Even today the most preferred delivery of drugs is still through oral route but because of some inherited limitations with this route, various other routes have been explored including transdermal. Delivery and complete absorption of the drugs is the major concern these days due to various reasons including poor solubility and incomplete bioavailability, this could be due to incomplete presystemic absorption or presystemic degradation. Transdermal drug delivery system is the method by which the drug absorption occurs through the skin primarily for its systemic effect. It provides better therapeutic efficacy and safety for the administration of insulin. Most of the oral anti-diabetic drug exhibit low bioavailability and hence a poor patient compliance. Hence, it can be used as better site for delivery of numerous drugs including proteins and peptides such as insulin.