Amoxicillin is the most widely prescribed antibiotic in the United States — used for strep throat, ear infections, pneumonia, UTIs, dental abscesses, and the H. pylori stomach ulcer protocol. This complete 2026 guide covers the full dosage chart for adults and children, the H. pylori triple and dual therapy protocols, Amoxicillin vs Augmentin vs Azithromycin, the mononucleosis rash warning, penicillin allergy guidance.