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Does Finasteride Regrow Hair? Evidence, Results & Timelines

Medically reviewed by Dr. Meinolf Dorka, Medical Director, last reviewed September 2026

If you are reading about finasteride, you have probably read a great deal already. Forum threads that swear by it, others that warn against it, before-and-after photographs of uncertain origin. It is hard to know what to believe.

Wanting the evidence and the risks laid out plainly before you decide anything is a sensible way to approach a medicine that works only for as long as it is taken.

The short answer

In some men, yes, to a degree. Finasteride is a tablet used for male pattern hair loss. Mayo Clinic reports that many men who take it notice a slowing of hair loss and that some see new hair growth. Slowing further loss is the more commonly described effect.

It does not work for everyone, it may work less well in men over 60, and any benefit is lost after stopping. It also carries side effects, including a risk of mood changes set out in a Swiss safety communication in November 2025.

What finasteride is and how it works

In plain terms, finasteride lowers the level of a hormone that is thought to shrink hair follicles in hereditary hair loss. It blocks an enzyme called 5-alpha-reductase, which converts testosterone into another hormone, DHT. Clinically, finasteride belongs to a group of medicines called 5-alpha-reductase inhibitors.

For hair loss it is taken as a 1 mg tablet once a day. A higher-dose tablet is used for an enlarged prostate. It increases the number of hairs on the scalp, not on the body.

Who it is for

In Switzerland, finasteride 1 mg tablets are authorized for men with mild to moderate hereditary hair loss, according to the safety communication published by Swissmedic. It is not for use by women or children.

Women who are or may become pregnant should not handle crushed or broken tablets, because finasteride can be absorbed through the skin and cause birth defects in male babies. After any contact, wash the skin straight away with soap and water.

Before starting, it is important to tell the prescriber about liver disease, other medicines and supplements, and any plans to have children.

Taking finasteride

Finasteride is taken by mouth once a day with a glass of water, with or without food, at regular intervals. If you miss a dose, follow the instructions in the pack leaflet, but do not take two tablets to make up for it. Finasteride is prescribed for one person and should not be shared, and broken or crushed tablets should be kept away from anyone who is or may become pregnant.

Results: what the evidence shows

The evidence points in a consistent direction: in many men hair loss slows, and in some new hair grows on the scalp.

Several limits apply. Finasteride is used for specific types of hair loss, mainly hereditary hair loss, so the cause needs to be established first. It may work less well in men over 60. And the effect lasts only while the medicine is taken.

Findings from studies describe groups of people, not individuals. Knowing that many men respond does not tell you whether you will.

Timelines: how long before it is possible to judge

Finasteride works gradually. Mayo Clinic says it may take a few months to tell whether it is working for you, and Cleveland Clinic describes at least three months of daily use before any improvement is noticeable. If it is stopped, both organisations note that the hair gained is lost again within about a year.

No responsible clinician will offer a personal timeline in advance. What can be offered is an assessment beforehand, a clear plan, and an agreed point at which to review whether the treatment is helping enough to continue.

Side effects and safety

Like any medicine, finasteride can cause side effects. Recognised side effects include:

• Sexual side effects, such as reduced interest in sex, difficulty getting or keeping an erection, and a smaller amount of semen. Swissmedic advises seeking medical advice if these occur, as they may contribute to changes in mood.
• Breast changes, including tenderness, enlargement, lumps or nipple discharge, which should be reported promptly.
• Allergic reactions, such as rash, itching, hives or swelling of the lips and face.
• Mental health effects, including low mood, depression, anxiety and suicidal thoughts. Difficulties with concentration or memory have also been reported. These effects do not occur in everyone, but they are important to discuss with your prescribing doctor, especially if you have a history of mental health difficulties. The box near the top of this page explains what to do if symptoms appear.
• Effects on prostate testing. Finasteride can affect the results of the PSA blood test used to check for prostate cancer, so any doctor ordering the test needs to know you take it. It may also increase the risk of a high-grade form of prostate cancer.
• Fertility. Mayo Clinic notes that some men taking finasteride have become infertile, so plans to have children are worth discussing first.

Blood should not be donated while taking finasteride, because the blood could reach someone who is pregnant. A patient card is being introduced for finasteride 1 mg to summarise the risks of mood changes and sexual side effects. The UK medicines regulator, the MHRA, also notes that depression, suicidal thoughts and sexual side effects may continue after treatment has stopped.

Apart from stopping because of changes in mood, as Swissmedic advises, finasteride should not be changed or stopped without discussing it with the prescriber first.

What to watch for once you start

Some side effects of finasteride affect mood and sex life, and those can be difficult to raise. It helps to know in advance what to look out for: low mood, depression or thoughts of suicide, reduced sex drive, difficulty getting an erection, or problems with ejaculation.

Sexual side effects can affect mood, and they have also been reported without any change in mood. The MHRA asks prescribers to review people taking finasteride regularly for both. A review is a routine part of treatment, not a sign that something has gone wrong, and it is the right moment to mention any change, however small it seems.

Tablets or a spray on the scalp

A finasteride spray applied to the scalp is also authorized in Switzerland, for men aged 18 to 41 with mild to moderate hereditary hair loss, according to the same communication. The 2025 review found insufficient evidence of a causal link between the spray and suicidal thoughts, so the spray’s product information was not changed. The communication notes that it already describes the mood changes associated with finasteride tablets. Whether a tablet or a spray suits you is a question for the prescriber.

Finasteride and other options

Finasteride is one option among several. Minoxidil, applied to the scalp as a liquid or foam, is used by both men and women and is the other common medicine for hereditary hair loss. A hair transplant is a surgical option for some people, although hereditary hair loss continues to progress afterwards.

Choosing not to treat is also a reasonable decision. Some people prefer to let hair loss run its course, and that choice is yours.

Questions to ask before starting

Before starting finasteride, it is worth asking the prescriber:

• what type of hair loss you have, and how that was established;
• how, and at what point, you will review together whether it is helping;
• which side effects to watch for, and what to do if they appear;
• whether any history of low mood or depression affects the decision;
• how it may affect a PSA test or plans to have children;
• what happens if you decide to stop.

Why authorised supply matters

The WHO warns that substandard and falsified medical products are often sold online and may contain the wrong ingredients or the wrong dose, and it names people buying from unauthorised sources among those at risk. A prescription medicine should be obtained after an assessment and from an authorised source, where its origin and quality are controlled.

Support in Switzerland

A family doctor or a dermatologist can assess hair loss and discuss whether finasteride is appropriate. In family-doctor, HMO and Telmed insurance models, your first contact is expected to go through the doctor or service your model specifies.

Frequently asked questions

Hair loss care at ahtida Health

ahtida Health is a structured digital medical clinic that provides care for hair loss, among other areas. Consultations are available in German and English, and you can find out more about hair loss care at ahtida Health.

If you want to take this further

If you would like to understand whether finasteride or another approach may be appropriate for you, you can explore hair loss treatment options with a clinician.

References

1. Mayo Clinic. Hair loss: Diagnosis and treatment. 7 February 2026.
2. Mayo Clinic. Finasteride (oral route): Side effects and dosage. Portions last updated 1 February 2026.
3. Cleveland Clinic. Hair Loss. Last updated 26 August 2021.
4. Cleveland Clinic. Finasteride Tablets (Alopecia). Date not stated on page.
5. Medicines and Healthcare products Regulatory Agency (MHRA). Finasteride and dutasteride: updated safety warnings for psychiatric side effects and sexual dysfunction (Drug Safety Update). 11 May 2026.
6. Cleveland Clinic. Male Pattern Baldness (Androgenic Alopecia). Last updated 9 December 2022.
7. Cleveland Clinic. Frontal Fibrosing Alopecia. Last updated 13 June 2022.
8. Swissmedic. Finasterid, Dutasterid: Neue Massnahmen zur Minimierung des Risikos für Suizidgedanken. Safety communication from the marketing authorisation holders, in agreement with Swissmedic. 17 November 2025.
9. World Health Organization. Substandard and falsified medical products (fact sheet). 3 December 2024.
10. ch.ch (Swiss federal portal). Emergencies and danger. Date not stated on page.
11. 143.ch. How to contact us (Heart2Heart English line). Last modified 7 December 2023.
12. ch.ch (Swiss federal portal). Health insurance benefits. Date not stated on page.
13. ch.ch (Swiss federal portal). Taking out, changing and cancelling health insurance. Date not stated on page.
14. Brezis M. Finasteride-Induced Neuropsychiatric Reactions. Journal of Dermatology and Skin Science. 27 February 2026.