Sildenafil 25mg / 50mg / 100mg

Sildenafil citrate is the generic form of the best-known ED medication in the world. It is a PDE5 inhibitor: it relaxes blood vessels in the penis so that arousal can produce a firm erection.

The short answer

Sildenafil is an as-needed ED tablet usually taken 30–60 minutes before sex, in 25mg, 50mg or 100mg strengths. A heavy or fatty meal slows how quickly it works. It requires arousal to work, is prescription only, and must never be combined with nitrates.

Active ingredients
Sildenafil citrate
Form
Oral tablet, as needed
Best for
Men who want the classic, well-studied as-needed option
Duration
A shorter window than tadalafil — a few hours for most men

Dosing and timing

Most men start at 50mg and their provider adjusts up or down based on response and side effects. It is taken no more than once in 24 hours. Because sildenafil is absorbed in the gut, a large fatty meal can delay onset noticeably — which is one reason sublingual rapid-dissolve formulations exist.

Side effects

Commonly reported: headache, flushing, indigestion, nasal congestion, and a temporary blue-ish tint or light sensitivity in vision. Seek emergency care for an erection lasting more than four hours (priapism), or for sudden vision or hearing loss.

Who should not take it

Do not take sildenafil with nitrates (nitroglycerin, isosorbide, or 'poppers') or riociguat. Talk to your provider before starting if you have heart disease, low blood pressure, severe liver or kidney disease, retinitis pigmentosa, or if you take alpha blockers for blood pressure or prostate symptoms.

See if it's right for you

A licensed provider reviews your intake and decides whether this treatment is appropriate. Prescription only, subject to approval.

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Compare with tadalafil vs sildenafil or read the Important Safety Information.

Read this part sober

Tadalafil and sildenafil are prescription medications. Treatment is only available after an evaluation by a licensed provider who determines it is appropriate for you. A compounded tadalafil/sildenafil rapid-dissolve tablet is prepared by a licensed compounding pharmacy and is not FDA-approved as a combination product; FDA does not review compounded drugs for safety, effectiveness, or quality.

Do not take this medication if you use nitrates (nitroglycerin, isosorbide) or guanylate cyclase stimulators such as riociguat — the combination can cause a sudden, unsafe drop in blood pressure. Seek emergency care for an erection lasting more than 4 hours. Not for use by anyone under 18, and not for women or children.