Can skin regenerate after harmful sun exposure?

Yes it can, actually cancer is the result of the skin (or any other cell) rapidly regenerating in the affected area's. But yeah i suggest using Aloe Vera gel on your skin along with the sunscreens and the spf means the amount of time you can be exposed to the suns more harmful rays. But using Aloe Vera gel can help your skin heal tanning is actually not a natural process they may look nice but there far from health the best thing to do is just get the sun in small doses with sunscreen on you wont be as dark, but you will at least have healthy skin.