Reviewed by the PeptideMind Team · Updated July 28, 2026
Melanotan 1 vs Melanotan 2:
Key differences comparison
The main difference between Melanotan I and Melanotan II is selectivity: Melanotan I targets one receptor and builds pigment only, while Melanotan II targets several, which is also why it's linked to appetite and libido effects. Melanotan II tans faster; Melanotan I has milder side effects.
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What Is Melanotan I?
Melanotan I (also known as afamelanotide) is a lab-made copy of a hormone your body already makes to control skin pigment. It's built to work on just one target, the skin's pigment switch, and its medical version is FDA-approved for a rare sun-sensitivity condition.
A focused, one-target design
Melanotan I mainly flips on the skin's pigment switch, without needing sun exposure to kick it into gear.
What it's best known for
Helping people with a rare condition called EPP tolerate sunlight without pain, by building up pigment as a kind of protection.
Where it stands legally
The medical version, afamelanotide (Scenesse), is FDA-approved for EPP. The research-grade Melanotan I sold online is not approved for human use and is labeled for research only.
What Is Melanotan II?
Melanotan II (MT-2) is a shorter version of the same hormone copy, but it's less picky about where it acts in the body. That broader reach is why it's studied for tanning, and also for effects on appetite and sex drive.
A broader, less-targeted design
Instead of hitting just one switch like Melanotan I, MT-2 flips on several related switches around the body, not only the one for skin pigment.
What it's best known for
Tanning is the main draw, but early research has also looked at its effects on sexual arousal and appetite, side effects of that broader reach.
Where it stands legally
Not FDA-approved for any use, including tanning. It's sold online as an unregulated research chemical, strictly for research purposes, not for people to use on themselves.
Melanotan 1 vs Melanotan 2 at a Glance
A side-by-side look at how Melanotan I and Melanotan II differ in how they work, how they're dosed, and where each stands legally.
Melanotan I
Read the full profile- What it targets (One pigment switch (focused))
- Peptide size/shape (Longer, straight-chain)
- Molecular weight (1,646.85 Da)
- Typical starting dose (0.25–0.5 mg/day)
- Typical upkeep dose (2–3x weekly)
- How long it lasts in the body (~0.5 hours)
- Given as a shot under the skin
- FDA-approved (as afamelanotide/Scenesse)
- Gentler, more limited side effects
Melanotan II
Read the full profile- What it targets (Several switches (broad))
- Peptide size/shape (Shorter, ring-shaped)
- Molecular weight (1,024.18 Da)
- Also affects appetite/libido
- Typical starting dose (0.25–0.5 mg/day)
- Typical upkeep dose (1–2x weekly)
- How long it lasts in the body (~1.5 hours)
- Given as a shot under the skin
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Comparison at a Glance: Melanotan I vs Melanotan II
A quick side-by-side look at how Melanotan I and Melanotan II differ in what they target in the body, how they tan, and where each stands legally.
How targeted each one is
Melanotan I sticks to the one switch that controls skin pigment. Melanotan II is less selective, also reaching switches tied to appetite and libido elsewhere in the body.
Tanning effect
Melanotan II tends to darken skin faster, using less total product. Melanotan I works slower, giving a more gradual, even tan over time.
Effects beyond tanning
Melanotan II is linked to reduced appetite and increased sexual arousal as side effects of its broader reach. Melanotan I's effects stay mostly limited to pigment.
Legal status
Melanotan I's medical version, afamelanotide (Scenesse), is FDA-approved for a rare condition called EPP. Melanotan II has no FDA approval for anything.
Melanotan I Dosage Guide for Skin & UV ProtectionMelanotan I Dosage Calculator
Melanotan I helps your skin tan and offers some UV protection, with fewer side effects than Melanotan II. People usually use it daily until they get the tan they want, then use it less often to maintain it.
Vial size
10 mg
Bacteriostatic water
3 mL
Dosing
250–500 mcg
Frequency
Daily
Cycle
2–4 weeks
Benefit
Skin & UV Protection
Melanotan II Dosage Guide for Skin & Sexual HealthMelanotan II Dosage Calculator
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 a couple of times a week to maintain it.
Vial size
10 mg
Bacteriostatic water
3 mL
Dosing
250–500 mcg
Frequency
Daily
Cycle
2–4 weeks
Benefit
Skin & Sexual Health
Melanotan I vs II: Which One Should You Research?
Unlike BPC-157 and TB-500, Melanotan I and II aren't usually combined. They're two different ways of reaching the same goal, and the choice mostly comes down to whether the research calls for a narrow effect or a broader one.
If you only want pigment effects
Melanotan I sticks to one target, which keeps it focused on pigment and gives it a milder reported side-effect profile than Melanotan II.
If faster tanning is the priority
Melanotan II is reported to darken skin faster and with less product used overall, but that comes with a broader, more varied set of reported side effects.
Neither is an approved cosmetic product
Only afamelanotide (Scenesse), Melanotan I's medical version, is FDA-approved, and only for EPP. Research-grade versions of both peptides are sold strictly for research, not for people to use on themselves.
Frequently Asked Questions: Melanotan I vs Melanotan II
Straight answers on how Melanotan I and Melanotan II compare, and how each is dosed. For research reference only.
Melanotan I vs II: Dosing Basics
Both peptides are typically dosed with a starting phase to build up pigment, followed by a less frequent upkeep phase, but the timing and amounts differ between the two.
Melanotan I starting phase
Commonly discussed at roughly 0.25–0.5 mg injected once a day for one to two weeks, before tapering down to an upkeep schedule.
Melanotan II starting phase
Commonly discussed at roughly 0.25–1 mg injected daily, often based on body weight, before tapering to just one or two doses a week.
Use a peptide-specific calculator
How concentrated the vial is and how much liquid you mix in changes the actual draw for both peptides. Use a dosage calculator to get an exact number instead of guessing from a general range.
Tanning Timeline: What to Expect Week by Week
Timelines vary by person, dose, and which peptide is used, but many research write-ups describe a similar general pattern for both.
Days 1 to 7
The skin is reported to start building pigment within about 48 hours of the first dose, with visible darkening typically showing up three to seven days in.
Weeks 2 to 6
Pigmentation is commonly described as building steadily over this window, with the deepest color reported around four to six weeks of continued use.
After stopping
The color is reported to gradually fade over the following weeks, similar to how a natural tan fades, with many people describing occasional upkeep doses to keep it going.
Free Downloadable Peptide Dosage Cheat Sheets
Reference dosage data for 100+ peptides is pre-loaded in these free cheat sheets, including common research stacks like the wolverine stack (BPC-157 + TB-500), MOTS-C, Retatrutide, and Semaglutide. Select a cheat sheet to see reference dose ranges, dosing frequency, and half-life for every peptide it covers. For research purposes only.
