Finasteride for male pattern baldness
Propecia
Peer reviewed by Sid DajaniLast updated by Michael Stewart, MRPharmSLast updated 15 Jun 2022
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Finasteride is for adult men only - it must not be taken by anyone aged under 18 years, or by women.
The dose is one (1 mg) tablet a day.
Side-effects are uncommon, but may include a loss of sex drive and a reduced ability to get an erection.
In this article:
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About finasteride for male pattern baldness
Type of medicine | 5-alpha reductase inhibitor |
Used for | Male pattern hair loss |
Also called | Propecia® |
Available as | Tablets |
Male pattern baldness is the common type of hair loss that develops in many men at some stage. The condition is sometimes called androgenetic alopecia. It is caused by a combination of hereditary (genetic) and hormonal factors.
Hair is made in hair follicles. A hair normally grows from each hair follicle for about three years. It is then shed and a new hair grows from the follicle. As balding develops, affected hair follicles gradually become smaller than normal. Each new hair that grows is thinner and shed more quickly than before. This eventually leads to a much smaller hair follicle and a thin hair that does not grow out to the skin surface.
Male hormones are involved in causing these changes. Hair follicles convert testosterone (the main male hormone) into another hormone called dihydrotestosterone. Affected hair follicles become more sensitive to dihydrotestosterone and this causes the hair follicles to shrink.
For some men, this normal ageing process can be distressing, particularly if it is excessive or occurs early in life. Treatment with finasteride can help prevent further hair loss. It works by stopping the conversion of testosterone to dihydrotestosterone.
Finasteride is only available on a prescription from a doctor, but it is not available on the NHS. This means you will be asked to pay the full price of the tablets when you receive your supply.
Before taking finasteride
Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking finasteride it is important that your doctor knows:
If you have ever had an allergic reaction to a medicine.
If you are taking any other medicines. This includes any medicines which are available to buy without a prescription, as well as herbal and complementary medicines.
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How to take finasteride
Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about finasteride and will provide you with a full list of the side-effects which you may experience from taking it.
Take one (1 mg) tablet each day, exactly as your doctor tells you to. Try to take your doses at the same time of day, as this will help you to remember to take finasteride regularly.
Swallow the tablet whole (without breaking or crushing it) with a drink of water. You can take the tablet either with or without food.
If you forget to take a dose on time, take it when you remember. If you do not remember until the following day, leave out the missed dose. Do not take two doses together to make up for a forgotten dose.
Getting the most from your treatment
Each time you collect a new supply of tablets from your pharmacy, make sure they look to be the same as you have had before. This is because there is a high-dose brand of finasteride tablet available for the treatment of a different condition. If you are unsure that you have the correct tablets, ask your pharmacist to check for you.
Your hair growth may start to improve within a few months, although it can take up to a year or so for you to notice the full benefit. You will need to continue treatment to maintain this effect, as the balding process returns when you stop.
Finasteride may cause harm to an unborn baby. Because of this, women who are pregnant should not handle the tablets. Also, very small amounts of finasteride will be in your semen while you are taking this medicine. If you need further advice about this, speak with your pharmacist or doctor.
If you are having an operation or any medical treatment, tell the person carrying out the treatment that you are taking finasteride. This is because finasteride can interfere with a blood test used to detect prostate cancer, so you must tell your doctor about taking finasteride if you need this test.
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Can finasteride cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones associated with finasteride. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.
Finasteride side-effects (these affect fewer than 1 in 10 men) | What can I do if I experience this? |
Reduced desire to have sex, inability to get an erection, breast tenderness, depressed mood, allergic-type reactions | If any of these become troublesome, speak with your doctor |
Important: if you develop any pain or lumps in your breast area, or any discharge from your nipples, you should tell your doctor. This is because there have been a few rare reports of breast cancer in men taking finasteride.
In addition, there have been reports of depression in men taking finasteride, and in rare cases, thoughts of self-harming. If you develop any signs of depression whilst being treated with finasteride, stop taking it and make an appointment to see your doctor.
If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice.
How to store finasteride
Keep all medicines out of the reach and sight of children.
Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
Important information about all medicines
If you buy any medicines check with a pharmacist that they are safe to take with your other medicines.
Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Report side effects to a medicine or vaccine
If you experience side effects, you can report them online through the Yellow Card website.
Further reading and references
- Manufacturer's PIL, Propecia® 1 mg tablets; Merck Sharp & Dohme Limited. The electronic Medicines Compendium. Dated February 2021.
- Medicines Complete BNF 85th Edition; British Medical Association and Royal Pharmaceutical Society of Great Britain, London.
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Next review due: 14 Jun 2025
15 Jun 2022 | Latest version
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