OTC medicines are medicines that can be bought without a prescription at a pharmacy or shop. If a drug is available without a prescription, it means that the FDA or another agency that tests drugs and dietary supplements has determined that the drug is safe enough to be used without medical supervision and that the benefits of the product outweigh the risks associated with its use without medical supervision. Drugs for which a prescription is required usually have a higher dose of individual ingredients and using them without a doctor's supervision can be risky to our health.