Medically reviewed by Mary Lucas, RN
Written by Our Editorial Team
Last updated 2/13/2021
Although hair loss is a gradual process, it’s often something you’ll notice suddenly, whether it’s in a photograph or when you catch a glimpse of your hairline in the mirror.
While losing your hair can feel like a frustrating experience, several science-based medications are available to slow down, stop or reverse the process. One of these is finasteride.
Finasteride is an FDA-approved medication for treating hair loss. It works by stopping your body from converting testosterone into dihydrotestosterone (DHT), the hormone that’s responsible for male pattern baldness.
Used regularly, finasteride can slow down and stop hair loss from male pattern baldness. Some men who use it even regrow hair in areas with noticeable thinning.
It’s best to start using finasteride, as well as other hair loss medications, as soon as you notice that you’re losing your hair. The earlier you start, the more effective finasteride generally is at stopping your hair loss from getting worse.
Below, we’ve explained when you should start using finasteride and other medications to treat and manage your hair loss.
We’ve also discussed the common signs you may notice if you’ve just started to lose your hair, from thinning to noticeable changes in your hairline.
Finally, we’ve talked more about other medications that can help you to prevent hair loss and retain as much of your hair as possible.
Finasteride works by reducing levels of dihydrotestosterone (DHT), the hormone that’s responsible for damaging your hair follicles and causing male pattern baldness.
The earlier you begin taking finasteride after you notice hair loss, the more effective the medication will be at preserving and protecting your hair.
Finasteride is highly effective, but it’s important to have realistic expectations. If you have advanced hair loss (for example, you have obvious thinning across your entire scalp), it’s unlikely that finasteride will restore all of your hair.
Some men with hair loss experience regrowth after they start using finasteride. However, this isn’t guaranteed.
Finasteride appears to work best when it’s used with minoxidil, a topical medication that treats hair loss and stimulates the growth of new hair.
It usually takes several months to see results from finasteride. After you start taking this medication, it’s important to be patient and consistent.
Finasteride is a prescription medication for hair loss that’s available as a generic medication and under brand names such as Propecia®.
Finasteride works by stopping the conversion of testosterone to dihydrotestosterone (DHT). As we’ve explained in our guide to DHT and male hair loss, DHT is the main hormone responsible for hair loss in men.
If you’re genetically prone to male pattern baldness, DHT can bind to hair follicles in your scalp and gradually prevent them from producing new hairs.
This process can start at your hairline, at the crown of your head or all over your scalp, leading to a variety of different hair loss patterns.
Research suggests that men with significant hair loss often have higher levels of DHT than their peers, as well as hair follicles that are more prone to the effects of DHT and other androgens.
A standard dosage of finasteride can reduce the amount of DHT in your blood by upwards of 70 percent. This reduction in DHT protects your hair follicles from damage and helps to stop male pattern baldness from worsening.
Several scientific studies have shown that finasteride works well as a treatment for male pattern baldness.
For example, a two-year trial published in the Journal of the American Academy of Dermatology looked at the effects of finasteride in more than 1,200 men with male pattern baldness.
Over a period of two years, the men who used finasteride experienced a significant increase in average hair count. In comparison, men who received a non-therapeutic placebo experienced continued hair loss throughout the study period.
A more recent study from Japan looked at the effects of finasteride in more than 500 men with male pattern baldness. This study was even longer, covering a period of 10 years in total.
Over the course of the 10-year study, 99.1 percent of the men who used finasteride noticed no further hair loss. 91.5 percent of the men experienced improved hair growth after starting the treatment with finasteride.
The best time to start using finasteride is as soon as you first notice that you’re starting to lose your hair.
Since finasteride works by reducing DHT levels, starting it as early as possible helps to prevent your hair loss from worsening. The earlier you can reduce DHT, the less time your hair follicles will be exposed to its damaging effects and the less hair you’ll typically lose.
Even if you’ve already lost a significant amount of your hair, it’s generally best to start finasteride as soon as possible.
This is because finasteride often causes hair regrowth, meaning you might grow back “lost” hair in areas of your scalp affected by hair loss. By starting finasteride relatively early, you may have a better chance of seeing improvements in your hair’s thickness and density.
Although hair loss is easy to notice over the long term, it can be difficult to notice a difference in your hair on a day-to-day basis.
One of the best times to start taking finasteride is when you begin to notice the common signs of hair loss, such as significant amounts of hair shedding or a noticeable change in your hairline or scalp.
If you’re worried about male pattern baldness, be on the lookout for these common signs of hair loss:
A noticeable change in your hairline. Hair loss often begins at your hairline. If you’re prone to male pattern baldness, you might notice that your hairline is slowly moving back and turning into a classic “M-shaped” hairline with receding temples.
If you suspect your hairline is receding, try looking at several photos of yourself taken in similar lighting conditions over the course of a few years. If you notice a change in your hairline, it’s a good sign that you’re beginning to lose your hair.
Visible diffuse thinning. Although a receding hairline is a common sign of male pattern baldness, not all men go bald from their hairline.
Another common sign of hair loss is diffuse thinning -- thinning that develops across your entire scalp. Like a receding hairline, you can often spot this by comparing photos taken a few years apart in similar lighting conditions.
Excessive daily hair shedding. Your hair is constantly shedding and growing as part of your natural hair growth cycle. Because of this, it’s perfectly normal to shed up to 100 hairs per day.If you’re shedding more than 100 hairs a day, it could be a sign of hair loss. Take note of how many hairs appear on your pillow, hairbrush or in the shower drain catch -- if it’s more than you’re used to seeing, it could be an early symptom of male pattern baldness.
It’s important not to mistake normal things for signs of hair loss. Contrary to popular belief, a few hairs on your pillow every now and then, an itchy scalp or a genetic widow’s peak usually aren’t reliable signs that you’re losing your hair.
We’ve talked more about what to look for, as well as what not to look for, in our detailed guide to the early signs of balding.
Taking finasteride is easy. Finasteride comes in tablet form, with a standard dosage of 1mg per day for treating and preventing hair loss.
To use finasteride, all you need to do is take a tablet one time per day. Finasteride can be taken with or without food. For optimal results, try to take finasteride at approximately the same time every day.
It may take three to six months of daily use for finasteride to produce a noticeable improvement in your hair. Make sure to keep taking this medication every day, even if you don’t notice any reduction in hair loss or other improvements in the short term.
If you don’t notice any improvements after taking finasteride for six months or longer, it’s best to talk to your healthcare provider.
Finasteride is a safe, effective medication for most men. However, like other medications, it may cause side effects. Data from clinical trials shows that these are generally rare, with only a small percentage of men affected.
Our detailed guide to finasteride side effects talks more about the potential side effects you may experience after treating your hair loss with finasteride.
Finasteride works well on its own. However, it’s even more effective at preventing hair loss and improving hair growth when it’s used with other science-based medications.
One medication that’s particularly effective with finasteride is minoxidil, a topical medication for hair loss that may increase blood circulation and nutrient supply to your hair follicles.
Just like finasteride, minoxidil is backed up by real scientific research showing that it’s effective at treating and preventing hair loss. Research has also found that minoxidil and finasteride are especially effective when used together.
For example, a study published in Dermatologic Therapy in 2015 looked at the effects of topical minoxidil on its own, finasteride on its own and a combination of finasteride and topical minoxidil together as treatments for hair loss in balding men.
The study found that 59 percent of the men treated using minoxidil and 80.5 percent of the men treated using finasteride showed improvements in hair growth, compared to 94.1 percent of the men who used both medications at the same time.
We offer minoxidil online, either on its own or along with finasteride in our Hair Power Pack. You can learn more about how finasteride and minoxidil work together in our full guide to finasteride and minoxidil for treating hair loss.
In addition to minoxidil, other products that could help to prevent hair loss, stimulate growth and maintain your hair include:
Hair loss shampoo. Shampoos that contain ingredients such as ketoconazole and saw palmetto may help to prevent hair loss. We’ve talked about this more in our full guide to what to look for in a men’s hair loss shampoo.
Biotin. An important water-soluble vitamin, biotin (vitamin B7) plays a key role in the hair growth process. While there’s no scientific evidence that biotin stops hair loss from male pattern baldness, taking a biotin supplement may offer other benefits for your hair.
The best time to take finasteride is as soon as you notice that you’re losing your hair. This could be when you first see that you’re shedding more hair than normal. Alternatively, it could be when you first notice that you’re developing a receding hairline or bald patch near your crown.
The earlier you start taking finasteride, the more effective it will typically be at stopping your hair loss from getting worse.
After you start taking finasteride, you’ll need to use it every day in order to maintain your results and keep your hair. Most of the time, you’ll begin to see results after taking finasteride daily for a period of three to six months.
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