Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 1/20/2021
If you’re beginning to lose your hair and have looked into treatment options, you’ve likely heard of a medication called finasteride.
Finasteride is a prescription medication that’s used to treat hair loss. It’s approved by the FDA and backed up by a large number of scientific studies showing real, measurable improvements in things like hair count and density.
Although finasteride can’t permanently cure male pattern baldness, it’s one of the most reliable, effective treatments available for slowing down, stopping or reversing its effects.
Finasteride works well, but the results it produces aren’t instant. In general, you’ll need to wait a few months before you see any noticeable improvements from finasteride.
Below, we’ve provided more information about how long finasteride takes to work, as well as the typical results timeline you can expect after using finasteride.
We’ve also talked about what you can do to make sure that you get the best possible results from this medication.
Finasteride works by preventing the conversion of testosterone to dihydrotestosterone (DHT), the hormone responsible for male pattern baldness.
Although finasteride starts blocking DHT right away, it usually takes several months for this to produce a noticeable improvement in your hair.
Many men who use finasteride see some improvements after three to four months, with the “final” results from finasteride usually taking about one year.
Finasteride is usually more effective when it’s used with minoxidil, a topical medication that stimulates hair growth.
If you use finasteride, taking photos of your hair every month can make it easier to track your progress and see improvements in your hairline.
Finasteride helps to slow down, stop or reverse hair loss by reducing levels of a hormone called dihydrotestosterone, or DHT.
DHT is an androgen, or male hormone. Early in your life, DHT and other androgens all play key roles in the development of your male features, from your genitals to your voice, bone structure, muscle mass and body hair.
If you’re genetically prone to male pattern baldness, the effects of DHT may also damage your hair follicles and cause baldness. Over time, DHT can bind to receptors in your scalp, shrinking your hair follicles and preventing the growth of new hairs.
Your body creates DHT as a byproduct of testosterone. Finasteride works by inhibiting a group of enzymes called 5-alpha-reductase and stopping your body from converting testosterone into DHT.
By stopping this conversion, finasteride significantly lowers the level of DHT in your body. This slows down or stops the follicular damage caused by DHT and prevents male pattern baldness from worsening.
As we’ve discussed in our guide to the hair growing process, the hairs on your head and body all grow as part of a four-phase cycle that covers everything from growth to regression, resting and shedding.
This process starts with a hair growing from a root in the bottom of the hair follicle. As it grows longer, it eventually gets pushed through the skin and becomes visible. Over the course of one year, your hair grows in length by approximately six inches.
Finasteride enters your bloodstream fairly quickly and starts reducing DHT levels as soon as it’s active in your body.
However, since it takes time for new hairs to grow to a visible length, the results from finasteride aren’t immediate. Most of the time, you’ll notice a gradual, steady improvement in your hair over the course of several months.
As soon as finasteride is metabolized by your body, it will start to reduce the amount of DHT that circulates in your bloodstream.
On average, finasteride lowers the amount of DHT in your bloodstream by around 70 percent — enough to significantly slow down, stop or reverse hair loss from male pattern baldness.
During the first few months of using finasteride, you probably won’t notice much of a change in your hair. Your hairline, crown and general level of hair thickness will probably look exactly the same as normal, with no significant improvements.
This isn’t because finasteride isn’t working. Instead, the lack of visible progress during the first few months is simply because your hair needs time to start growing.
During the first few months, it’s important that you continue using finasteride every day, even if you don’t notice any results. Rest assured that the medication is working — it’s just too early for its effects on your hair to be visible.
After taking finasteride for this amount of time, you may notice that your hair loss has halted, with no further noticeable thinning. You may also notice improvements in your hair in certain parts of your hairline and scalp.
In a study published in the European Journal of Dermatology in 2004, researchers found that men with hair loss showed a “significant improvement” after using finasteride for 12 weeks.
Since your hair needs time to grow, the results after three to six months generally aren’t your “final” results from finasteride.
After taking finasteride for 12 months, you should see a further improvement in your hair that builds on your progress from months three to six.
Most studies of finasteride show significant, noticeable improvements in hair count, thickness and other indicators of hair health after 12 months of treatment.
For example, a 1999 study published in the Journal of the American Academy of Dermatology found that men who used finasteride over a period of one year showed a significant increase in hair count in the frontal scalp (hairline) area.
Clinical trials have also found that about 65 percent of men treated with finasteride show some degree of increased hair growth after 12 months.
Since everyone’s hair is slightly different, there are no precise results that you should expect at the one-year mark. You may have a modest increase in hair growth or significant improvements that are easy to notice.
In some cases, taking finasteride for 12 months may not have a noticeable impact on your hair growth, but will simply prevent your hair loss from worsening.
If you haven’t noticed any improvements in your hair after taking finasteride for 12 months, it’s best to talk to your healthcare provider. If finasteride isn’t effective for you after this amount of time, further treatment may not have a significant effect on your hair loss.
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Finasteride keeps working after the 12 month mark, with most research showing that men who use the medication for the long term continue to see results.
A study from 2003 looked at the results of finasteride over two years. The researchers found that men who used finasteride experienced a 14 percent improvement in hair count after one year of treatment and a 16 percent improvement after two years.
An even longer study from Japan looked at the effects of finasteride on hair loss over five years of treatment. The researchers noted that 99.4 percent of men who used finasteride throughout the study period experienced improvements.
In short, finasteride continues to work for years. After one to two years of treatment, you should see noticeable improvements in your hairline, hair growth and hair thickness.
For the most part, using finasteride is simple — just take one pill every day and pay attention to any changes in your hairline that occur over the next few months.
However, like with other medications, there are several things that you can do to maximize your results from finasteride, keep track of your progress and maintain your new hair after you notice improvements. Try to:
Take finasteride every day. Finasteride is designed for daily use. Take your medication every day, even if you don’t notice any changes in your hairline, hair density or thickness when you first start using it. Skipping finasteride doses or only using the medication every now and then can reduce its effectiveness and affect your results.
Use finasteride and minoxidil together. Although finasteride is effective on its own, it’s more effective when used with minoxidil — an over-the-counter topical medication that stimulates hair growth. If you have noticeable hair loss and want the biggest possible improvement in your hair growth and density, consider using both of these medications together.
Use a hair loss prevention shampoo. DHT-blocking shampoos, such as our Thick Fix Shampoo, help to break down buildup on your scalp that can damage your hair follicles and worsen hair loss.
Take photos to monitor your results. Because you see yourself in the mirror virtually every day, noticing the small, subtle changes in your hair that can occur over the course of several months of finasteride use isn’t always easy. To track your progress, take a photo of your hairline, crown and other areas affected by hair loss every month. Try to use similar or identical lighting conditions so that you have an accurate view of your hairline, hair count and thickness over time.
After you get results, don’t stop using finasteride. Keep taking finasteride, even after you see results. If you stop taking finasteride, your DHT levels will rise and your hair loss may start to worsen again.
Finasteride starts working immediately. However, because your hair follicles need time to begin producing new hairs, it usually takes three to six months before you’ll notice any change in your hairline or hair density.
Most of the time, you can expect to see some results from finasteride after six months of regular daily use, with more definitive results usually visible after one year.
Related read: Finasteride before and after photos