Medically reviewed by Katelyn Hagerty, FNP
Written by Our Editorial Team
Last updated 6/1/2021
Perhaps you’ve heard of finasteride from friends, your healthcare provider—or maybe you've read about it online. But what does this funny-sounding drug actually do?
Finasteride is in a class of medications called 5-alpha reductase inhibitors, which work by blocking certain hormones.
It’s a prescribed drug—often in conjunction with other medications to treat benign prostatic hypertrophy (an enlarged prostate gland).
When prescribed for this purpose, finasteride treats urination problems, and usually with a 5mg dose.
Most commonly, though, finasteride is used to treat male pattern hair loss. Here’s how finasteride is used to treat a thinning mop.
It’s important to understand that male pattern hair loss is very common and is nothing to be ashamed of.
In fact, according to the American Hair Loss Association, about 85 percent of men will be affected by male pattern baldness by the time they turn fifty.
Hair loss in men is most commonly caused by dihydrotestosterone (DHT), a hormone that attaches to receptors in your scalp and causes hair loss.
Finasteride works by preventing testosterone from being converted into DHT, which in turn reduces the amount of DHT in the scalp.
A daily dose of 1mg of finasteride has been found to reduce the amount of DHT in the scalp by more than 60 percent.
Because of this, most medical professionals will tell you this prescribed drug really works.
Need more proof? When it was first investigated as a potential solution for hair loss, researchers discovered that about 83 percent of men who took finasteride during clinical trials stopped losing hair.
What’s more, 66 percent of men experienced hair growth after regularly taking the drug for two years.
Finasteride comes in topical and oral forms. Topical finasteride is not FDA-approved, but it has been shown to help with hair growth.
This spray version also contains minoxidil, another topical hair loss treatment.
An oral finasteride tablet is the only prescription DHT-blocking medication that has been approved by the FDA to treat male pattern baldness.
The brand name version of finasteride is called Propecia®, but generic finasteride has the same active ingredient and works just as well.
Here are a few other important tips to know before taking finasteride:
You have to be consistent. To prevent hair loss and encourage regrowth, you’ll want to take finasteride daily. To ensure DHT levels are reduced, take the medication close to the same time every day.
Patience is key. Seeing the results you desire may take some time. That could mean anywhere between three and 12 months before noticing increases in hair growth. And even then, finasteride is only effective as long as you are taking it.
It pairs well with minoxidil. While finasteride works great all by itself, it’s even more powerful when used alongside minoxidil—the over-the-counter topical treatment that boosts blood flow to stimulate hair regrowth.
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One thing to know about taking finasteride for pattern hair loss: There is a very low adverse reaction rate.
Side effects related to sexual dysfunction, though still rare, are the most common.
In clinical trials for finasteride, 1.3 percent of users experienced erectile dysfunction and 1.8 percent reported a decrease in sex drive.
Other potential finasteride side effects include:
Ejaculatory dysfunction, like decreased volume of ejaculate testicular pain
Breast tissue enlargement
Of course, if you have any adverse reaction, you should contact a healthcare provider immediately.
If you’re dealing with male pattern baldness, there is hope for seeing an improvement in hair growth.
Schedule time with a healthcare provider to get medical advice and discuss whether finasteride could be right for you.
Another thing to ask is whether or not a combination of finasteride and minoxidil could benefit your hair loss situation, and help you get your mane back.