A method for directly delivering whereby a substance is introduced into an intradermal space within mammalian skin which involves administering the substance through at least one small gauge hollow needle having an outlet with an exposed height between 0 and 1 mm. The outlet is inserted into the skin to a depth of between 0.3 mm and 2 mm such that the delivery of the substance occurs at a depth between 0.3 mm and 2 mm.