Hi, Ranchers and Aceace! My dermo started me on 5-FU to the face last Monday, and she said I could use sunscreen from the get-go. She suggested Neutrogena spf 30 For Sensitve Skin. She said this one doesn't have the chemicals. Just be sure to wait at least 2 hours after applying the chemo. The Neutrogena 70 is great also, and she said that is fine to use from the get-go, too, but if it stings, use the 30. Have a great day!