Protect your skin while preventing sunburn with Ultra-Lite SPF 30 Oil-Free Sunscreen by Peter Thomas Roth. The soothing formula is filled with allantoin, aloe, pro-vitamin B5, and vitamins A, C and E to provide you with a healthy way to shield your skin from the negative effects of UVA and UVB rays. How to use: Apply liberally 15 minutes before sun exposure. Use a water-resistant sunscreen if involved in swimming or intense physical activities where sweating will occur. Reapply at least every two hours.