A synthetic copy of the hormone that switches on tanning. Small human trials found it darkened skin without sun exposure and triggered erections in men with erectile dysfunction. It has never been approved by any regulator.
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Subcutaneous
Route
3 recommended
Sites
Once daily
Frequency
Preparation
Bacteriostatic water (BAC water)—the preservative allows multiple uses
Insulin syringes (29-31 gauge) for precise dosing
Alcohol swabs for sterilization
Your Melanotan-2 powder vial (typically 10mg)
Pro tip
Prepare all supplies on a clean surface before you begin. Having everything ready makes the process smoother and more sterile.
Mixing
Wash your hands thoroughly with soap and water. Gather all supplies on a clean, flat surface.
Remove the plastic cap from the peptide vial and wipe the rubber stopper with an alcohol swab. Let it air dry.
Draw the appropriate amount of bacteriostatic water into a sterile syringe.
Insert the needle into the vial at an angle, aiming at the inside wall of the vial. Slowly push the plunger to let the water trickle down the glass wall -- do NOT squirt directly onto the powder.
Once all water is added, gently swirl the vial in a slow circular motion. Never shake the vial, as this can damage the peptide bonds.
Continue swirling until the powder is completely dissolved and the solution is clear. If particles remain, let the vial sit for a few minutes and swirl again.
Label the vial with the date of reconstitution, the peptide name, and the concentration (e.g. 250mcg per 0.1mL).
Example calculation
If you have a 10mg vial and add 2mL of BAC water, you get a concentration of 5mg/mL (or 5000mcg/mL). So every 0.1mL (10 units on an insulin syringe) equals 500mcg of MT-2.
Dose calculation
For a 250mcg dose at 5mg/mL concentration: draw 0.05mL (5 units on a standard insulin syringe). For 500mcg: draw 0.1mL (10 units). Many users add 2mL to a 10mg vial for easy math.
Pro tip
Always add the bacteriostatic water slowly, letting it run down the side of the vial. Never shake the vial -- swirl gently to avoid damaging the peptide.
Location
Site 01
Abdomen
Pinch the skin 2 inches from navel. Avoid the area directly around the belly button. Rotate between left and right sides.
Site 02
Outer Thigh
Middle third of the outer thigh. Keep at least 4 inches above the knee and below the hip. Alternate legs each injection.
Site 03
Upper Arm
Back or outer area of the upper arm. This site may require assistance from another person for proper technique.
Rotate between 3 sites to prevent tissue buildup and ensure consistent absorption.
Pro tip
Rotate your injection sites with each dose to prevent lipohypertrophy (buildup of fatty tissue). Keep a simple log of where you last injected.
Step by step
Wash your hands thoroughly with soap and water
Clean the injection site with an alcohol swab and let it dry
Pinch about an inch of skin to create a fold
Insert the needle at a 45-90 degree angle
Inject slowly and steadily—rushing can increase nausea
Wait 5-10 seconds before removing the needle
Don't rub the site—just light pressure if needed
Pro tip
This peptide uses subcutaneous injection (just under the skin)—this is the most common and effective method for mt-2. Inject at a 45-90 degree angle into pinched skin. Aspirate before injecting to ensure you haven't hit a blood vessel.
Timing
Optimal timing
Best time
Evening or before bed works best for most people. This helps you sleep through any initial nausea or flushing. The long half-life (33+ hours) means timing isn't critical for effectiveness.
With food?
Taking MT-2 on an empty stomach speeds absorption but may increase nausea. If nausea is an issue, try a light snack 30-60 minutes before. Once you're past the first week, food timing matters less.
Stacking notes
If using with other peptides, inject at different sites. MT-2 is often the only peptide people use at bedtime due to the drowsiness it can cause. Don't combine with PT-141 on the same day—both affect the same receptors [19].
Sample daily schedule
Evening (before bed)
250-500 mcg during loading phase injection
Site: Rotate between belly, thigh, and arm
Evening dosing helps you sleep through nausea and flushing. During loading (first 2-3 weeks), dose daily. Get 10-20 minutes of UV exposure every few days to activate the melanin your body is producing.
Evening (1-3 times per week)
250-500 mcg for maintenance injection
Site: Rotate injection sites
Once you've reached your desired tan, switch to maintenance dosing. The long half-life means 2-3 doses per week usually maintains color. Brief UV exposure (even just sunlight) helps maintain the tan.
Dosing tiers
Dose
0.25 mg (250 mcg)
Frequency
Once daily
Duration
First 3-5 days (loading)
Community-reported starting dose, not peer-reviewed. No clinical trial used a flat 0.25 mg dose. The published human trials dosed by body weight at 0.01-0.03 mg/kg subcutaneously in 3 healthy men [1]. Mild nausea was reported at most dose levels in that trial, which is what starting low is commonly described as managing [1].
Dose
0.5 mg (500 mcg)
Frequency
Once daily
Duration
Continue loading 7-14 days until desired pigmentation
Community-reported loading dose, not peer-reviewed. The dose used in every published human trial was 0.025 mg/kg subcutaneously, about 1.75 mg for a 70 kg adult, given to 3 healthy men [1] and to 20 men with erectile dysfunction [4][6][7]. Subcutaneous is the only route with human trial evidence [1]. In the phase-I trial, 0.03 mg/kg produced grade II drowsiness and fatigue in 1 of 2 men who reached that dose, which is why 0.025 mg/kg was the dose carried forward [1].
Dose
0.5 mg (500 mcg)
Frequency
2-3 times per week
Duration
Ongoing maintenance
Community-reported maintenance schedule, not peer-reviewed. No published trial tested a maintenance phase; the longest published human dosing was 10 subcutaneous doses over 2 weeks in 3 healthy men [1]. A systemic-toxicity case followed a 6 mg self-injection, roughly three times the 0.025 mg/kg dose used in trials [9].
Preservation
Before mixing
Store your MT-2 powder in the refrigerator (36-46°F / 2-8°C) for up to 12 months or in the freezer (-4°F / -20°C) for up to 2 years. Keep in original sealed vial away from light. The powder is quite stable when stored properly.
After mixing
Refrigerate at 36-46°F (2-8°C) immediately after mixing. Never freeze reconstituted MT-2—it will be destroyed. Keep away from light and use within 28-30 days for best potency.
Shelf life after mixing
28-30 days
Signs of degradation
Discard the vial immediately if you notice any of these:
Cloudy or hazy solution (should be crystal clear)
Visible particles or floaters in the solution
Any color change—solution should be colorless
Reduced effectiveness (if your tan is fading faster than usual)
Important
When to stop
Any mole shows concerning changes (growth, irregular borders, color changes, bleeding)
You develop new moles that appear atypical or concerning
Nausea or flushing remains severe beyond the first week
You experience priapism or prolonged erection
Any signs of allergic reaction (difficulty breathing, significant swelling)
You've achieved your desired tan and completed your cycle
Melanotan-2 is not FDA approved and is considered a research compound. The long-term effects on skin cancer risk are not definitively known. Regular dermatological monitoring is essential for anyone using MT-2. This information is educational only—consult a healthcare provider before use.
Clean technique checklist
Wash hands thoroughly with soap and water before handling supplies
Swab vial tops and injection site with alcohol and let dry
Never touch the needle tip or allow it to contact non-sterile surfaces
Use a new syringe and needle for each injection
Dispose of used sharps in a proper sharps container
Store reconstituted peptides according to the storage instructions above
Published research
Dorr RT, Lines R, Levine N, Brooks C, Xiang L, Hruby VJ, Hadley ME · 1996
Pilot phase-I human study: subcutaneous melanotan-II induced measurable skin tanning in healthy male volunteers after only 5 low doses (every other day), with pigmentation increasing in the face, upper body and buttocks. 0.025 mg/kg/day was recommended for subsequent phase-I work. Confirms MT-II induces UV-independent tanning in humans.
Sawyer TK, Sanfilippo PJ, Hruby VJ, Engel MH, Heward CB, Burnett JB, Hadley ME · 1980
The foundational research that led to MT-2 development showed that synthetic MSH analogs could be far more potent than natural hormones at stimulating melanin production. This work at the University of Arizona laid the groundwork for all tanning peptides.
Hadley ME, Dorr RT · 2006
This comprehensive review documented MT-2's effects on tanning, sexual function, and appetite across multiple studies. The authors noted its potential for treating various conditions while also highlighting the need for more long-term safety research.
Wessells H, Levine N, Hadley ME, Dorr R, Hruby V · 2000
Pooled human results from 20 men with psychogenic or organic erectile dysfunction, given melanotan-II subcutaneously in double-blind, placebo-controlled crossover studies. Erections occurred in 17 of the 20 men without any sexual stimulation, with a mean of 41 minutes of recorded tip rigidity above 80%. Increased sexual desire was reported after 13 of 19 melanotan-II doses (68%) versus 4 of 21 placebo doses (19%) (p<0.01). At the 0.025 mg/kg dose, severe nausea occurred in 12.9% of subjects.
Suzuki I, Im S, Tada A, Scott C, Akcali C, Davis MB, Barsh G, Hearing V, Abdel-Malek Z · 1999
Laboratory work in cultured human melanocytes (pigment-making skin cells): switching on the melanocortin-1 receptor raises cyclic AMP inside the cell, which is the main signal that starts melanin production. Treating human melanocytes with alpha-MSH increased eumelanin, the darker pigment. This is the receptor pathway melanotan-II acts on, though this study tested alpha-MSH and ultraviolet light rather than melanotan-II itself.
Wessells H, Fuciarelli K, Hansen J, Hadley ME, Hruby VJ, Dorr R, Levine N · 1998
Double-blind, placebo-controlled crossover trial in 10 men with erectile dysfunction of no known organic cause. Clinically apparent erections developed in 8 of the 10 men. Mean duration of tip rigidity above 80% was 38.0 minutes on melanotan-II versus 3.0 minutes on placebo (p=0.0045). Nausea, stretching and yawning, and decreased appetite were reported more often on melanotan-II than on placebo, but none required treatment. The dose was 0.025 mg/kg subcutaneously.
Wessells H, Gralnek D, Dorr R, Hruby VJ, Hadley ME, Levine N · 2000
Double-blind, placebo-controlled crossover in ten men with organic erectile dysfunction. MT-II 0.025 mg/kg subcutaneous produced RigiScan-recorded erections after 12 of 19 injections versus 1 of 21 placebo doses; mean rigidity score among responders was 6.9 of 10, and reported sexual desire was significantly higher than placebo.
Hjuler KF, Lorentzen HF · 2014
Case report: histologically confirmed cutaneous melanoma in a 20-year-old woman (Fitzpatrick type II) whose MT-II use in combination with tanning-bed exposure coincided with the lesion's development. One of several published reports of melanoma or eruptive atypical nevi arising during melanotropic peptide use.
Nelson ME, Bryant SM, Aks SE · 2012
Case report in one 39-year-old man: a 6 mg subcutaneous self-injection was followed by sympathomimetic toxicity (heart rate peaking at 146 beats per minute), rhabdomyolysis with creatine kinase rising to 17,773 IU/L, and kidney dysfunction (creatinine 2.25 mg/dL), requiring a three-day intensive-care admission. The report describes this as six times the starting dose the patient believed was recommended, and it is roughly three times the 0.025 mg/kg dose used in the clinical trials (about 1.75 mg for a 70 kg adult). The injected substance was confirmed as melanotan-II by mass spectrometry.
Mallory CW, Lopategui DM, Cordon BH · 2021
Case report: ischemic priapism after a 2 mg subcutaneous MT-II injection, refractory to maximal intracavernosal phenylephrine and requiring penoscrotal decompression. At least three peer-reviewed priapism cases after MT-II injection have been published (2013, 2019, 2021).
Yassin Alsabbagh A, Bhujel N, Singh RP · 2025
Case report in one 22-year-old woman who used a melanotan-II nasal spray for tanning and developed a mass in the upper front jaw. Tissue analysis confirmed mucosal malignant melanoma, a cancer of the moist lining of the mouth. She had surgery followed by ongoing immunotherapy. This is the only peer-reviewed report found on the nasal route, and it describes harm rather than effectiveness: no trial has tested melanotan-II as a nasal spray.
ClinicalTrials.gov registry record · 2026
Registered clinical trial, recruiting since 2 February 2026. This is a randomised, double-blind, placebo-controlled phase 2 study testing melanotan-II alongside narrowband UV-B light treatment in adults with stable nonsegmental vitiligo, a condition where patches of skin lose their colour. No results have been posted yet, so nothing about how well it works or how safe it is can be drawn from it. It is listed here because it is the only registered melanotan-II trial found on ClinicalTrials.gov.
Shand G; Oakley A (Chief Editor), DermNet · 2015
Dermatology reference page (DermNet, chief editor Dr Amanda Oakley, dermatologist; August 2015). States melanotan II is not approved for any medical condition and non-selectively mimics melanocortin peptides; stimulates eumelanin production, causing the skin to go darker; usually injected under the skin every second day, with tanning in trials within 5 doses. Short-term side effects after administration: facial flushing; reduced appetite, nausea and vomiting; in males, spontaneous erections 1-5 hours after administration with a yawning and stretching complex. Long-term concern about melanoma, deepening of the colour of moles, new moles and atypical melanocytic naevi, melanonychia, rhabdomyolysis and encephalopathy syndrome. Bremelanotide is a drug based on melanotan II; melanotan II has been shown to increase female sexual desire in patients with sexual arousal disorder. No evidence exists for use in pregnancy or breastfeeding and avoidance is recommended.
Peters B, Hadimeri H, Wahlberg R, Afghahi H · 2020
Case report with literature review (CEN Case Rep, full text PMC7148395). Melanotan II stimulates melanocytes via MC1-R to increase eumelanin production, resulting in sunless tanning; it acts across melanocortin receptor subtypes located in skin, brain, digestive tract, nervous system and glands, and the reported adverse effects relate to receptor location: nausea, abdominal pain, anxiety, flushing, dizziness, headaches, appetite suppression, stomach pain, cramping, severe constipation, spontaneous penile erections, muscle pain and induction of cancer in the skin. Describes a 45-year-old man with right-sided renal infarction after 27 mg of melanotan II over 6 months.
Habbema L, Halk AB, Neumann M, Bergman W · 2017
Review (Int J Dermatol). Unregulated melanotan I and II use is associated with cutaneous complications, particularly melanocytic changes in existing moles and newly emerging (dysplastic) nevi; four case reports describe melanomas emerging from existing moles during or shortly after melanotan use, although conclusive evidence linking these phenomena is lacking. Afamelanotide is the only alpha-MSH analogue approved, for a limited number of indications; multiple national health organizations have issued safety warnings about melanotan I and II. Read from the abstract; full text not open.
Moiz A, O'Keefe EL, O'Keefe JH · 2026
Review (Mo Med, full text PMC13585006). Melanotan-II is a cyclic synthetic alpha-MSH analogue marketed to cause skin darkening without UV exposure, increase libido and erectile function, and suppress appetite; a non-selective agonist at MC1R, MC3R, MC4R and MC5R. Chronic MC1R overstimulation has been clinically documented to cause rapid darkening of existing moles, development of atypical melanocytic nevi, and acute presentation of cutaneous melanoma; MC4R agonism stimulates the sympathetic nervous system, raising blood pressure and heart rate; rhabdomyolysis is described.
Resnick G, Khajeh-Afzaly M, Yousefian F, Raza A, Issa NT · 2026
Systematic review of sunless tanning agents (J Clin Aesthet Dermatol, full text PMC13016451). Melanotan is a synthetic alpha-MSH analogue; acting on MC1R it stimulates melanin production and tyrosinase activity, leading to melanocyte proliferation and skin hyperpigmentation. DHA self-tanners instead react with free amino acids in the stratum corneum, producing brown melanoidins. Case reports link melanotan to new or changing pigmented lesions, with causality unproven; priapism, renal infarction and rhabdomyolysis are reported.
Hadley ME · 2005
Review (Peptides). Melanotan II can enhance sexual function in human males (erectile activity) and females (increased levels of sexual desire and genital arousal); it works at the level of the brain. The sexual actions were discovered accidentally while studying skin pigmentation. Read from the abstract; full text not open.
Ückert S, Bannowsky A, Albrecht K, Kuczyk MA · 2014
Review (Expert Opin Investig Drugs) of the clinical development of melanocortin receptor agonists - melanotan I, melanotan II and bremelanotide - for female sexual arousal and orgasmic disorders and male erectile dysfunction, acting on the central melanocortin system. Read from the abstract; full text not open.
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