Finasteride for male pattern hair loss: how it works and when to judge the result

Why hair thins in a male pattern

Male pattern hair loss, or androgenetic alopecia, usually starts with a receding hairline at the temples, thinning at the crown, or both, and tends to run in families. The hair follicles in those areas are sensitive to dihydrotestosterone, a hormone made from testosterone. Under its influence they shrink over the years, each new hair grows thinner and shorter than the last, and eventually a follicle stops producing visible hair.

That gradual, patterned course sets it apart. Hair falling out suddenly or in round patches, or a scalp that is itchy, red, scaly or sore, points to something else and needs a GP or dermatologist to look at the scalp. Thinning that comes with tiredness, weight change or other new symptoms is worth a GP visit too, because an underactive thyroid or low iron can cause it.

Where finasteride acts

Finasteride blocks the enzyme, 5-alpha-reductase type II, that converts testosterone into dihydrotestosterone. With less dihydrotestosterone reaching the scalp, the shrinking of sensitive follicles slows down, and in some men hair that had become thin grows thicker again. It cannot revive follicles that have stopped working altogether, so it works best where hair is thinning rather than where the scalp has long been bald.

The tablet for hair loss contains 1 mg and is taken once a day. A 5 mg tablet of the same substance is a different product, for an enlarged prostate, and is not used for hair. Minoxidil solution or foam works differently, applied directly to the scalp, and is sold in pharmacies without a prescription, so it does not need this assessment.

When you can judge whether it is working

Hair grows slowly, so the mirror is a poor judge from week to week. The product information for finasteride 1 mg says that three to six months of daily use are generally needed before you can expect the hair loss to stabilise, and that continued use is needed to keep the benefit. The fairest comparison is with photographs of the crown and hairline, taken at the start in the same light and angles and repeated every few months.

A realistic first checkpoint is around six months, and the question then is mainly whether the loss has slowed or stopped. If after a fair trial nothing has changed, review the plan with a GP or dermatologist rather than simply carrying on.

The effect lasts only while you take the tablet. According to the product information, the benefit starts to reverse within months of stopping and is generally lost within about a year, so finasteride is a long-term treatment rather than a course.

Who it is for and who it is not for

Finasteride 1 mg is for adult men. It is contraindicated in women: in a woman who is or could become pregnant it could affect the development of a male baby, and women who are or may be pregnant should not handle crushed or broken tablets. A request from a woman of childbearing age will therefore be declined; treatments applied to the scalp are available without a prescription.

Finasteride lowers the result of a PSA blood test, so anyone checking your prostate needs to know you take it, and a history of prostate cancer or a raised PSA has to be considered first. Liver disease matters because the medicine is processed by the liver. A history of depression or suicidal thoughts is important for the reason explained in the next section.

Side effects to weigh before starting

The best known side effects are sexual: lower sex drive, difficulty getting an erection and changes in ejaculation, including a smaller volume of semen. Breast changes such as tenderness, enlargement or a lump should be reported to a doctor.

In 2025 the European Medicines Agency completed an EU-wide review and confirmed suicidal thoughts as a side effect of finasteride tablets. How often it happens cannot be estimated from the available data, and most reports came from men taking the 1 mg tablet for hair loss. The advice is clear: anyone on finasteride 1 mg who notices a change in mood, such as low mood or depression, should stop taking it and seek medical advice. Sexual problems are also a reason to seek advice, as they can contribute to mood changes, and a patient card setting this out is being added to packs of the 1 mg tablet. The agency found that the benefits still outweigh the risks, but this is why the questionnaire asks about your mental health.

How a request is assessed here

The assessment is a written questionnaire, with no video call, no phone appointment and no live chat. It asks whether you are a woman of childbearing age; whether your hair is falling out suddenly or in patches, or your scalp is itchy or red; whether you have or have had prostate cancer or a raised PSA; whether you have or have had depression or thoughts of suicide; whether you have liver disease; and whether you have used finasteride or minoxidil before. The doctor may ask for photographs of your scalp, may suggest that a dermatologist examines it first, or may decline. Prescriptions are issued by lek. Damian Wojno, a doctor registered in Poland, PWZ no. 3211301.

If treatment is appropriate, you receive a cross-border prescription as a PDF by email. Print it and bring it to a pharmacy together with photo identification; there is no PIN code. The pharmacist decides whether to dispense, and the tablets are priced and paid for at the pharmacy, separately from the assessment.