Supplements- did you stop taking them and how did it go?

When it comes to antioxidant supplements like NAC and COQ10, have you stopped taking them, and how did it go afterwards? Is there anyone who stopped taking them and then noticed a decline? Or people who stopped taking them and didn't notice a difference afterwards? I've improved quite a bit with no way of telling how much the supplements helped, but the antioxidant ones are more expensive so I'm thinking about trying out going forward without them.