If you are taking sildenafil to treat erectile dysfunction, follow your doctor’s directions and the guidelines in this paragraph. Psychological factors like stress, depression, or anxiety can also contribute. Make sure to get an estimate of when you can expect your prescription in the mail. The dose can be increased to mg or decreased to 25mg depending on its effect. While each PDE5 inhibitor differs slightly, they’re very similar in treating erectile dysfunction. Before starting, stopping, or changing any medications while taking sildenafil, please get the advice of your doctor or pharmacist.Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision. VIAGRA is available by prescription only in 25 mg, 50 mg, and mg tablets. Patients should always ask their doctors for medical advice about adverse events. You are encouraged to report adverse events related to Viatris products by calling (U.S. only). If you prefer, you may contact the U.S. Food and Drug Administration (FDA. Key Specs Cost: Consultation prices vary based on the prescriber; $5 generic prescriptions Medical Consultation Required: Yes Medications Prescribed: .