Considering trying finasteride to treat your hair loss? That’s probably a good call—it’s one of only two FDA-approved treatments for male pattern baldness and it works for up to 90% of men.

But if rumors about side effects have you second guessing the medication, you’re not alone. There’s plenty of talk about finasteride online, and it’s difficult to know how much of that information is trustworthy.

Here at Keeps, we consider it our responsibility to give you nothing but credible information backed by real evidence. That’s why all of our articles are reviewed by leading hair loss experts. For this one, we spoke to world-renowned hair disorder expert Dr. Antonella Tosti.

What is post-finasteride syndrome?

Post-finasteride syndrome is a non-medical term used to describe a variety of side effects reported by some people who’ve taken finasteride.

According to the Post-Finasteride Syndrome Foundation, the symptoms can be physical, mental, neurological, or sexual, and can persist even after you stop taking the medication. Severe cases have reportedly included long-term erectile dysfunction, decreased sex drive, and depression, and claims that there’s no known cure for the syndrome.

Wondering why anyone would risk these side effects? The short answer is that although these symptoms are very real, the link between them and finasteride is largely unproven.

So, is there any scientific evidence of post-finasteride syndrome?

According to Dr. Tosti, some doctors aren’t convinced that finasteride is causing the symptoms listed above.

“There is disagreement in the medical community about post-finasteride syndrome.” Dr. Tosti says. “Many hair experts don’t see this condition in their patients, and there aren’t any big studies that prove these symptoms are really caused by the drug.”

What if it is real?

Even if the syndrome is actually caused by finasteride, it’s very rare. According to the Post-Finasteride Syndrome Foundation’s website, “1.2% of young men who took finasteride for 206 days or longer developed persistent erectile dysfunction that lasted an average of 4.2 years after quitting the drug.”

1.2% clearly isn’t a huge number. And given that erectile dysfunction most often affects older men, it makes sense that many guys who are reporting these problems have been taking finasteride for a long time. It’s possible that they might’ve developed erectile dysfunction even if they hadn’t taken finasteride.

That said, these symptoms are debilitating, no matter how rare they are or what’s really causing them.

Are there any side effects for finasteride that are proven?

Like most medications, finasteride can cause side effects. Some of the most common ones are dizziness, weakness, feeling like you might pass out, rash, and swelling in your hands or feet.

The one that most men worry about, which is closely related to post finasteride syndrome concerns, are the sexual side effects. Though rare, in clinical trials, 3.8% of male patients noticed some form of sexual side effects (versus 2.1% of patients using the placebo). While that number is small, we understand the questions it may raise. So, we’ve created a longer explainer on finasteride side effects.

So how should I treat my hair loss?

If you’re already taking finasteride, it’s a good idea to monitor your mood and sexual health. “If you’re on finasteride and are experiencing sexual dysfunction or your mood has changed,” Dr. Tosti says, “you should stop taking the medication and talk to your doctor.”

If you haven’t started taking finasteride and don’t think it’s right for you, minoxidil might be a better choice. It’s an FDA-approved topical treatment that you don’t need a prescription to get.


To sum all of this up: Finasteride is an effective treatment for male pattern baldness that’s proven to stop hair loss. However, it’s not for everyone. And it’s understandable to be concerned about the potential side effects. That’s why we recommend that all men who have questions connect directly to a doctor who can answer them on a more personal, individualized level.

If you’d like to connect with a Keeps doctor today about whether finasteride is right for you, you can get started here.


The information provided in this article is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon the content provided in this article for specific medical advice. If you have any questions or concerns, please talk to your doctor.

Finasteride is an oral medication used to treat male pattern baldness in men only. It is not for use by women. When used by men, finasteride is generally safe but it can also cause serious side effects, including but not limited to allergic reactions, sexual dysfunction, and high-grade prostate cancer. Most patients find that problems with sexual function resolve when they stop taking the medicine. For full prescribing information, view the drug label information.

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