Viagra
Viagra, or sildenafil, is a PDE5 inhibitor medication used to treat erectile dysfunction (ED). Brand and generic Viagra comes in 25mg, 50mg, and 100mg strengths. Common sildenafil side effects include muscle pain/aches, flushing, headaches, nosebleeds, and difficulty breathing. Learn more about Viagra side effects, interactions, uses, and more in our articles below.