Bad Deal — Susan J. Korman

It's not going to hurt anyone.

Fish hates having to take ADHD medication. It helps him concentrate, but it also makes him feel weird. So when his crush, Ella, needs a boost to study for tests, Fish offers her one of his pills. Soon more kids want pills, and Fish is enjoying the profits. To keep from running out, Fish finds a doctor who sells phony prescriptions. But suddenly, the doctor is arrested. Fish realizes he needs to tell the truth. But will that cost him his friends?