Does sunscreen prevent you from tanning?
There is no sun product that stops 100% of UV rays. On a skin protected by a sun product, sunburn is avoided but a very small quantity of UV rays reaches the surface of the skin and activates the increased synthesis of melanin (a pigment present in the epidermis whose role is to protect the nucleus of the cells where the DNA is located from UV rays). This defence reaction of the skin leads to an increase in the skin's tan.
If you do not protect yourself, you risk sunburn: the ""burnt"" cells are eliminated and the tan does not last.