Amoxicillin is a prescription penicillin-class antibiotic that treats certain bacterial infections. It does not treat viral illnesses such as colds or flu. In the United States, it requires a valid prescription from a licensed healthcare provider, and an amoxicillin online evaluation still involves a real clinical review of your symptoms, history, allergies, and current medications. Amoxicillin is one of the most widely prescribed antibiotics in the country. It has been used for decades, but it is not the right choice for every infection or every patient.