CBD patches, also called medical cannabis patches or transdermal patches, are used for localized relief of pain and inflammation.The patches work by opening up the pores of the skin and allowing for a localized absorption of cannabidiol. CBD can come from either cannabis or hemp plants, as long as it contains little to no THC. Once the CBD enters into the system, pain relief is experienced. In addition to localized relief of pain, some studies have shown that CBD patches can relieve pain in some parts of the body.