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. Fact Checker: Daniel Boyer M. While most men tolerate Viagra well, some men may develop moderate side effects such as headaches, flushing, or nasal congestion. You should also call your insurance company to see if they cover erectile dysfunction medications. People can increase their chances of receiving a free sample of Viagra by mail by being proactive and remaining informed. Many men are reluctant or ashamed to talk about erectile dysfunction ED with their doctor or may be unsure whether Viagra is the best option for them. Dosage and Administration The suggested Viagra dosage is 50 mg, given about an hour before sexual activity. · Drugs including Viagra and Cialis lead to an average improvement of 4 to 8 points on the scale used by researchers and clinicians. The team behind the new study suggests that exercise should be more regularly prescribed for people with ED. Not everyone wants to take pills for ED, and some aren’t comfortable with the side effects, .  · Teva’s version of sildenafil debuted at an average cash price of around $30 per pill, roughly 50% cheaper than brand-name Viagra. Since then, more manufacturers have brought generic versions of Viagra to market, bringing prices down even further. Learn more about Revatio.1 This is a generic drug. Even if this drug is covered by Medicare or your insurance, we recommend you compare prices. The MDRx coupon or cash price may be less than.