Melanotan II vs Melanotan I
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: MT-II, MT2
Melanotan II is a synthetic copy of alpha-melanocyte-stimulating hormone (alpha-MSH), nicknamed the tanning peptide because it darkens skin without much sun. It also triggers erections and can blunt appetite, which is why it became the template for the FDA-approved drug bremelanotide (PT-141). Melanotan II itself is not approved by the FDA or EMA and is sold only as an unregulated research chemical.
Also: Afamelanotide, Scenesse
Melanotan I is the research name for afamelanotide, a 13-amino-acid synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH), also written as [Nle4, D-Phe7]-alpha-MSH or NDP-MSH. It is the only melanocortin peptide with regulatory approval: sold as Scenesse, it was approved by the EMA in 2014 and the FDA in 2019 to increase pain-free light exposure in adults with erythropoietic protoporphyria (EPP). It is given as a 16 mg bioresorbable implant under the skin by a clinician, not as a tanning shortcut.
Key Comparison Insights
- Melanotan I is FDA approved, while Melanotan II remains in research stages.
- Melanotan II is categorized as Sexual Health, while Melanotan I is Skin & Hair.
- Melanotan I has stronger research evidence (FDA Approved) compared to Melanotan II (Limited Research).
Detailed Comparison
| Attribute | Melanotan II | Melanotan I |
|---|---|---|
| Category | Sexual Health | Skin & Hair |
| FDA Status | Not FDA Approved | FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | Melanotan II is a non-selective agonist of the melanocortin receptors, hitting MC1, MC3, MC4, and MC5. Switching on MC1 receptors in skin pigment cells ramps up melanin production, which is the tanning effect. Its sexual effects come from a completely different site: activating MC4 receptors in the brain triggers the neural circuits behind sexual arousal and desire, independent of the vascular plumbing that Viagra-type drugs target. Because it activates so many receptors at once rather than just one, it produces a broad spread of effects and side effects. | Afamelanotide binds and activates the melanocortin-1 receptor (MC1R) on pigment-producing melanocytes, driving production of eumelanin, the dark, photoprotective form of melanin. Two amino acid swaps from natural alpha-MSH - norleucine at position 4 and D-phenylalanine at position 7 - make it bind MC1R more tightly and resist breakdown, so it lasts far longer and acts more potently than the native hormone. The extra eumelanin absorbs and scatters light and also brings antioxidant and DNA-repair-supporting effects, which is why it raises the light dose EPP patients can tolerate before pain hits. Unlike Melanotan II, it is selective enough toward MC1R that it is not primarily a sexual-function or appetite agent. |
| Common Dosing | 250-500 mcg daily (loading), then 500-1,000 mcg weekly (maintenance) Daily during loading (1-2 weeks), then weekly maintenance | 500-1000 mcg daily (loading), then 500-1000 mcg 1-2x weekly (maintenance) Daily during loading (1-2 weeks), then 1-2x weekly maintenance |
| Administration | Subcutaneous injection | Subcutaneous implant (not injection) |
| Typical Duration | Loading phase 2-3 weeks, then maintenance | Long-term / as needed before sun season |
| Best Time to Take | Evening or before sun exposure | Evening or before sun exposure |
Possible Side Effects May vary by individual |
|
|
| Research Summary | Human evidence for Melanotan II is real but narrow and mostly old. A published clinical study in men with organic erectile dysfunction found that the alpha-MSH analog produced subjectively reported erections after 12 of 19 injections versus only 1 of 21 placebo doses, with longer periods of penile rigidity and increased sexual interest, alongside frequent nausea and yawning. That erectogenic finding is exactly what spun off bremelanotide as a regulated drug. The tanning use, by contrast, has no large safety trials behind it, and dermatology sources flag serious concerns: new or changing moles and melanoma reports, uneven or permanent darkening, nausea, and the obvious dangers of injecting an unregulated powder of uncertain purity. Bottom line: it clearly does something at the receptor level, but Melanotan II as sold is an unapproved compound with a thin safety record and known risks, distinct from its approved descendants afamelanotide and bremelanotide. | This is one of the few peptides on this list with gold-standard human evidence. The pivotal data came from two multicenter, randomized, double-blind, placebo-controlled trials published in the New England Journal of Medicine in 2015 (Langendonk et al., 373(1):48-59), enrolling 168 EPP patients across the EU and US who received the 16 mg implant or placebo every 60 days. Afamelanotide significantly increased pain-free time in sunlight (for example, median 69.4 vs 40.8 hours in the US trial), reduced phototoxic reactions, and improved disease-specific quality of life, with mostly mild adverse events. Long-term observational follow-up of EPP patients has supported continued benefit and an acceptable safety profile. The big caveats: this approval is narrowly for EPP, not for cosmetic tanning, and the unregulated injectable 'Melanotan' products people buy online are not the same controlled, clinician-administered implant and carry real risks. Bottom line: a genuinely proven, approved drug for a rare condition, frequently misused outside that lane. |
Frequently Asked Questions: Melanotan II vs Melanotan I
What is the difference between Melanotan II and Melanotan I?
Melanotan II is a sexual health peptide that melanotan ii is a synthetic copy of alpha-melanocyte-stimulating hormone (alpha-msh), nicknamed the tanning peptide because it darkens skin without much sun. it also triggers erections and can blunt appetite, which is why it became the template for the fda-approved drug bremelanotide (pt-141). melanotan ii itself is not approved by the fda or ema and is sold only as an unregulated research chemical. Melanotan I is a skin & hair peptide that melanotan i is the research name for afamelanotide, a 13-amino-acid synthetic analog of alpha-melanocyte-stimulating hormone (alpha-msh), also written as [nle4, d-phe7]-alpha-msh or ndp-msh. it is the only melanocortin peptide with regulatory approval: sold as scenesse, it was approved by the ema in 2014 and the fda in 2019 to increase pain-free light exposure in adults with erythropoietic protoporphyria (epp). it is given as a 16 mg bioresorbable implant under the skin by a clinician, not as a tanning shortcut. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Melanotan II or Melanotan I?
Neither is universally "better" - the choice depends on your specific goals. Melanotan II is typically used for sexual health purposes, while Melanotan I is used for skin & hair. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Melanotan II and Melanotan I be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Melanotan II and Melanotan I together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.