Transdermal patches on the other hand are something else entirely. Transdermal patches deliver a high dose of their constituents through the skin that will eventually seep into the bloodstream. Therefore, for cannabis-infused transdermal patches, the high dose of THC delivered into the bloodstream is bound to show up in a drug test. Therefore, for users of transdermal patches, they should be sure to know that in drug tests, the patches will lead to a positive result.