To address the widespread problem of half of all patients failing to take prescribed medications as directed by their physicians, the present inventor devised, among other things, one or more medication reminders. For example, one embodiment, particularly suitable for only two- or three-a-day prescriptions, comprises a repositionable indicator mechanism that attaches via a self-adhesive microsuction backing to the top or other surface of a plastic prescription medication bottle. The indicator, which can take the form of a slider that moves between two or three indicator positions, in some cases using a detent locking mechanism, to simultaneously indicate the prescribed dosage frequency, last dosage taken, and remaining dosages for a day.