I know that with propranolol there are different versions and many strengths. Go by the directions that your doc told you. If you take it on a regular schedule each day, then I think it should eventually reach a peak and somewhat steady level, but it also depends on what kind you have (long/short-acting). I have an Rx for Propranolol 20mg (short-acting kind) for occasional heart problems, but I try to not take it. It's not needed every day.