Transdermal delivery system has been extensively employed over the years owing to its advantages over the conventional delivery systems. However, the stratum corneum hinders the penetration of substances through the skin. Microneedle technology is the latest advancement and has gained tremendous attention in transdermal delivery system, overcoming the obstacles of transdermal delivery system and providing advantages over the conventional delivery systems. Numerous studies have been carried out for exploring microneedles. This review article covers the types of microneedles, mechanism of action of microneedles, methodology of drug delivery via microneedles while mainly focusing on the applications of microneedles and their combination with o...