The placebo effect can occur if you experience a medical benefit from believing that you have had some kind of treatment, for example in the form of a pill, even when you haven’t actually received it
marcos alvarado / Alamy
Drug side effects aren’t usually wanted – unless it is to generate a placebo effect. Researchers have found that a fake painkilling nasal spray worked better when it was spiked with capsaicin, the chemical responsible for the heat of chilli peppers, so that it triggered a very mild burning sensation.