What Is Propecia and How Does It Work for Hair Loss?

If you’re starting to lose your hair and want to stop it from getting worse, your healthcare provider may suggest using Propecia® — either on its own or with a topical treatment like minoxidil. What is Propecia, though?

Propecia is a research-backed, FDA-approved prescription hair loss treatment you take orally. It contains the active ingredient finasteride and works by stopping testosterone from converting into the hormone dihydrotestosterone (DHT), which causes hair loss or a receding hairline in men.

Numerous studies show that Propecia can slow down, stop, and even reverse the effects of male pattern baldness.

Read on to learn more about Propecia for men, including how it works as a treatment for pattern hair loss. You’ll also find answers to questions about generic Propecia, a rundown of common side effects, and tips on how to access the medication and how to use it.

Propecia is a prescription medication that treats androgenetic alopecia (the clinical term for male pattern baldness). Its active ingredient is finasteride. Currently, Propecia is only available in tablet form.

What is Propecia used for? The U.S. Food and Drug Administration (FDA) approved Propecia for hair loss in 1997. Before that, healthcare providers prescribed the active ingredient finasteride to treat benign prostatic hyperplasia (BPH or enlarged prostate).

A happy side effect? The medication also helped with androgenetic hair loss (aka male pattern hair loss or baldness). So now finasteride is used for this purpose as well.

Propecia Pros and Cons

Before we dive into the details, here are some of the things Propecia has going for it and some potential downsides to consider.

Pros:

• It’s highly effective for addressing hair loss as long as you take it consistently and as directed.

• Results are typically seen within a few months.

• It helps wake up hair follicles, so many men notice more hair on top of their heads, where hair loss is often most noticeable.

Cons:

• It requires consistency to work and only works as long as you take it.

• It may cause moodiness, depression, or sexual side effects, such as decreased semen volume, lower sex drive, and erectile dysfunction.

• It’s not safe for pregnant people.

Finasteride is available in 1-milligram and 5-milligram tablets. But the typical Propecia dosage for male pattern hair loss in men is 1 milligram daily.

If you miss a dose, take it as soon as you remember on the same day as the missed dose. But don’t take a double dose if you forgot to take your tablet yesterday. In that case, just take your next scheduled dose.

Propecia’s active ingredient, finasteride, is part of a class of medications known as 5-alpha reductase inhibitors (or 5ARIs). As mentioned, it prevents your body from converting testosterone into the more potent androgenic hormone DHT.

How does this help with male pattern baldness? To answer that, let’s dig into why this type of hair loss occurs in the first place.

You don’t get pattern hair loss from wearing a hat that’s too tight, washing your hair too often, or using too many styling products — though these things can trigger other types of hair loss issues, like traction alopecia.

Male pattern baldness happens thanks to a combination of genetic factors and the effects of DHT.

Your body produces DHT by converting a small percentage of its freely circulating testosterone—via an enzyme called 5 alpha-reductase.

If you’re genetically predisposed to male pattern baldness (look at male hair loss patterns in your family), the DHT created from this process can bind to receptors in your scalp and gradually cause your hair follicles to shrink—and stop producing new hairs.

Not everyone is equally sensitive to the effects of DHT. This is why some guys go bald in their 20s or 30s, while others maintain a full head of hair well into older adulthood.

How does finasteride fit into this? As a 5-alpha reductase inhibitor, it prevents your body from converting testosterone into DHT.

This lowers the amount of DHT that can bind to receptors in your scalp and, ultimately, protects your hair follicles from DHT-related damage.

Learn more about DHT and its effects on your hair follicles in our full guide to DHT and male pattern baldness.

Propecia—or, more specifically, its active ingredient, finasteride—has been the focus of research for decades. Several studies have found that it can slow down, stop, and even reverse the effects of male pattern baldness.

For example, in a 2012 study, 3,177 Japanese men with androgenetic alopecia were given 1 mg of finasteride daily from 2006 to 2009. Photos of 2,561 men were used to check how well it worked.

The results showed that 87 percent of the men grew more hair after taking the medicine, with hair growth improving the longer they stayed on it.

Less than 1% of the men had mild side effects, and very few stopped taking the medicine because of them. Overall, finasteride was deemed effective and safe for long-term use.

More recent studies have looked at the effects of finasteride on hair growth and male pattern baldness over an even longer period.

In a 2019 study in the journal Clinical Research and Trials, a team of researchers in Japan examined the effects of finasteride in men who’d been using the medication for 10 years.

More than 99 percent of participants showed no worsening of hair loss over the entire decade of using finasteride. Even more impressively, 91.5 percent showed improvements in hair growth.

The researchers concluded finasteride showed “high efficacy and safety” as a treatment for male pattern hair loss.

The finasteride in Propecia starts blocking DHT right away, but it can take several months to produce any noticeable changes in your hair. This is where patience and consistency come in.

Most people start to see results from Propecia hair loss treatment after three to four months of daily use. As the medication starts to work, you may notice:

• Your hair loss slows down, with fewer stray hairs visible on your pillowcase or in the shower drain

• Improvements in your hair thickness and density, especially around the hairline or crown (the area at the top of your head)

Though Propecia is effective for most guys, it won’t completely stop your hair from falling out — and it only works for as long as you use it.

Your hair goes through a natural multi-phase hair growth cycle, and it’s common and normal to shed some hair even if you’re taking Propecia for hair loss.

Make sure to take finasteride every day, even if you don’t notice any change in your hair during the first few months of treatment.

Propecia is an oral medication, so as long as you don’t mind swallowing pills, it’s pretty easy to use.

The tablets are typically taken once a day, with or without food. As with any medication, it’s usually best to take it around the same time each day.

That said, you’ll want to follow your healthcare provider’s instructions for using this medication to make sure you’re taking it as prescribed.

Yes. Propecia was protected by a patent through the 1990s and 2000s, but like many established medications, that patent has since expired. Finasteride, its active ingredient, is now available in generic form.

Generic finasteride is available in the same 1-milligram tablet dosage as brand-name Propecia. It’s equally effective at treating hair loss but is typically less expensive, making it an option worth considering if your budget is a concern.

You can get generic finasteride online, following a consultation with a licensed healthcare professional who’ll determine if a prescription is appropriate.

Learn more in our blog on Propecia versus finasteride.

If you’ve searched online for information about Propecia hair loss medication, you may have seen references to a similar medication called Proscar®.

Proscar is a medication for benign prostatic hyperplasia. It contains the same active ingredient as Propecia but at a higher dosage (each tablet of Proscar has 5 milligrams of finasteride versus 1 milligram for each Propecia tablet).

Your healthcare provider may prescribe Proscar or its generic equivalent if you have an enlarged prostate. Proscar isn’t typically used as a treatment for male pattern baldness.

Millions of men in the United States and around the world use Propecia to treat pattern hair loss, and most don’t experience significant issues.

However, like all medications, Propecia can potentially cause side effects.

The most common side effects of Propecia include sexual issues like:

• Erectile dysfunction (ED)

• Ejaculation disorder (a decreased amount of semen, or ejaculate)

• Changes in sex drive

According to the FDA’s documentation for Propecia, these common side effects were reported by 1.2 to 1.8 percent of men who used the medication in clinical trials.

Although uncommon, other adverse effects have been reported with Proscar (the finasteride medication for enlarged prostate). This includes male breast enlargement (gynecomastia) and breast tenderness or pain, which could create a male breast cancer risk.

Finasteride has also been linked to testicular pain, depression, and infertility for some men.

It’s important to keep in mind that these issues affect only a tiny percentage of people who use Propecia, Proscar, or generic finasteride.

In rare cases, Propecia can cause allergic reactions. If you experience any of the following symptoms, seek medical care as soon as possible:

• Skin rash, itching, or hives

• Swelling on the lips or face

• Difficulty breathing or swallowing

• Breast changes, such as growth, pain, lumps, or nipple discharge

Propecia and other medications containing finasteride might cause finasteride drug interactions when taken with certain other medications.

Be sure to let your healthcare provider know about all medications you currently take or have recently taken before using Propecia for hair regrowth.

Another safety note: Propecia is only approved for use in men. Research has found that finasteride can contribute to birth defects when taken during pregnancy.

To be safe, pregnant people or people who can become pregnant shouldn’t take Propecia or other medications that contain finasteride, and they should avoid touching broken or crushed Propecia tablets.

The medication should also be kept out of the reach of children.

Propecia is only available with a valid prescription. This means you’ll need to talk to a healthcare professional to buy and use it. You can’t get it over the counter.

If you’ve noticed early signs of male pattern baldness and want to use Propecia prescription medication to prevent further hair loss, it’s best to talk to your healthcare provider.

You can buy generic finasteride online through Hims following a virtual consultation with a licensed healthcare professional.

Listen, hair thinning and loss is a normal part of getting older, and sometimes we can’t avoid it.

Still, there are things you can do to help prevent hair loss, keep the hair you have, and support healthy hair growth when using Propecia for the treatment of male pattern hair loss:

• Handle your hair gently. Avoid tight hairstyles, excessive heat styling, or frequent chemical treatments, as these can weaken your hair and lead to damage or loss over time. Opt for loose styles and occasional breaks from heat tools.

• Use a quality brush. Choose a soft-bristled brush to minimize breakage and condition your hair’s cuticles. Brushing gently distributes natural oils, keeping your hair stronger and healthier.

• Nourish your hair from within. Include nutrient-dense foods in your diet, such as leafy greens, nuts, eggs, fish, and sweet potatoes. These provide essential proteins, vitamins, and antioxidants that support hair growth and strength.

• Switch to mild shampoos. Harsh shampoos with sulfates can dry and damage your hair. Instead, opt for shampoos with nourishing ingredients like coconut oil or aloe vera to keep your scalp healthy and hair resilient.

• Wash less often. Overwashing strips your scalp of natural oils, which can weaken hair over time. Consider scrubbing it less often, or at least more gently, depending on your hair type and lifestyle.

Now that you have an idea of what Propecia is and what it’s used for, you might be wondering if it’s right for you.

Here’s what to keep in mind:

• Propecia is an effective medication. It contains finasteride, which is used for male pattern baldness and can slow, stop, or even reverse hair loss.

• It may be even more effective when combined. Consider using finasteride with the topical hair loss medication minoxidil (which comes as a foam or liquid solution) and other science-based hair loss treatments. You can also use a two-in-one product, like our topical finasteride & minoxidil spray.

• Personalized guidance is key. For optimal results in your quest for hair regrowth, it’s best to connect with a healthcare professional to learn more about your individual hair needs and get medical advice on effective hair loss treatment options.

Still need help weighing your options? Check out our guide to Propecia’s cost for pricing and insight into insurance coverage.