Tadalafil is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Tadalafil is in a class of medications informed phosphodiesterase (PDE) inhibitors. It works by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection. Tadalafil does not cure erectile dysfunction or increase sexual desire. Tadalafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus (HIV). Tadalafil comes as a tablet to take by mouth. It may be taken with or without food.

Your physician will probably start you on an average dose of tadalafil and increase or decrease your dose depending on your response to the medication. Tell your physician if tadalafil is not working well or if you are experiencing side effects.

You should tell your physician what herbal products you are taking, especially St. John’s wort and you should tell your physician if you smoke and if you have ever had an erection that lasted more than 4 hours. Also tell your physician if you have or have ever had a condition that affects the shape of the penis, such as angulation, cavernosal fibrosis, or Peyronie’s disease; diabetes; high cholesterol; high or low blood pressure; irregular heartbeat; a heart attack; angina (chest pain); a stroke; ulcers in the stomach or intestine; a bleeding disorder; blood cell worries such as sickle cell anemia (a disease of the red blood cells), multiple myeloma (cancer of the plasma cells), or leukemia (cancer of the white blood cells); and liver, kidney, or heart disease.

A number of patients experienced a sudden loss of some or all of their vision after they took tadalafil or other medications that are similar to tadalafil. The vision loss was permanent in some cases. It is not known if the vision loss was caused by the medication. If you experience a sudden loss of vision while you are taking tadalafil, inform your physician immediately. Do not take any more doses of tadalafil or similar medications such as sildenafil (Viagra) or vardenafil (Levitra) until you talk to your physician.

If Tadalafil 10mg or 20mg pills work for you, but you anticipate taking Tadalafil on a regular basis (to have sexual activity at least twice a week), Tadalafil once-a-day pills may be an appropriate option for you. These pills contain a lower dose of tadalafil (2.5mg or 5mg) and are designed to be taken once a day, every day, allowing you to get an erection and have sex whenever you wish. Tadalafil 2.5mg and 5mg pills should not be taken more than once a day.