There are several pills available to treat erectile dysfunction (ED), but the most effective ones are Food and Drug Administration (FDA)-approved ED treatments, such as sildenafil (Viagra®), tadalafil (Cialis), vardenafil (Levitra, Staxyn), and avanafil (Stendra) . These medications work by increasing blood flow to the penis and are classified as phosphodiesterase type 5 (PDE5) inhibitors. Sildenafil (Viagra) is the most commonly prescribed ED medication and is most effective when taken on an empty stomach one hour before sex. However, the best choice of ED medication will depend on various factors, including personal preferences, cost, ease of use, how long the drugs effects last, and side effects. It's important to note that ED medications are prescription drugs and should only be taken under the supervision of a doctor. Over-the-counter ED alternatives are available, but they are not as effective as FDA-approved medications.