How do sildenafil and tadalafil differ for erectile dysfunction (ED)?

Sildenafil and tadalafil work through the same general pathway, but their timing differs. Sildenafil is usually taken before planned sexual activity. Tadalafil may be prescribed before sex or on a daily schedule. These schedules are not interchangeable, so follow your own prescription rather than someone else's directions.

For standard oral tablets, sildenafil is often taken about one hour before sex. Tadalafil taken as needed is generally used at least 30 minutes before sex and may support an erection response for up to 36 hours. Results vary. That window does not mean an erection should last that long. Sexual stimulation is still needed.

A high-fat meal can delay sildenafil's effect. Food generally has less effect on tadalafil. Instructions may differ for a compounded product or another dosage form. Ask your prescriber how to time your specific medicine with meals and sexual activity. A licensed physician in your state will choose an appropriate medicine and schedule based on your health and preferences.