Medically reviewed by Jill Johnson, FNP
Written by Our Editorial Team
Last updated 1/6/2023
If you’re starting to develop a receding hairline, bald patch or other common signs of pattern hair loss, you may have considered using the medication finasteride.
Finasteride is one of two medications currently approved by the FDA for androgenetic alopecia, or male pattern baldness. It treats and prevents hair loss by stopping your body from producing dihydrotestosterone (DHT), a hormone that can damage your hair follicles.
Research shows that finasteride is highly effective. In fact, several studies have found that most men with visible hair loss who use finasteride experience either a reduction in hair shedding or a noticeable improvement in hair growth.
However, if you’ve recently started to use finasteride, you may notice that your hair looks thinner than usual. This can be a baffling occurrence. After all, isn’t finasteride designed to prevent your hair from falling out and looking thinner? Can finasteride cause hair loss instead of stopping it?
This issue, which is referred to as finasteride shedding, is a normal side effect of finasteride that occurs as a result of the way this medication protects your hair follicles.
Finasteride shedding and regrowth is a temporary process, and you’ll only need to deal with it at the start of your treatment with finasteride. Still, it can be a stressful experience, especially when it occurs without any warning.
Below, we’ve explained how finasteride works, as well as why finasteride shedding may develop during the first few weeks of treatment with this medication.
We’ve also shared several techniques that you can use to improve your results from finasteride with other hair loss medications, hair care products and more.
As a treatment for hair loss, finasteride works by inhibiting the 5-alpha-reductase enzyme, which is responsible for converting testosterone into DHT.
DHT is an androgen, or male sex hormone. It’s important during your early life for your physical and sexual development. However, as an adult, DHT can attach to receptors in certain types of tissue throughout your body, including hair follicles on your scalp.
Over time, DHT-related damage to your hair follicles can result in thin, damaged hairs that can’t properly penetrate through your scalp.
Our guide to DHT and male pattern hair loss goes into more detail about DHT and its effects on your ability to grow healthy hairs.
So, how does finasteride fit into this? As a treatment for androgenetic alopecia, or male pattern baldness, finasteride works by reducing DHT levels throughout your body, which in turn shields your hair follicles from the effects of DHT.
Over the long term, finasteride works well as a treatment for hair loss. In fact, a 10-year study of finasteride found that more than 99 percent of men who use it experience no further progression of their hair loss over the long term.
However, results from finasteride typically aren’t immediate. It usually takes three to four months before any results are visible, with the “final” results from finasteride visible after about one year of consistent use.
During the first few months of treatment with finasteride, some guys develop more hair loss than normal — a phenomenon that’s known as finasteride shedding, or Propecia shedding.
This might seem odd for a hair loss medication. After all, if finasteride works by preventing your body from producing DHT, how can it make androgenetic hair loss worse?
Currently, although experts aren’t completely sure why finasteride often causes temporary hair shedding, some believe it may be related to your hair growth cycle.
Every hair on your body completes a multi-phase hair cycle that involves distinct periods of hair growth, regression, rest and shedding.
During one phase of this cycle, which is referred to as the anagen phase, your hair grows to its full length before resting and falling out.
The anagen phase for hair on your scalp typically lasts for several years. It’s much shorter for your body hair, which is why the hair on your arms, legs and torso naturally grows to a shorter length than the hair on your scalp and face.
Approximately 90 percent of the hairs on your scalp are in the anagen phase at any given time, with other hairs in different phases of the hair growth cycle.
When DHT binds to receptors in your scalp and damages your hair follicles, it can shorten the anagen phase so much that new hairs eventually stop growing out from your scalp.
After you start using finasteride, your DHT levels drop significantly. In fact, research shows that a typical dose of finasteride lowers the amount of DHT that can freely circulate throughout your body by more than 70 percent.
By blocking DHT, finasteride can promote your hair follicles to enter into the anagen, or growth, phase of the natural cycle of hair growth.
Due to this decline in DHT levels and sudden promotion of hair growth, hair follicles that were in the regression and resting phases of the hair cycle may become active again.
This may cause temporary hair loss as some of your hair follicles shed old hairs to replace them with new ones.
Finasteride shedding can be particularly severe if you also apply minoxidil, a topical medication designed to stimulate hair growth, to your scalp.
Though its mechanism of action still isn’t fully understood, minoxidil is believed to work by encouraging your hair follicles to enter into the anagen phase of their growth cycle. It also improves blood circulation to your scalp, which may provide your hair follicles with more nutrients needed for healthy hair growth.
Like finasteride, minoxidil is known for causing temporary hair loss during the first few weeks or months of use as your inactive strands of hair shed before entering the anagen phase.
If you start to experience hair shedding after you start using finasteride either on its own or with minoxidil, it’s important to stay the course.
Finasteride does work, and the hair shedding you may experience during the first few weeks or months of treatment is a temporary issue.
Keep using finasteride as prescribed and after three to four months, you should begin to notice real improvements in your hair density and general hair growth.
Finasteride shedding is a temporary issue that usually only lasts for a few months. After starting treatment with finasteride, you may notice that certain areas of your scalp have slightly less hair coverage than before, especially under bright lighting or when your hair is wet.
In a clinical trial published in the European Journal of Dermatology, experts found that men with hair loss who used finasteride started to display improvements in hair density after six months of use.
In other words, after six months, any shedding from finasteride has been more than made up for with new hair growth.
Similarly, shedding from minoxidil is generally a temporary issue that completely reverses within the first few months.
If you notice shedding after you start using finasteride, don’t panic. Instead, stay focused on the long term and keep using your medication daily. Over time, you’ll likely notice thin areas starting to fill back in with new, healthier hair as your follicles become active once again.
While finasteride is effective on its own, it’s even more effective when combined with other hair loss treatments and hair care habits.
Below, we’ve shared several tips that you can use to improve your results from finasteride and more easily maintain any hair growth you experience while using this medication.
One of the best ways to improve your results from finasteride is to use minoxidil, a topical hair loss medication, at the same time.
Minoxidil is available as a topical solution and as a foam. It promotes hair growth locally at the scalp level, allowing you to treat hair loss and potentially stimulate hair growth from more than one angle at once.
In one study, researchers compared the effectiveness of finasteride and minoxidil alone with a combination of the two medications.
They found that 59 percent of men who only used minoxidil and 84.1 percent of men who only used finasteride experienced improvements in hair growth after 12 months.
In comparison, a significantly higher 94.1 percent of men who used both hair loss medications together experienced improvements in hair growth.
We offer minoxidil solution and minoxidil foam online, allowing you to easily add this treatment to your hair loss prevention toolkit.
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In addition to using minoxidil with finasteride, washing your hair with a hair loss shampoo like our Thick Fix Thickening Shampoo may help to further prevent hair loss and keep your hair in optimal condition.
Helpful ingredients to look for in a hair loss shampoo include ketoconazole and saw palmetto, both of which have been linked to reduced DHT activity and improved hair growth in scientific research.
However, it’s worth noting that although these ingredients appear to be effective, the scientific evidence for them isn’t as strong as it is for finasteride or minoxidil.
Vitamin B7, or biotin, is a vitamin that plays an important role in the growth process for your hair, skin and nails. Numerous other vitamins also play key parts in promoting consistent hair growth and ensuring your strands of hair remain healthy.
While vitamins don’t appear to have any significant role in preventing male pattern baldness, it’s important to consume a healthy amount of vitamins to keep your hair in optimal condition.
You can do this by consuming plenty of vitamin-rich foods that promote hair growth or by taking a vitamin supplement such as our Biotin Gummy Vitamins.
It can take up to one year for finasteride to produce significant results, meaning you’ll generally need to use this medication for some time before your hair loss stops and new growth occurs.
To keep yourself motivated, it can help to take photos of your hairline and scalp to stay on top of any changes that occur in your hair.
Our guide to taking finasteride before and after photos explains how you can keep track of new hair growth while using finasteride using your camera.
Smoking isn’t just harmful to your heart and lungs — it can also damage your hair follicles and contribute to hair loss.
In fact, a study carried out in Taiwan found that regular cigarette smoking was associated with an elevated risk of developing moderate or severe hair loss in men.
If you’re a smoker, consider quitting. Not only can kicking the habit improve your general health — it may also help you to grow thicker, stronger hair.
Along with minoxidil, finasteride is one of two medications that are approved by the FDA to treat male pattern baldness. It’s highly effective, with most men noticing a reduction in hair loss and a significant increase in hair growth after around one year of consistent use.
It’s common and normal to experience some diffuse hair loss, or finasteride shedding, when you first start to use this medication.
For most men, any temporary hair loss from finasteride reverses within a few months, giving you a thicker, fuller head of hair and fewer worries about male pattern baldness.
We offer finasteride as part of our range of hair loss medications, following a consultation with a licensed healthcare provider who will determine if a prescription is appropriate.
You can also find out more about your options for stopping hair loss and promoting regrowth of hair in our detailed guide to preventing hair loss.