What it is used for

Moderate to severe symptoms of an enlarged prostate (benign prostatic hyperplasia)

Read our guides:

Enlarged prostate (BPH)

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Male pattern hair loss, under a specialist

How it works

Dutasteride blocks the enzymes that turn testosterone into dihydrotestosterone (DHT), a hormone that makes the prostate grow. Lower DHT slowly shrinks the prostate over 3 to 6 months.

Side effects

Like all medicines, Dutasteride can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

erection problems
lower sex drive
problems with ejaculation
breast tenderness or swelling

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

breast lumps, pain or nipple discharge
low mood or thoughts of harming yourself

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

Women who are or may become pregnant should not handle leaking capsules, as it can harm a male baby.
It lowers PSA blood test results. Make sure anyone testing your PSA knows you take it.
Do not give blood during treatment and for 6 months after.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.