What's "on medication" mean?
Native speaker’s answer
Rebecca
"On medication" means to have medicine prescribed by a doctor and to take it regularly. Here it implies that he has an actual mental illness and is taking medicine for it. This specific use to refer to mental illness could be considered rude these days if used as a joke or to be mean since people are raising awareness around mental illness and how it affects people. But "on medication" can be used for many things! Ex: I'm on medication for my diabetes problem. Ex: I went off medication last week. Ex: She's on medication and the side effects are terrible.