Transdermal drug delivery systems (TDDS), also known as ÂÂpatches,ÂÂ are dosage forms designed to deliver a therapeutically effective amount of drug across a patientÂs skin. To cross the drug from transdermal patches to blood there are many barriers for transport. To increase the passage of drugs through skin permeation enhancers are widely used. The role of permeation enhancers arementioned in this review, Apart from permeation enhancers there are some other statergies to increase the permeation of drugs through skin. In this review, we focused about various methods to enhance the permeation of drug from transdermal drug delivery through skin.