Safety
No boxed warning. Never take it with nitrates (such as nitroglycerin or “poppers”) or riociguat: together they can cause a dangerous drop in blood pressure. Don’t combine it with another ED medicine. Get emergency care for an erection lasting more than 4 hours, and stop and call a clinician for sudden vision or hearing loss. Blood pressure can also drop with alpha-blockers, other blood pressure medicines or heavy drinking. Ask a clinician whether your heart is healthy enough for sex.
Legal status
Prescription only; FDA-approved. Viagra is FDA-approved. Compounded sildenafil chewables are not Viagra and not a generic of it, and they aren’t FDA-approved.
What Viagra is
Viagra contains sildenafil citrate, made by Viatris. Approved March 27, 1998, the first PDE5 inhibitor for ED. FDA-approved generic sildenafil tablets are also sold.
FDA-approved for erectile dysfunction.
Dosing
Tablet (25 mg, 50 mg, 100 mg), as needed, at most once a day, 30 minutes to 4 hours before sex. 50 mg for most men, about 1 hour before sex; 25 mg or 100 mg based on effect and tolerance. It can be taken with or without food, though a high-fat meal delays it by about an hour. Your clinician sets the dose for you.
How well it works
In four 12- to 24-week trials of 1,797 men, 63% (25 mg), 74% (50 mg) and 82% (100 mg) reported improved erections, against 24% on placebo. Individual results vary.
Viagra cost
Brand-name Viagra costs $96 a dose at Rex MD and $139 at Hims; generic sildenafil costs $1.60 to $6.25 a dose online (Oct 18, 2026). For a full breakdown, read Where is generic Viagra cheapest online?. For the steps, read How to get Viagra online legally.