Does a person with add and taking medication can eventually get cured and stop taking stimulants and be ok?

Variable Picture. The medications used for adhd are not intended to "cure" symptoms - they are intended to help improve functioning so that the symptoms are not as much of a problem. Over time, some people are able to develop non-medication strategies that help make medications less needed. With kids, sometimes increased maturity helps to make treatment less necessary.
Impossible to Predic. Some people may eventually become independent of the need for medication, but many will not. The important thing is to maintain a good working relationship with your supervising doctor, who can help you avoid getting into an abuse cycle with the medication. If you need it for the long term, it can be successfully used without any adverse consequences, with optimal management.