Used by millions of men worldwide, finasteride (sold under the brand name Propecia®) is one of the few science-based medications on the market for preventing and, in some cases, reversing hair loss caused by male pattern baldness, or androgenetic alopecia.
Finasteride helps halt hair loss by preventing the body from creating dihydrotestosterone (DHT), an androgen hormone that can damage hair follicles and cause male pattern baldness.
Because of the way finasteride works in your body, it should prevent you from losing hair at your hairline.
Here’s how finasteride works, as well as the impact it can have on hair loss that occurs around the hairline.
Learn how you can use finasteride (either on its own or with other treatments for hair loss) to slow, stop or potentially reverse the effects of male pattern baldness.
Finasteride belongs to a class of medications commonly known as 5-alpha-reductase inhibitors, or DHT blockers.
5-alpha-reductase is an enzyme that converts testosterone—your primary male sex hormone—into a more potent hormone called dihydrotestosterone, or DHT.
As explained in our guide to DHT and male hair loss, if you’re prone to hair loss, DHT can bind to receptors in your hair follicles and cause them to gradually shrink, or miniaturize.
Over time, these hair follicles may stop producing new hairs, causing your hairline to recede and the hair on your scalp to become thinner and provide less coverage.
Some men are more sensitive to the effects of DHT than others, which is why male hair loss can vary in speed and severity.
Most of the time, male pattern baldness begins at the hairline or crown, or sometimes at what’s known as the vertex scalp, which is the area right at the very top of your head.
Your genes typically determine where on your scalp you’ll first notice any hair loss.
For some men, the first sign of hair loss is a receding hairline, while for others it might be diffuse thinning around the crown or other parts of the scalp.
Because the hair follicles at the back and sides of your scalp are more resistant to the effects of DHT, it’s uncommon for these areas to be affected by male pattern baldness.
By blocking the conversion of testosterone to DHT, finasteride prevents hair loss at its source by stopping your body from creating the hormone that causes damage to your hair follicles.
Research shows that finasteride reduces DHT levels by around 70 percent. For most men, this is enough to produce a noticeable reduction in hair loss along with improvements in hair growth.
Although there are numerous studies on finasteride as a treatment for hair loss, only a few look at its effects on hair loss around the hairline.
For example, a 1999 study published in the Journal of the American Academy of Dermatology, which assessed hair growth by counting men’s hair in the frontal scalp, found that daily use of finasteride caused a “significant increase in hair count” over the course of one year.
As well as increasing hair count around the hairline, finasteride also produced an improvement in the appearance of the men’s hair in a photographic assessment.
In short, based on the findings of this study, finasteride appears to produce a real improvement in hair growth around the hairline.
Other research shows that finasteride reduces hair loss in other areas of the scalp commonly affected by male pattern baldness.
For example, research also shows that finasteride reduces hair loss near the vertex scalp, or crown.
In a separate study, also published in the Journal of the American Academy of Dermatology, a team of researchers analyzed the effects of finasteride on men with male pattern baldness over the course of two one-year trials.
The researchers found that finasteride produced a clinically significant increase in hair count by measuring hair growth at the vertex scalp.
So, does finasteride regrow hair? Since hair loss can vary in severity from one man to another, there’s no precise amount of hair that finasteride will help to protect or regrow for everyone.
As a general rule, it’s best to think of finasteride as a form of protection against further hair loss, and not as a guaranteed way to regrow hair you’ve already lost.
However, almost all scientific research shows that finasteride produces a reduction in hair loss and, for many men, improvements in hair growth.
For example, in a study published in the late 1990s, 66 percent of men with hair loss who used finasteride experienced improvements in hair growth over the course of two years, compared to just seven percent of men who used a non-therapeutic placebo.
In the same study, 83 percent of men who used finasteride showed no progression of hair loss over the two-year study period.
Now, does this mean that finasteride will completely restore your hairline? Not necessarily, as a variety of factors all play a role in hair loss.
If you’ve had a receding hairline for some time, or if you’ve already lost a lot of hair around your hairline, finasteride may not completely restore it.
However, using finasteride could cause some amount of hair regrowth in the areas of your scalp where you’ve only recently started to notice thinning and recession.
Finasteride starts working right away, but it may take several months before you notice changes in your hairline or hair thickness.
In one long-term study of finasteride, researchers found that most men saw a mild improvement in their hair after three to six months, with more significant results visible after about one year of treatment.
After one to two years of daily finasteride use, the study participants' ' hair growth stabilized, with finasteride producing a mild to moderate improvement on average.
As you can read in this guide on how long finasteride takes to begin working, there’s no hair loss treatment that produces instant results.
Your hair needs time to grow, meaning it will take several months to see any changes after you start using finasteride, minoxidil or any other hair loss treatment.
It’s important to note that you may not notice visible changes in your hairline after you start using finasteride, even after several months.
This doesn’t mean that finasteride isn’t working for you. If you’re already losing hair, finasteride may help to stop your hair loss from worsening, without producing any visible improvements in your hairline.
If you stop taking finasteride, your DHT levels will return to normal and your hair loss may start again.
Finasteride is a safe, effective and well-tolerated hair loss medication for most men. However, a small percentage of men who use finasteride experience side effects.
Potential side effects of finasteride include a reduced level of sexual desire, problems related to ejaculation, erectile dysfunction (ED), pain or discomfort in the testicles and depression.
While sexual dysfunction side effects such as these can sound alarming, it’s important to keep them in context.
The overwhelming majority of men who use finasteride to treat hair loss don’t experience any severe or harmful side effects.
In a four-year clinical study of finasteride, approximately 5.1 percent of men experienced erectile dysfunction after using finasteride for at least one year.
Interestingly, the same number of men experienced this side effect while taking a non-therapeutic placebo.
Other finasteride side effects, such as decreased libido and ejaculation issues, also occurred at very low rates in long-term clinical trials.
It’s worth noting that this research involved the stronger 5mg version of finasteride, which is sold under the brand name Proscar® as a medication for treating benign prostatic hyperplasia (BPH, or enlarged prostate).
These side effects may be even less common when finasteride is used as a lower 1mg dosage to treat hair loss.
You can read more about these issues and their frequency in detail in our full guide to finasteride side effects.
Finasteride is one of two FDA-approved medications for treating hair loss.
The other is a topical medication called minoxidil, which is sold as a generic product and under the brand name Rogaine®.
Minoxidil is a liquid or foam medication that’s applied directly to the areas of your scalp with hair loss.
It works by accelerating your hair’s growth cycle and increasing the amount of blood that’s able to flow to your hair follicles.
Both finasteride and minoxidil were approved by the FDA as treatments for hair loss that affects the scalp and crown.
Because of this, there isn’t a lot of research that compares their effectiveness as treatments for a receding hairline.
However, one study published in the British Journal of Dermatology found that minoxidil, much like finasteride, is also effective at treating hair loss that affects the hairline.
Other studies have found that finasteride and minoxidil produce the best results in terms of hair growth when they’re used together.
For example, a study published in Dermatologic Therapy found that 94.1 percent of men who used oral finasteride and topical minoxidil together experienced improvements in hair growth over the course of 12 months.
In comparison, only 80.5 percent of the men who used finasteride on its own and 59 percent of the men who used minoxidil experienced improvements.
Based on these findings, if you have a receding hairline and want to treat it, you’ll likely get the best results by using finasteride and minoxidil together.