Nicotine is currently marketed under a variety of names including Habitrol, Nicoderm, Nicorette, Nicotrol, and ProStep. These preparations are used to help wean smokers from cigarettes through topical or systemic intake of nicotine. The products are manufactured as either chewing gum or transdermal patches. Some studies have indicated that a combination of the gum and patch yields enhanced results. Side effects include mouth or throat irritation, redness, itching, and burning.