Library / Peptides / Sexual Health / Melanotan 2

Emerging evidence · Grade B

Melanotan 2

Melanotan II

Evidence

Emerging

Route

Subcutaneous injection

Frequency

Daily during loading (5-7 days), then 1-2x weekly maintenance

Mechanism.

Melanotan II is a synthetic cyclic peptide analogue of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts as a non-selective melanocortin receptor agonist. It stimulates melanogenesis (tanning) and has sexual arousal effects through MC3R and MC4R activation. It is not approved by any regulatory body for human use but is widely sold online and used illicitly for tanning and sexual enhancement.

Melanotan II is like a skeleton key that opens many different locks in your body at once -- it triggers tanning, sexual arousal, and appetite suppression because it activates a whole family of receptors rather than targeting just one. This broad action is what makes it powerful but also unpredictable.

Mechanism · technical

Melanotan II binds to multiple melanocortin receptors (MC1R through MC5R) with varying affinity. Activation of MC1R stimulates melanin production in melanocytes, causing skin darkening. Activation of MC3R and MC4R in the hypothalamus produces sexual arousal effects and appetite suppression. Its non-selective binding profile is responsible for both its wide range of effects and its broader side effect profile compared to more selective analogues like afamelanotide or bremelanotide.

Part 02 · Dosing & administration

How it's taken.

Values below describe how Melanotan 2 has been administered in published trials and labeling. Provided for educational purposes only — this is not medical advice and not instructions for self-administration. Consult your healthcare provider before making any health decision.

Standard dose

0.25-0.5 mg (loading), then 0.5-1 mg maintenance

Subcutaneous injection · Daily during loading (5-7 days), then 1-2x weekly maintenance

Duration

Cycles as desired for tanning

Non-selective melanocortin receptor agonist (MC1R-MC5R). NOT FDA-approved. Associated with serious safety concerns including melanoma risk, priapism, and cardiovascular effects. Banned by many regulatory agencies.

Need help with reconstitution?

Use the free peptide calculator for dilution, unit conversion, and injection volume.

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Part 03 · Safety

Side effects, rare serious events, who shouldn't.

Reported side effects

Nausea (very common, especially initially), facial flushing, fatigue, spontaneous penile erections, injection site reactions, and darkening of moles and freckles. More concerning reports include elevated blood pressure, priapism, and potential melanoma promotion (darkening and changing appearance of existing nevi makes surveillance difficult). Case reports of melanoma in Melanotan II users exist, though causation is unestablished.

Absolute · do not use

History of melanoma or dysplastic nevi

Personal or family history of skin cancer

Pregnancy or breastfeeding

Children under 18

Known hypersensitivity to Melanotan II or any component

Cardiovascular disease (may affect blood pressure)

Autoimmune conditions

Interactions

Antihypertensives

Melanotan II can affect blood pressure; may potentiate or oppose antihypertensive effects

Moderate

PDE5 inhibitors (sildenafil, tadalafil)

Additive effects on erectile function and blood pressure; risk of hypotension and priapism

Moderate

Other melanocortin agonists (PT-141, Melanotan 1)

Additive melanocortin receptor activation; increased adverse effect risk

Moderate

Photosensitizing drugs

Increased tanning response may mask or potentiate phototoxic reactions

Minor

Labs to monitor

Dermatological Exam (Full Body Skin Check)

Baseline and every 6 months

Non-selective melanocortin agonist — monitor moles/nevi

Blood Pressure

Baseline and regularly

Melanocortin system affects cardiovascular function

CMP (Comprehensive Metabolic Panel)

Baseline and every 3 months

Liver and kidney function

CBC with Differential

Baseline and every 3 months

General safety monitoring

Part 04 · Research log

Every study we cite.

Each study with its published finding and a plain-language note on limitations or funding.

2015

Melanotan II: a review of safety concerns

Case reports of melanoma, priapism, and rhabdomyolysis associated with Melanotan II use

Case reports and reviews; no controlled safety data

PMID 25867045 ↗

2000

Effects of Melanotan II on sexual function

MT-II initiated erections in men with ED via MC4R activation

Small RCT; proof of concept

PMID 10699621 ↗

Part 05 · Cost & access

Where you can get it.

Regulatory status

Not approved by the FDA, EMA, or any major regulatory body for any indication. Classified as an unregulated peptide in most countries. Banned by the TGA in Australia. Widely available through grey-market peptide suppliers. Multiple regulatory agencies have issued warnings against its use.

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Part 06 · Your appointment

Questions to bring.

What are the risks of using a non-selective melanocortin agonist versus selective ones?

Should I have a dermatological exam before and during use given mole-darkening risks?

What cardiovascular monitoring is advisable with Melanotan II?

Are there safer FDA-approved alternatives for my specific goal?