Common side effects include headache, facial flushing, indigestion, and dizziness. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects. 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. Privacy: Confirm that your personal data and payment details are confidential. It’s available in 25 mg, 50 mg, and mg tablets and lasts up to 18 hours. Those with pre-existing conditions should always consult a healthcare provider before taking new medications or supplements. What Are the Symptoms of Erectile Dysfunction?GoodRx Health Promotion disclosureinfoPromotion disclosureinfo Save up to 97% on tadalafil cialis with GoodRxDifferent pharmacies offer different prices for the same medication. GoodRx helps find the best price for you. See all couponsSee all tadalafil cialis prices See all couponsSee all tadalafil cialis prices. Compare prices and print coupons for Cialis (Tadalafil (Cialis)) and other drugs at CVS, Walgreens, and other pharmacies. Prices start at $ $14 View other PDE5 Inhibitors Cialis (tadalafil) is an expensive drug used to treat erection problems in men. It may also be used to treat the enlargement of the prostate gland. This drug is slightly more popular than comparable drugs. It is .