Oral finasteride is one of the only medications currently FDA-approved for treating male pattern hair loss. This drug works by altering the body’s levels of a certain form of testosterone called DHT.
Over time, exposure to DHT causes hair follicles to shrink, so that the hairs they produce are extremely thin and are less visible. It also causes hair follicles to spend less time in the growth phase and more time in the resting phase, so that there are fewer hairs growing at any given point in time. By reducing the levels of DHT, finasteride prevents these effects, allowing the hair follicles to stay in the growth phase for longer and to grow more robust and visible hairs.
Oral finasteride is highly effective for male pattern hair loss. The majority of men who take oral finasteride experience a significant regrowth of hair, particularly on the crown of the head. This medication can also be used for female pattern hair loss, although it may not be quite as effective in women as it is in men. It’s also important to recognize that taking finasteride during pregnancy poses serious risks to the baby, so women who are or may become pregnant should avoid this medication.
At the same time, altering hormone levels does have the potential to lead to side effects. Some men report experiencing significant side effects from finasteride, mostly related to sexual function as well as mood. The risk of these side effects is low, but they can occur. In the vast majority of cases, any side effects will disappear after a person stops taking finasteride. There have been a few cases of men continuing to report side effects over the long term, although researchers are not yet certain that these effects are related to finasteride.
Finasteride is a 5-alpha reductase inhibitor. It reduces the activity of an enzyme called 5-alpha reductase, which converts testosterone into a more powerful form known as dihydrotestosterone, or DHT. This enzyme is found in many tissues throughout the body, including in the scalp.
When hair follicles are exposed to DHT over a long period of time, they undergo a process of miniaturization, meaning that the follicle shrinks. The hairs that grow from these follicles are much thinner than regular hairs are. This makes them hard to see, so that the area appears to be bald.
DHT also affects the phases of hair growth. Each hair follicle naturally goes through a growing phase, which can last for up to a few years in a healthy follicle, and a resting phase. DHT shortens the growing phase, which translates to fewer hairs on the scalp at any given time.
The sensitivity of your hair follicles to DHT is largely determined by genetics. In some people, the hair follicles are highly sensitive to DHT, and will be affected earlier in life. Others have hair follicles that are more resistant, and will not undergo DHT-related changes until much later in life.
Although oral finasteride is highly effective for male pattern hair loss, it doesn’t necessarily work right away. This is because the effects of DHT on the hair follicles are chronic, and it takes many years for exposure to DHT to cause the hair follicle to shrink. Once the DHT is removed, it takes some time for the hair follicle to recover from that DHT exposure and begin growing healthy hair again.
In general, it takes a few months for the benefits of oral finasteride to start to become apparent. The effects will continue to improve over time. One study of nearly 2000 men on oral finasteride found that after one year, 48% of the men taking finasteride had significant improvement of their hair loss. After two years, this had increased to 66%. This means that, in more than a third of the men who had not seen a treatment effect after a year, the treatment became effective after two years.
If you decide to try finasteride, it’s important to realize that it can take quite a while for it to show the results that you’re hoping for. Most men do see a benefit from finasteride, but this may not be apparent for several months to more than a year after you start taking it.
Finasteride was the first medication to be FDA-approved for treating male pattern hair loss, and it’s been found to be effective in a number of studies. In one study of men with hair loss on the crown of the head, 83% of them experienced no further hair loss after two years, and 61% had significant hair regrowth.
In a study of men with receding hairlines, finasteride was still effective, although not quite as significantly. After one year, 70% of the men hadn’t had any further hair loss, and 37% had experienced significant hair regrowth. Finasteride is considered to be most effective for hair loss on the crown of the head, but it can still work for hair loss at the front of the head.
Without any treatment, most men will continue to experience hair loss over the next few years. Finasteride slows down this process, but can’t always stop it completely. In a five-year study of men taking daily finasteride, 65% of them actually had an increase in hair thickness, compared with their baseline before they started treatment. Only 10% of men experienced some loss of hair over that time period. By contrast, 75% of the men in the control group had significantly reduced hair thickness after five years.
Although finasteride may not always completely stop the loss of hair over time, it does slow down the process, and stops or even reverses it in many men. Finasteride treatment must be continued in order for the medication to remain effective. If you stop taking finasteride, then you’ll start experiencing hair loss again.
While many people think of age-related hair loss as a problem only for men, women can also lose their hair as they age. In general, the pattern of hair loss tends to be different for women than for men. The hairline is usually preserved in women, and they generally experience thinning of hair across the top of the head (rather than a clear bald spot that gradually expands, as is common in men).
Studies on the effectiveness of oral finasteride in women have had mixed results. Some have shown that it’s effective; for example, one study showed that, after three years of taking oral finasteride, 82% of women had a significant increase in hair thickness. However, there have also been some studies that have shown that finasteride didn’t work any better than a placebo (an inert pill containing no medication, which is used for comparison).
In general, minoxidil is considered to be the first line of treatment for women with age-related hair loss. This is another prescription medication, which is available in both oral and topical forms. However, if minoxidil isn’t effective or causes unwanted side effects in a woman, finasteride is a possible alternative treatment that could be considered.
It’s important to recognize that finasteride can’t be used during pregnancy, because it poses serious risks to the baby. Many women experiencing hair loss have already gone through menopause, and won’t need to worry about this. However, for those who are or may become pregnant, finasteride is not a good option. Premenopausal women may be able to consider taking finasteride if they’re also using effective birth control.
For many men, when they consider taking a medication that affects testosterone levels, they may be particularly worried about sexual side effects. Because of this, some men are concerned that finasteride could affect their sexual function.
It’s true that this can happen. In fact, impacts on sexual function are the primary side effects that have been found for oral finasteride. These include decreased sex drive, erectile dysfunction (trouble getting or maintaining an erection), and ejaculation disorders (such as premature ejaculation, delayed ejaculation, or inability to reach orgasm). These issues occur about twice as often in men taking finasteride as they do in a control group of men who are taking a placebo (a pill without the medication, which is used for comparison).
Although this may sound concerning, it’s important to note that most men taking finasteride don’t have any impact on their sexual function. Sexual side effects occur in less than 2% of men taking oral finasteride, and only 1.2% of men stop taking finasteride because of them. Similarly to men, women who take finasteride can also experience a decrease in sex drive.
Fortunately, the sexual side effects of finasteride have generally been shown to be reversible. Most of the time, if a man experiences sexual side effects from finasteride, these will go away after he stops taking the medication.
Besides the sexual side effects, there are a few other risks to be aware of with finasteride. One is that this medication can have an impact on mood. Research has shown that there’s a small but significant increase in the risk of depression in people taking finasteride. Suicidal thinking, and even attempts to commit suicide, are also more common with finasteride. If you start taking finasteride, it’s very important to be watchful for these types of effects, and to seek help for any suicidal thoughts as quickly as possible.
There’s also a relationship between finasteride and the risk of prostate cancer. Studies have found that finasteride actually decreases a man’s overall risk of prostate cancer. However, if a man does get prostate cancer, it’s significantly more likely to be an aggressive cancer if he’s taking finasteride.
In the vast majority of cases, the effects of finasteride are reversible. However, there have been a few men who have reported that they’re continuing to experience side effects over the long term, even months or years after they stopped taking finasteride.
The available scientific evidence has not confirmed that there are any ongoing effects of finasteride, and the medical community doesn’t recognize a “post-finasteride syndrome.” It’s currently unclear what’s happening with the men who experience ongoing side effects, and more research is needed to be certain. Many doctors don’t believe that finasteride is truly responsible for what these men are experiencing.
Some research has indicated that there’s a psychological component to the condition, and stress and anxiety could be playing a significant role in causing these men’s symptoms. It may also be the case that they’re experiencing the effects of aging and other medical conditions, which a person could easily conclude are attributed to finasteride if they’ve taken it in the past. Still, some doctors believe that we need more research into this condition to determine whether finasteride might cause lasting effects in a small subset of men.
The number of men who report ongoing symptoms from finasteride is very small. However, if you’re worried about the potential for this to happen, you could consider other options for treating hair loss instead.
For those who are interested in getting the benefits of finasteride, but are worried about possible side effects from taking it orally, topical finasteride is one option to consider. This involves applying finasteride directly to the scalp in the form of a serum, rather than taking it as a pill. Although some of the finasteride still gets absorbed into the body and can affect DHT levels in the blood, using the medication topically is expected to result in fewer overall side effects than taking it orally. We still need more research comparing the two options to confirm that topical finasteride actually does have a lower risk of side effects.
There are also other options for treating hair loss, which don’t involve changing testosterone levels. These include minoxidil, another prescription medication that’s FDA-approved for treating hair loss, as well as topical caffeine, a more natural alternative. Talking with a dermatologist about your hair loss will give you a chance to discuss your options and ask any questions that you may have, so you’re empowered to make the best decision for yourself about which treatment is best for you.
