Tadalafil is a medicine used to treat erection problems (erectile dysfunction) and symptoms of an enlarged prostate (benign prostate enlargement).

It’s also sometimes used to treat pulmonary hypertension (high blood pressure in the blood vessels that supply the lungs).

If you have erection problems, tadalafil works by temporarily increasing blood flow to the penis when you get sexually excited.

If you have symptoms of an enlarged prostate gland, such as difficulty peeing or needing to pee urgently, tadalafil works by relaxing the muscles in the prostate and bladder.

In pulmonary hypertension it works by relaxing blood vessels in the chest.

Tadalafil is not usually used to treat benign prostate enlargement because there is not enough evidence about how well it works.

Key facts

It usually takes 30 to 60 minutes for tadalafil to work for erectile dysfunction. You can take it at least 30 minutes before you want to have sex.

Taking tadalafil alone is not enough to cause an erection. You need to be sexually aroused for it to work.
The most common side effects are headaches, feeling sick, indigestion and facial flushes.

It can be dangerous to take tadalafil if you also take medicines called nitrates (often prescribed for chest pain). This combination can cause dangerously low blood pressure. If you’re not sure if you’re taking a nitrate, ask your doctor or pharmacist.

Do not drink grapefruit juice if you’re taking tadalafil for pulmonary hypertension. It affects the way the medicine works.