Hyperpigmentation and uneven melanin distribution
MT2 binds to melanocortin-1 receptors (MC1R) on melanocytes. This is going to triggering eumelanin (dark pigment) synthesis. However, melanocytes are not uniformly distributed in the skin. Since it is not even all over the skin, it can lead to patchy tanning.Incorrectly using MT2 use can cause proliferation of melanocytes. This would increasing the number and darkness of moles which obviously is not ideal.
Increased UV sensitivity and photoaging
While MT2 helps massively with getting a tan, it does not offer UV protection. MT2 still is going to need you to be exposed to UV, which can cause photoaging. This means you would have premature wrinkles, sagging skin sun spots etc.
UV exposure can also cause DNA damage which can increase the chances of skin cancer.
MT2 also does not boost melanin's protective capabilities sufficiently, which means that some users report burning more easily despite having that darker complexion.
Other notable side effects
MT2 will bind to the melanocortin receptors MC3R and MC4R which are responsible for appetite, libido, and erectile function, since MT2 is non selective.
As a result of this, apatite suppression from MT2 is a notable side effect that is actually beneficial for looksmaxing. We all know that lean is law, and this will help with that. Since MT2 is going to have an effect on the melanocortin receptors, it can reduce your apatite.
MT2 may also enhance your libido and give spontaneous erections due to the fact it binds to those receptors.