Common side effects include headache, facial flushing, indigestion, and dizziness. In some cases, online ED providers accept health insurance. It’s available in 10 mg and 20 mg tablets. However, all medications come with risks. 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. In some cases, ED can cause a strain on relationships and impact self-esteem. The most common side effects of VIAGRA: headache; flushing; upset stomach; abnormal vision, such as changes in color vision such as having a blue color tinge and blurred vision; stuffy or runny nose; back pain; muscle pain; nausea; dizziness; rash.Get drug information. Search for a drug by name or NDC number and get complete drug information. It’s like the printout attached to your refill—only electronic. Help me find my . Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in is also used to treat pulmonary arterial hypertension, a serious heart and lung . Sildenafil (Viagra) is only approved by the FDA to treat erectile dysfunction in males. While some studies did look at the use of sildenafil (Viagra) in females, more .