Sildenafil
Also called Viagra; Revatio (for pulmonary hypertension)
The first FDA-approved pill for erectile dysfunction (Viagra, 1998). Taken about an hour before sex and works for roughly 4 hours.
Overview
What it is
A small-molecule PDE5 inhibitor, not a peptide, sold as Viagra and as generic tablets.
How it works
It blocks the PDE5 enzyme, which lets cGMP build up in the penis during arousal. That relaxes smooth muscle and increases blood flow. It needs sexual stimulation to work.
What the research shows
Approved by FDA in 1998 after placebo-controlled trials showed improved erections in men with many causes of ED. Label dosing is 50 mg about 1 hour before sex (range 25 to 100 mg), no more than once a day. A heavy, high-fat meal can delay its effect. At lower doses it is also approved (as Revatio) for pulmonary arterial hypertension.
Studied for
- Erectile dysfunctionFDA approved
- Pulmonary arterial hypertensionFDA approved as Revatio
Safety and regulatory status
Safety and side effects
Never combine with nitrates such as nitroglycerin, or with riociguat. Use caution with alpha-blockers. Headache, flushing, indigestion, stuffy nose and a temporary blue tint or light sensitivity in vision are common. Seek emergency care for an erection lasting over 4 hours or sudden loss of vision or hearing.
Regulatory status
FDA approved prescription medicine (Viagra, generics). Requires a prescription.
Common questions
How long does sildenafil last?
Effects usually last about 4 hours. It starts working in 30 to 60 minutes, slower after a heavy meal.
Is generic sildenafil the same as Viagra?
Yes. It contains the same active ingredient and must meet FDA standards.