Sildenafil is the generic name for the active ingredient in Viagra. Pfizer developed and brand-marketed it starting in 1998, and generic sildenafil has been widely available in the US since 2017. It is FDA-approved and works by the same mechanism regardless of whether it is sold under the Viagra brand, as generic sildenafil, or as a compounded formulation from a licensed pharmacy. TruVera prescribes sildenafil in both standard generic tablets and custom-compounded forms when that's the better clinical fit.

A standard sildenafil tablet typically begins working in 30–60 minutes and lasts about 4–6 hours. A compounded sublingual troche, which dissolves under the tongue and bypasses first-pass digestion, often works in 15–20 minutes. A heavy or high-fat meal can slow absorption of oral tablets, so many patients take sildenafil on an empty stomach for the fastest and most predictable onset. Sexual stimulation is still required for the medication to produce an erection.

Both are PDE5 inhibitors that treat erectile dysfunction, but they have different durations. Sildenafil is shorter-acting (about 4–6 hours) and is usually taken on demand, 30–60 minutes before sexual activity. Tadalafil (Cialis) is much longer-acting (up to 36 hours) and is available both as an on-demand dose and as a low daily dose for continuous coverage. The right choice depends on how often and how spontaneously you want the medication to work — your clinician will help you decide.

The most common side effects are mild and usually transient: headache, facial flushing, nasal congestion, indigestion, and temporary mild vision changes (a blue-tinged hue or light sensitivity). Rare but serious effects include priapism (an erection lasting more than 4 hours), which is a medical emergency requiring immediate care, and sudden hearing or vision loss. Stop taking sildenafil and seek care immediately if any of these occur.

The most critical interaction is with nitrates — including nitroglycerin, isosorbide mononitrate, isosorbide dinitrate, and recreational "poppers" (amyl or butyl nitrite). Combining sildenafil with any nitrate can cause life-threatening hypotension and is an absolute contraindication. Alpha-blockers (often prescribed for blood pressure or prostate enlargement) require caution and dose separation because they can lower blood pressure when combined with sildenafil. Certain antifungals, HIV protease inhibitors, and some blood pressure medications can also affect how sildenafil is metabolized. Always disclose every medication and supplement you take during your intake.

Yes. You can pause or cancel at any time through your TruVera patient portal — no phone calls, no cancellation fees. If you want to try a different dose, switch between tablets and troches, or explore another ED therapy before canceling, your care team is available to discuss options.