development of PT-141 for HSDD

Appetite Suppression

Weight Loss Potential

• Significant appetite reduction
• Reduced food seeking behavior
• May assist weight management
• Effect diminishes with continued use

Nevus (Mole) Changes

Important Safety Concern

• Can darken existing moles
• May cause new nevi to appear
• Irregular mole changes reported
• Requires dermatological monitoring

Dosing

Research Protocols (Reference Only)

Administration Notes

Subcutaneous Injection

• Standard route
• Inject into fatty tissue
• Rotate injection sites
• Most consistent absorption

Intranasal

• Alternative route
• Less consistent absorption
• May have reduced side effects
• Requires higher doses

Starting Protocol

• Begin with very low test dose (0.1 mg)
• Assess side effect tolerance
• Gradually increase if tolerated
• Nausea is common initially

Reconstitution

• Use bacteriostatic water
• Typical: 10mg vial + 2ml water = 5mg/ml
• Refrigerate after reconstitution
• Use within 4-6 weeks
• Protect from light

Side Effects & Risks

Common Side Effects

Very Common (>30%)

• Nausea (especially initially)
• Facial flushing
• Fatigue/yawning
• Spontaneous erections (men)

Common (10-30%)

• Appetite suppression
• Mole darkening
• Freckle darkening
• Injection site reactions

Less Common (1-10%)

• Headache
• Dizziness
• Stomach cramping
• Increased blood pressure

Serious Concerns

Melanoma Risk

• MT-2 promotes melanocyte activity
• Theoretical concern for melanoma stimulation
• MUST monitor all moles
• See dermatologist before and during use
• Discontinue if suspicious mole changes

Cardiovascular

• Can increase blood pressure
• May affect heart rate
• Use caution with cardiovascular disease
• Avoid in uncontrolled hypertension

Unpredictable Pigmentation

• Can cause uneven tanning
• May darken lips, gums, scars
• Darkening of genitals common
• Effects can be cosmetically concerning

Priapism Risk (Men)

• Prolonged erection possible
• Medical emergency if >4 hours
• Higher risk with PDE5 inhibitors
• Seek immediate medical attention

Contraindications

Absolute:

• History of melanoma
• Atypical mole syndrome
• Family history of melanoma
• Cardiovascular disease
• Pregnancy/breastfeeding

Relative:

• Many moles
• Fair skin (Fitzpatrick I)
• History of skin cancer
• Uncontrolled hypertension

Comparison: Melanotan II vs PT-141

Monitoring

Before Starting

• Dermatological examination
• Full-body mole mapping/photos
• Cardiovascular assessment
• Blood pressure measurement

During Use

• Monthly mole self-examination
• Blood pressure monitoring
• Report any mole changes immediately
• Photograph concerning areas

If Mole Changes Occur

• Discontinue immediately
• See dermatologist urgently
• Document all changes
• Do not resume without clearance

Regulatory

Current Status

Legal Considerations

• Not approved for human use anywhere
• Sold as "research chemical"
• Manufacture quality varies widely
• Use is entirely at own risk
• No pharmaceutical oversight

FDA Warning

The FDA has issued warnings about:

• Unknown long-term effects
• Melanoma promotion risk
• Variable product quality
• Serious potential side effects

References