I use factor 30 and reapply frequently and I still tan very well, Ive only ever burned the tops of my thighs at the back and that was a long, long time ago. Its more than likely just your genetic make up. People seem to think that because I am dark haired and dark skinned in the summer, I need less factor but I don't fancy skin damage anymore than the next person. I'm scared of wrinkles way more than I am. Keep up with the high factor and you will eventually go brown if that is how your skin should naturally be.