A small, adhesive device applied to the skin like a bandage that releases a measured dose of a drug into the bloodstream over 24 hours. Skin patches, also called transdermal patches, help overcome the symptoms of withdrawing from nicotine and are used to aid people who want to stop smoking. Skin patches are used daily over a 6- to 12-week period. Side effects may include headache, insomnia, dizziness, anxiety, irritability, fatigue, stomach upset, local skin irritation, diarrhea, or constipation. Skin patches are effective but may not work for all people trying to end nicotine dependency.