Popular ED medications found online include: Viagra sildenafil : As the first FDA-approved PDE5 inhibitor for ED, sildenafil is taken 30 minutes to four hours before sexual intercourse to help achieve and maintain an erection. Taking generic ED medications is an effective way to save money without sacrificing quality. By doing so—combined with sexual stimulation—a cascade of events occurs that increases nitric oxide. The generic versions are just as effective and much less expensive. Payment options: Consider how you’d like to pay. Some services offer a subscription option where they’ll send your medications every month at a discount.AdSay Goodbye to Performance Anxiety and Hello to Improved Sexual Stamina! Trust Our Unbiased Reviews and Improve Your Sexual Health in Confidence!Over 20 Years Online · Over Products Tested · Honest & Unbiased Reviews. These lists contain up to 10 of the most common mild side effects that can occur with Viagra, with Levitra, or with both drugs (when taken individually). Can occur with Viagra: mild and temporary.  · Common Levitra side effects may include: flushing (sudden warmth, redness, or tingly feeling); stuffy nose, sinus pain; headache, dizziness; upset stomach; or. back pain. This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at FDA