Quick facts
Kinds of source describe where information comes from, not how good it is.
| Fact | MT-I | MT-II |
|---|---|---|
| Why people look at it | MT-IMainly tanning and pigment. Many are people who want color without the other effects linked to MT-II. | MT-IIMainly a faster, darker tan. Some also notice, and a few want, its effects on sex drive and appetite. |
| Kinds of source | MT-I
| MT-II
|
Side by side
MT-I is Melanotan-1. MT-II is Melanotan-2. They are separate compounds with their own pages.
What it is
- MT-I
- A peptide that leads the skin to make more pigment. It is the same core peptide as the medicine afamelanotide.
- MT-II
- A separate peptide from MT-I. People discuss it for tanning along with effects on appetite and sex drive.
Why people look at it
- MT-I
- Mainly tanning and pigment. Many are people who want color without the other effects linked to MT-II.
- MT-II
- Mainly a faster, darker tan. Some also notice, and a few want, its effects on sex drive and appetite.
What people report for tanning
- MT-I
- Usually slower and more gradual, often called even or natural looking. Some fair-skinned people see little change after several weeks.
- MT-II
- Usually faster and darker. Some very fair-skinned people describe a patchy or dirty look at first that later evens out.
Other effects people report
- MT-I
- Appetite and sex drive changes are not a main theme. MT-I is not a stand-in for those MT-II effects.
- MT-II
- Stronger sex drive and erections in some people, and lower appetite that many say fades. Yawning and stretching also come up.
Side effects people mention
- MT-I
- Flushing and nausea still happen, often described as milder. It is not free of side effects.
- MT-II
- Nausea and flushing are the best known complaints. Tiredness, headaches and unwanted erections are also reported.
Freckles and moles
- MT-I
- They can darken. People on forums say it seems less dramatic for many people, but it does happen.
- MT-II
- Darker freckles and moles are reported much more often and more strongly. Some people stopped because of it.
What studies in people show
- MT-I
- Controlled studies of MT-I (afamelanotide) in people found more skin pigment, including in very fair-skinned volunteers. Nausea showed up in the approved implant's trials too.
- MT-II
- Human research is very small. An early study of three men measured more pigment, along with nausea, tiredness and erections.
How the two compare in trials
- MT-I
- No good trial has compared it directly with MT-II.
- MT-II
- No good trial has compared it directly with MT-I. The contrasts on this page come mostly from community reports.
Related approved medicine
- MT-I
- The FDA approved afamelanotide in 2019 as a prescription implant for adults with a light-sensitivity condition called EPP, not for tanning. MT-I sold online is not that product.
- MT-II
- MT-II has no approved use. Bremelanotide (PT-141) is a related but different drug, not MT-II.
Personal accounts, not studies. One account shows what happened to one person.
- MT-I: One person with very fair skin said they had never really tanned before, then slowly built real tan lines on MT-I.
- MT-I: In one thread, people in their 50s described excellent tans on MT-I with less trouble from dark spots than they expected.
- MT-II: One person who normally turns red instead of brown reported clear color on MT-II within days.
- MT-II: On an older bodybuilding forum, very fair-skinned people using MT-II reported strong, even color after struggling to tan before, with darker moles noted in the same thread.
- MT-I: Community reports disagree on whether MT-I needs sun or UV exposure to darken the skin.
- MT-I: One fair-skinned MT-I user was still frustrated after several weeks, seeing red rather than brown color.
- MT-I: One long-term user tried MT-I for a long stretch, then preferred MT-II because it gave them much more color.
- MT-II: One MT-II user stopped early because their face darkened faster than expected and many freckles turned almost black.
- MT-II: One long-time forum user tried MT-II from several suppliers and said it made them very sick each time.
Important cautions
- Both can darken freckles and moles, and MT-I is not an exception. Have a doctor look at any spot that changes quickly, and ask about regular skin checks.
- Sun exposure is still sun exposure. A darker tan or not burning does not make UV harmless, so keep using normal sun protection.
- One fair-skinned MT-II user skipped sunscreen, expecting the compound to help, and burned.
- Nausea and flushing are common with MT-II and still happen with MT-I. Some people using MT-II stopped because the nausea was too much.
- Vials and sprays sold online are not the approved medicine. What is inside, and how much, may not match the label, which also makes personal reports hard to compare.
- Case reports describe melanoma in people who used MT-II, but those reports cannot show it was the cause. The long-term safety of cosmetic use has not been well studied.
- Rare cases of a prolonged erection that needed surgery have been reported after MT-II.
What this comparison does not say
- This comparison does not say either compound replaces sunscreen or other sun protection.
- It does not say either one makes extra time in the sun or on a tanning bed safe.
- It does not say either one is a guaranteed safer choice. Community reports favor MT-I for fewer side effects, but that is not proof of safety.
- It does not suggest using the two together, and it does not treat either one as the same thing as an approved medicine.
Read each one in full
Each page has its own research, cautions and commonly researched dosages.
Studies, labels and community threads behind this comparison. Links open in a new tab.
- FDA prescribing label for the afamelanotide implant (SCENESSE), revised August 2024
- FDA approval letter for Scenesse (afamelanotide), October 8, 2019
- PubMed record: randomized human study of MT-I, skin pigment and UV skin damage
- PubMed record: first human study of MT-II, in three men
- PubMed record: placebo-controlled MT-II study in ten men
- PubMed record: analysis of 623 MT-II forum posts
- Australian TGA safety alert: MT-II tanning products found to be inconsistently dosed
- Skin Cancer Foundation warning about Melanotan II
- r/Melanotan2 thread: one account of switching from MT-II to MT-I because of side effects
- r/Peptides thread: one long-term account comparing MT-I and MT-II
- r/PeptideSelect thread: one fair-skin MT-I experience
- r/Melanotan2 thread: losing patience with MT-I
- r/Melanotan2 thread: early results on MT-II from someone who normally burns