In the article, "The Placebo Effect", Brian Dunning speaks of some of the factors that make certain placebos more effective than others:
- Blue pills are more effective than red pills for calming or tranquilizing. Red pills are more effective than blue pills for stimulation.
- Two pills have more effect than one.
- Pills with a recognized, well-known brand name and packaging are more effective than generic pills. In one large trial published in the British Medical Journal (Branthwaite A, Cooper P.), branded aspirin was more effective than generic aspirin, which was more effective than a branded placebo, which was more effective than a generic placebo.
- Expensive treatments are more effective than inexpensive ones.
- The description of the placebo's effect is also a powerful factor. Patients who receive a strong warning from the doctor about the strength of the drug have better results than patients who receive a weaker description of the drug's effect. Both groups show better improvement than patients who receive no information about the drug's effect.
- Patients who receive placebos from someone in a white labcoat get better results than when the placebo is administered by someone not wearing a white labcoat.
- Better results are obtained from placebos when the doctor spends more time with the patient explaining things.
- The drama and invasiveness of the placebo is a significant factor in its effectiveness. For example, a shot is more effective than a pill. Electric shock is more effective than ultrasound. Acupuncture is more effective than manipulation.
- Paradoxically, placebo treatments that produce unpleasant side effects are more effective than placebos with no side effects.