Reviewed by the PeptideMind Team · Updated August 5, 2026

Melanotan II (MT-2) Peptide Dosage Calculator, Benefits & Side Effects

Melanotan II (MT-2) peptide dosage calculator plus tanning and libido-boosting protocols, reconstitution tips, benefits, and side effects backed by clinical research.

Basic Dosage Calculator

Calculate peptide doses with our visual syringe guide.

Peptide per vial

Target research quantity

Bac water added

As seen on

Melanotan II Dosage Schedule

A short nightly loading phase builds your tan gradually to minimize nausea and flushing, then steps down to a couple of nights a week to maintain the color you've built.

Tan Building Then Maintenance Protocol

an ongoing run with no fixed end date with the dose increasing over time, focused on skin and hair.

Daily dosing

Taken daily at night, on an empty stomach.

150–300 mcg

Starts at 150 mcg and increases to 300 mcg over 2 phases as your body adjusts. Injected just under the skin in the abdomen or thigh.

Melanotan II triggers your skin to tan and offers some protection from UV rays by activating a pigment-producing pathway. People typically use it daily until they reach the tan they want, then cut back to once or twice a week to maintain it. Nausea and flushing are common early on, so many start at 100 to 250 mcg for the first few days and inject before bed on an empty stomach.

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What is Melanotan II?

Melanotan II is a lab-made peptide related to a natural skin-pigment hormone, but it acts more broadly across several hormone receptors in the body. It was originally created to help prevent skin cancer by darkening skin without needing sun exposure, but researchers also noticed it affects sexual desire, leading to studies on its use for low libido and sexual arousal issues. It's used both in formal research and by people self-administering it for tanning or sexual enhancement effects.

Skin

Research targets include collagen production, skin elasticity, and hair follicle health.

Sexual

Research targets include libido, reproductive hormone signaling, and sexual function.

Skin

MT-2

Sexual

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What Does Melanotan II Do?

It attaches loosely to several related pigment-and-appetite receptors throughout the body rather than just one, switching on the same internal signal in each case. One receptor drives skin darkening, while another, active in the brain, affects sexual arousal and appetite.

Loosely binds several receptors

Attaches to multiple related pigment-and-appetite receptors, not just one.

Darkens skin

One receptor drives skin pigmentation.

Affects arousal & appetite

Another, active in the brain, affects sexual arousal and appetite.

Frequently Asked Questions About Melanotan II

Straight answers on reconstitution, dosing, and safety, everything you need to research with confidence. For research reference only.

Melanotan II (MT-2) is a synthetic, cyclic 7-amino-acid peptide originally developed at the University of Arizona in the late 1980s as a non-selective melanocortin receptor agonist. It binds to melanocortin receptors (primarily MC1R and MC4R), stimulating melanocytes to produce more melanin, which darkens the skin. Because it also acts on MC4R in the central nervous system, it has additional reported effects on appetite and sexual arousal beyond pigmentation.

Sources discussing self-directed use describe a 'loading phase' of roughly 0.25-1 mg injected subcutaneously daily (often based on ~0.025 mg/kg), followed by a lower maintenance dose taken 1-2 times per week once the desired pigmentation is reached. Starting at the low end of this range is commonly recommended to reduce nausea and other loading-phase side effects. These are conventions reported by vendors and user communities, not an approved clinical dosing standard, since Melanotan II has no established medical dosage.

Reported timelines suggest melanogenesis begins within about 48 hours of the first dose, but visible darkening typically takes 3-7 days to appear as new melanin migrates to the skin's surface, with peak pigmentation around 4-6 weeks of continued use. A tan built up this way is generally described as fading over 4-8 weeks after stopping, and some incidental or intentional UV exposure during use is commonly reported to accelerate and deepen the effect.

The most frequently reported side effect is nausea, especially during the initial loading phase, often starting 10-30 minutes after injection. Other commonly reported effects include vomiting, yawning, flushing, headache, reduced appetite, fatigue, and spontaneous or prolonged erections in men. Darkening or changes in existing moles and the appearance of new nevi have also been documented, which is a specific safety concern given melanocyte stimulation occurs throughout the body, not just in sun-exposed skin.

Yes, this is one of the most cited safety concerns. Because MT-2 stimulates melanocyte activity systemically, case reports and dermatology literature describe darkening, changes in shape or size, and new growth of moles/nevi during use, including reports involving melanoma in some individuals with a history of MT-2 use. Dermatology sources generally advise against use for this reason and recommend regular skin checks by a professional for anyone with a personal or family history of skin cancer or atypical moles who has used it.

Melanotan II has never been approved by the FDA (or equivalent regulators elsewhere) for any use, including tanning or sexual enhancement. It is not classified as a controlled substance in the US, but it also cannot be legally marketed or sold as a drug, supplement, or cosmetic for human use. In practice it is sold online as an unregulated 'research chemical,' and the FDA has issued warning letters and taken enforcement action against sellers marketing it for personal/human use. Regulations vary by country, so local laws should be checked.

PT-141 (bremelanotide) is a related melanocortin peptide developed from Melanotan II after researchers observed that MT-2 reliably triggered increased sexual arousal and spontaneous erections in trial subjects, alongside its tanning effect. PT-141 was engineered to emphasize those sexual-desire effects while reducing the pigmentation (tanning) activity. Unlike Melanotan II, bremelanotide (as Vyleesi) has received FDA approval, specifically for hypoactive sexual desire disorder in premenopausal women, making it the more clinically studied and regulated of the two.

As commonly described for peptides of this type, lyophilized (freeze-dried) Melanotan II is typically reconstituted with bacteriostatic water; the resulting solution should be clear and colorless, since cloudiness can indicate degradation. Unreconstituted powder is generally reported to be stable for extended periods when kept frozen (around -20°C or colder) and protected from light. Once reconstituted, sources commonly suggest refrigeration (2-8°C) and use within roughly 1-4 weeks, as stability declines over time in liquid form. Because Melanotan II is not an approved pharmaceutical product, there is no standardized, regulator-verified storage protocol, and any use is for research purposes only, not for human administration.

Melanotan II Reconstitution Guide

Melanotan II is supplied as a freeze-dried powder that must be mixed into a injectable solution before use. Available in 2mg, 10mg sizes.

10 mg lyophilized vial

Melanotan II is supplied as a freeze-dried powder that must be mixed into a injectable solution before use. Available in 2mg, 10mg sizes.

3 mL bacteriostatic water

Adding 3 mL of bac water to a 10 mg vial gives a workable concentration for syringe dosing. More water makes microdosing easier; less concentrates each draw.

Storage after mixing

Freeze the dry powder for up to two years, or it can sit at room temperature for a few weeks. Once mixed with liquid, refrigerate and use within two weeks, avoiding repeated freezing and thawing. After reconstitution, keep the vial refrigerated and use within 30 days.

Reconstitution steps

Remove caps & sanitize stoppers

Attach needle to syringe

Draw 3 mL bacteriostatic water

Insert needle into Melanotan II vial

Release water gently down the side

Swirl to dissolve — don't shake

Check for full dissolution

Refrigerate Melanotan II — good for 30 days

Chemical Makeup

Amino Acids

Melanotan II

Position 1

Asp

Position 2

His

Position 3

Phe

Position 4

Arg

Position 5

Trp

Position 6

Lys

Position 7

Amino acid sequence

?Position 1

Aspartic acidPosition 2

HistidinePosition 3

PhenylalaninePosition 4

ArgininePosition 5

TryptophanPosition 6

LysinePosition 7

What Are the Benefits of Melanotan II?

What research says it may help with, and how it works in the body.

skin health

: Triggers the skin's own pigment production to create a tan without needing sun exposure.
: More skin pigment acts like natural sun protection against sun damage.
: May help with certain skin conditions involving uneven or abnormal pigment.

sexual health

: In studies on erectile dysfunction caused by psychological factors, 80% of participants responded positively.
: In clinical trials, 73% of women reported feeling arousal within 24 hours.
: Increases sexual desire in both men and women by activating a receptor in the brain that governs arousal.

metabolic

: Activates a receptor in a brain region that controls hunger, reducing appetite by about 15% in studies.
: Increases fat burning by switching on the body's fat-metabolizing processes.

What Are the Side Effects of Melanotan II?

Who should avoid it, warning signs to watch for, and what to know before combining it with other compounds.

Who Should Avoid It

: History of melanoma or dysplastic nevi
: Pregnancy or breastfeeding
: Cardiovascular conditions
: Uncontrolled hypertension

Stop Right Away If You Notice

: Severe persistent nausea or vomiting
: Chest pain or significant blood pressure elevation
: Mole changes (size, shape, color) - monitor closely
: Prolonged painful erections (priapism)
: Severe headaches or vision changes
: Allergic reactions (rash, swelling, breathing difficulty)

Milder Signs to Watch For

Brown or dark powder indicates oxidation/impuritiesCloudy solution after mixing indicates degradation/contamination

Was it helpful?Yes

Is Melanotan II FDA approved?

Melanotan II is not an FDA-approved drug. It is intended for research purposes only and is not approved for human consumption, diagnostic, or therapeutic use.

Research Use Only

Melanotan II has not been evaluated by the FDA for safety or efficacy in humans.

No Clinical Oversight

Not manufactured under FDA-regulated quality or clinical standards.

Unregulated Sourcing

Purity, dosing, and sourcing are not verified through FDA testing or oversight.

A smartphone screen displaying FDA status for a drug, indicating "FDA approved drug: No" and "Classification: Research use only." A banner notes "Research Only" with the disclaimer "not for human use," emphasizing its intended use for laboratory and analytical purposes.

Melanotan II Cycle Length: How Long Should It Last?

This breaks down how long a typical Melanotan II cycle runs and what research suggests happens at each stage. Research shows that staying on a peptide continuously, without a break, may make it less effective over time.

That's why most research protocols build in a break between cycles, often called a washout period, to let the body reset before starting again.

Day 1-3: Possible nausea, flushing, fatigue
Day 3-7: Increased spontaneous erections (men), enhanced arousal
Week 1-2: Noticeable skin darkening, reduced appetite
Week 2-4: Significant tanning, stabilized sexual effects
Week 0-0: Maintained tan with less frequent dosing

Melanotan II Research References

It is a preclinical compound

3Research references

Melanotan II

Melanotan II is a preclinical compound

Melanogenesis & UV Protection Study

0.16mg/kg daily for 10 days increased eumelanin and achieved natural tan without UV exposure.

1999

Female Sexual Arousal Disorder Trial

Single dose of 0.025mg/kg resulted in 73% of premenopausal women reporting arousal within 24 hours.

2004

Erectile Dysfunction Phase II Trial

0.025mg/kg dose achieved 80% response rate with significant improvement in psychogenic ED over 3 months.

2000

Browse user-created protocols

Real protocols from the community that include Melanotan II

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Dr. JRSW

250days

6 peptides·Healing·1mo ago

Jana

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Melanotan II Comparisons

Skin

MT-1

Skin

MT-2

Sexual

Melanotan 1 vs Melanotan 2: Key differences comparison

Melanotan I is selective for MC1R and stays focused on pigment. Melanotan II activates multiple melanocortin receptors, driving broader effects on appetite and sexual response. Here's how MT-1 and MT-2 compare.

Melanotan II (MT-2) Peptide Dosage Calculator, Benefits & Side Effects

Melanotan II Dosage Schedule