Zyclara is an immune response modifier that is used in the treatment of actinic keratosis (a condition that results from excess exposure to the sun) on the face and scalp. Zyclara can also be used in the treatment of genital warts that appear externally on the body. Zyclara can also be used in the treatment of minor forms of skin cancer referred to as superficial basal cell carcinoma, when surgery is not the preferred treatment. Zyclara works by activating the immune system in order to fight abnormal skin growths.