Many people realized that the pill was just a vitamin

Solution

‘placebo’ means ‘a medicine or procedure prescribed for the psychological benefit to the patient rather than for any physiological effect.’. Heterologous- having a different relation, relative position, or structure; not homologous. Greenlight- to give permission for someone to do something or for something to happen. Nocebo- a bad effect on someone's health caused, for example, by them expecting a treatment not to work or to have side effects. It will contradict the sentence. Many people realized that the pill was just a vitamin tablet and what really changed their disease was the placebo .