Fluorouracil, an anti-metabolite, interferes with replication of skin cells and is often used in the treatment of sun damage and precancerous skin lesions. It has also been demonstrated in studies to be effective in the treatment of warts. A compounded product of 17% salicylic acid and 2% 5- fluorouracil (WartPEEL) is available and quite effective when applied to plantar warts nightly under tape occlusion.5