How does finasteride work?
Finasteride is a type of medicine called a 5-alpha reductase inhibitor.
It works by stopping testosterone (a sex hormone) turning into another hormone called dihydrotestosterone (DHT). DHT can cause your prostate to grow bigger (benign prostate enlargement). It can also stop your hair growing.
Finasteride stops DHT being produced and this helps shrink your prostate and reduce hair loss.
How long does it take to work?
You may notice an improvement a little while after you start taking finasteride.
However, for an enlarged prostate it can take up to 6 months for this medicine to work fully.
For hair loss, you can expect to see some improvement after 3 to 6 months.
Are there any long-term side effects?
Finasteride is generally safe to take for a long time. Many people take it for many months or even years without any problems.
However, there have been reports of breast cancer in some men taking finasteride, but this is rare. Speak to your doctor if you get any changes in your chest area such as lumps, pain or swelling, or discharge from your nipples.
Some men have reported that sexual side effects (such as not being able to get an erection) continued to bother them even after they stopped taking finasteride.
Talk to your doctor if you're bothered by any of these side effects.
Will it affect my contraception?
Finasteride is not thought to stop any type of contraception working. However, this medicine is not usually taken by women.
The manufacturers of finasteride recommend using a condom when having sex because very small amounts of finasteride get into semen, but the actual risk is unlikely to be significant. Most experts agree that this is not necessary.
Can I drive or ride a bike?
Finasteride will not affect your ability to drive, cycle or use machinery.
Can I drink alcohol while taking finasteride?
You can drink alcohol with finasteride.
Is there any food or and drink I need to avoid?
You can eat and drink normally when taking finasteride.
Can lifestyle changes help symptoms of an enlarged prostate?
Making some simple changes to your lifestyle can help with symptoms of an enlarged prostate.
- Drink fewer fizzy drinks and less alcohol, caffeine and artificial sweeteners – they can irritate the bladder and make urinary symptoms worse.
- Quit smoking – nicotine can irritate the bladder and make urinary symptoms worse.
- Drink less in the evening – try to reduce the amount you drink and avoid drinking anything for 2 hours before bedtime. This might help you avoid getting up in the night. Make sure you're still drinking enough fluids earlier in the day.
- Empty your bladder – remember to go to the toilet before long journeys or other situations when you know you may not be able to reach a toilet easily.
- Try double voiding – this is when you finish peeing, wait a few moments, then try to go again. This can help you empty your bladder properly (but take care not to strain or push).
- Check your medicines – ask a doctor whether any medicines you take, such as antidepressants or decongestants, may be making your urinary symptoms worse.
- Eat more fruit and fibre – this can help you avoid constipation. Being constipated can put pressure on the bladder and make your symptoms worse.