A transdermal/transcutaneous delivery system to deliver Tetrahydrocannabinol (THC) and related compounds, comprising of gel, film and reconstituted liquid for topical application. The delivery system may contain polymethacrylic acid (PMA), carbopol, polyethylene glycol 8000 (PEG), propylene glycol (PG), water, alcohol, acetone, caprylic acid, caproic acid, oleic acid, lauric acid, isopropyl myristate, triethanolamine, and mixtures thereof. This formulation can be used as an analgesic, antiemetic, antiglaucoma medication, arthritis treatment and prevention of weight loss treatment associated with AIDS. It can also be used for treating dementia and multiple sclerosis. The present formulation avoids the problems associated with oral administration, patient compliance and potential abuse associated with other routes of administration of THC.