Finasteride
NHS information about the medicine finasteride, including what it's used for, who can take it, how to take it and side effects.
What finasteride is for
Finasteride is used to treat an enlarged prostate.
It's also used to treat hair loss in men, but this is not available on the NHS. Finasteride for hair loss is only available with a private prescription, so you'll need to pay for the full cost of the medicine.
Finasteride works by lowering the amount of a hormone in your body called dihydrotestosterone. This helps to reduce swelling in your prostate, if you're taking it for an enlarged prostate. It can also help reduce hair loss in men.
How to take finasteride
Finasteride usually comes as tablets you swallow.
How much you need to take and for how long depends on your symptoms. Most people need to take finasteride once a day. You'll usually need to take it for 3 to 6 months before your symptoms improve.
When taking finasteride tablets:
- swallow them whole with a drink of water
- try to take them at the same time every day
- take them with or without food
Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or have any problems taking it.
While taking finasteride you'll usually need to have regular check-ups to find out how well it's working.
If you need a PSA test while taking finasteride, tell your doctor because it can affect the result of the test.
Side effects of finasteride
Like all medicines, finasteride can cause side effects, although not everyone gets them.
Side effects of finasteride include:
- erection problems (erectile dysfunction)
- low sex drive (loss of libido)
- problems ejaculating
- infertility after long-term use
Finasteride will not usually affect your ability to drive, ride a bike or use machinery.
More about side effects
These are not all the side effects of finasteride.
For a full list, see the leaflet that comes with your medicine or search for your medicine leaflet on the electronic medicines compendium website.
You can report any side effects you get on the Yellow Card website
Who can and cannot take finasteride
Most adult men can take finasteride.
But finasteride is not suitable for everyone. For example, it may not be suitable if:
- you've had an allergic reaction or other serious side effect from finasteride
- you have a blockage in your urinary tract (kidneys, bladder or urethra)
- you have liver problems
Before taking finasteride, tell your doctor if you have any medical conditions.
Finasteride is not prescribed for women. If you're pregnant you should not touch broken or crushed finasteride tablets. Get advice from a GP or pharmacist if you're pregnant and have touched or swallowed finasteride.
Taking finasteride with other medicines, food and drink
There are some medicines, remedies and supplements that may not mix well with finasteride.
This includes:
- other medicines containing finasteride
- dutasteride
Before taking finasteride, tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements.
Food, drink and alcohol with finasteride
You can eat and drink as normal while taking finasteride.
Find out more about your medicine
To find out more about your medicine, you can:
- check the leaflet that comes with it
- search for your medicine leaflet on the electronic medicines compendium website
- speak to a pharmacist or a doctor for advice
