Even if u don't go out much, it's always advisable to apply sunscreen daily irrespective of the weather outside and that too minimum of three times as most of the sunscreens become inactive after 2 hrs.. and the quantity to be applied when it comes to arms is around 5gms each time.. if u r applying less quantity or not repeating then its doesn't protect your skin from tanning. To reduce the tan u have to use a depigm6cream at night.
Health Tips
apply sunscreen three times- 8am 1pm 4pm
apply lots of quantity
apply depigmenting cream at night
use full hand sleeves