Possible Clues:

• Begin to put something harmless into one if one is patient
• Imitation pill
• Ineffective substance given to humour patient
• Medical treatment whose effect is psychological
• Location with nasty smell -- dope found here isn't real
• Sham medicine used in test or for effect
• It works as long as you don't know it shouldn't
• Clinical trial offering, perhaps
• Cope with lab that's processed harmless drug
• Lab cope somehow, producing medicine