Marys Medicinals- CBD Transdermal Patch- 20 mg CBD Topical Mary’s award-winning transdermal patches are born out of a commitment to accurate dosing through an advanced delivery method. The discreet 2×2″ squares simply adhere to any veinous part of the skin for 8-12 hours of unsurpassed systemic relief. Available in CBD, 1:1 CBD:THC, CBN, THCa, Indica and Sativa.