Eliminate the appearance of spots in as little as 8 hours with Skin Doctors Overnight Zit Zapper. Skin Doctors Overnight Zit Zapper is formulated with tea tree oil, which has antibacterial properties and has been shown to assist in the treatment of skin infections, including pimples; witch hazel, used as tonic and astringent in the treatment of irritations and local inflammation of the skin; salicylic acid, a type of beta hydroxy acid (BHA) which encourages the sloughing of dead skin cells and has the ability to penetrate into the pore; and zinc sulphate, which acts as an astringent and is useful in the healing of the tissue, preventing scarring, as well as being anti-inflammatory.