Dutasteride vs. Finasteride

Around half of all men and one-third of all women will experience hair loss at some point in their lives.1 So we aren't surprised that more people, including late teens and young adults, are turning to prescription treatments to keep their tresses.2

Besides minoxidil, the most common hair loss treatments today are dutasteride and finasteride. While both belong to the same drug class with similar risks, they've demonstrated different levels of efficacy in clinical studies and generally sell at different price points. The level of risk may also depend on the form of the medicine you’re prescribed (topical or oral). Additionally, the two drugs have different magnitudes of research behind them, which is an important factor to consider when comparing prescription treatments.

In this review, we break down each factor to determine which treatment, and in which form, might offer the best chance of reversing your hair loss and the least danger of imparting lasting side effects. Read on for our full analysis! Or, if you’re in a hurry, here is a quick summary of the most recommendable options.

When we say "best for most people," we're referring to the treatments that generally would be the best starting points among the various application methods of either dutasteride or finasteride. Much of that determination will come down to your underlying health as well as your personal preferences. How well would you tolerate an oral medication or a topical one (from the dual standpoints of routine and physiology)?

Topical finasteride is a highly recommendable option for a couple of reasons. One, it tends to cost less than dutasteride. And two, it balances a high potential for hair growth with a lower risk of systemic side effects than oral medications. Studies have looked into topical finasteride's impact on plasma dihydrotestosterone (DHT, a common driver of hair loss) and found that since it enters the bloodstream at such low levels, it poses fairly little risk of DHT-induced sexual effects such as erectile dysfunction (ED), reduced ejaculatory volume, and reduced libido.15 7 You can also more easily find topical finasteride in a delivery mode that fits your preference. (Not keen on dropper serum? Consider an easy-to-administer spray.)

Meanwhile, oral dutasteride has much to recommend it because studies on relative efficacy have found it to be the most effective hair growth treatment.5 Because it's an oral medication, it's better suited to people who'd rather not deal with a topical product (and don't struggle with swallowing pills). We don't place topical dutasteride as a top recommendation because it has comparably less scientific research behind it than its oral counterpart and is less widely available and often more expensive than topical finasteride.

With all that said, we want to point out that dutasteride and finasteride are only appropriate for one type of hair loss: androgenetic alopecia, also known as male- or female-pattern hair loss. Androgenetic alopecia may be the most common hair loss variety, but there are numerous other types that affect millions. If your hair loss is due to an autoimmune disease process, a separate drug treatment, or anything outside of genetic susceptibility to DHT, then neither dutasteride nor finasteride is likely to help you regrow hair.

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions about staying healthy and living healthier lifestyles.

Our head-to-head comparison between dutasteride and finasteride builds off of thousands of research hours we've cumulatively put into understanding and assessing the hair loss space. Over the years, we've come to be deeply familiar with the myriad prescriptions and supplements used today to treat androgenetic alopecia, not to mention the diverse range of brands dedicated to providing such treatments to those who need them. On top of our existing knowledge base, we looked more closely at how dutasteride and finasteride work toward alleviating hair loss and the points at which one may outshine the other. Along the way, we identified the brands we felt were best equipped to help you acquire the medication you need to support your own hair growth.

Additionally, like all health-related content on this website, this guide was thoroughly vetted by one or more members of our Medical Review Board for accuracy and will continue to be monitored for updates by our editorial team.

Dutasteride and finasteride are both prescription medications for benign prostatic hyperplasia (BPH) and hair loss. They work by inhibiting an enzyme called 5-alpha-reductase, which converts testosterone to DHT. DHT is the principal androgen, or sex hormone, behind androgenetic alopecia — also known as male- or female-pattern hair loss. People with androgenetic alopecia usually have high systemic DHT levels, more androgen receptors about the scalp, and a genetic predisposition to respond excessively to androgens.3 Therefore, inhibiting 5-alpha-reductase prevents your body from producing too much of the hormone that leads to hair loss.

The main difference between dutasteride and finasteride lies in the types of 5-alpha-reductase they inhibit. See, 5-alpha-reductase comes in two forms: type 1 and type 2. Dutasteride inhibits both forms, whereas finasteride acts on type 2 exclusively. A 1999 study published in the British Journal of Dermatology noted that because type 1 is the predominant form in the human scalp,23 dutasteride is theoretically a more powerful inhibitor than finasteride,4 and clinical studies have demonstrated that it is indeed more effective at restoring androgen-associated pattern hair loss.5

To illustrate, a 2014 study found that subjects who received 0.5mg of dutasteride saw, on average, 45% more increase in hair width, around 33% more hair growth on the crown, and 71% more hair growth on the hairline than the 1mg finasteride group. In terms of hair counts, we’re talking around nine hairs per every 1in diameter on the scalp.24

The secondary differences between dutasteride and finasteride are:

• Research: Notwithstanding that finasteride has been around a little longer, it does have a larger body of scientific research behind it compared to dutasteride.
• Cost: Dutasteride generally costs more than finasteride. Using Happy Head's prices as a reference, we see that oral dutasteride ($59) can cost more than two times its finasteride counterpart ($24).
• FDA approval: At this time, dutasteride is FDA-approved only as a treatment for BPH, and its use as a hair loss treatment is off-label. Finasteride, however, is FDA-approved for use on both the prostate and scalp hair.

There are similarities, too — apart from their shared drug class, of course. Chiefly, as oral medications, dutasteride and finasteride can cause sexual side effects in men, namely ED, decreased ejaculatory volume, and decreased libido.6 7 They're linked to decreased libido in women, too, as well as breast swelling, breast tenderness, irregular menstruation, and increased body hair.8 The side effect risk is dose-dependent and generally low in doses used to treat hair loss, but the potential effects are severe enough to give pause to prospective users.

But dutasteride and finasteride are also available as topical solutions, which enter the bloodstream at largely negligible levels and thus pose a greatly diminished side effect risk. Such topicals are also usually combined with minoxidil, which — in an oral medication form — is our go-to first-line recommendation for people with androgenic alopedia and, as a topical, is a popular starting place since topical minoxidil often brings positive effect without requiring a prescription.

Dutasteride and finasteride are prescription medications commonly used for hair loss. Both were originally developed to treat BPH (enlarged prostate), but since hair growth was a side effect, urologists began to prescribe them off-label as hair loss treatments — mostly for men but also for women.

The type of hair loss they treat is called androgenetic alopecia (a.k.a. male- or female-pattern hair loss). They do so by inhibiting 5-alpha-reductase inhibitors (more on that in a later section comparing their effectiveness). As 5-alpha-reductase inhibitors, both drugs are known to cause sexual side effects (covered in greater detail in a later section dedicated to the subject).

Finasteride is the older drug — developed in the 1980s as opposed to dutasteride’s origin in the ‘90s — and has FDA approval as a treatment for both BPH and hair loss, whereas dutasteride is currently approved only for BPH. Today, they're both available in oral and topical forms. As topicals, they’re usually combined with minoxidil.

How they work

As we said, dutasteride and finasteride both belong to a class of drugs known as 5-alpha-reductase inhibitors and were originally developed to treat BPH. So, what's the connection between BPH, 5-alpha-reductase, and hair loss? Let's break it down.

The exact causes of BPH are unknown, but research indicates that dihydrotestosterone (DHT) plays a key role. DHT is an androgen, or sex hormone, that derives from testosterone. It is, in fact, an important androgen for things like fetal sexual differentiation, sexual development in puberty, and muscle growth.9 10 However, as some men age, DHT begins to stimulate cellular growth in the prostate, which consequently enlarges.11

The same DHT is what causes androgenetic alopecia. When a person has too much systemic DHT and excessive amounts reach the scalp, it can shrink the hair follicles and shorten the anagen (or active growth) phase of the hair cycle.9 As a result, not only do you produce less hair but your scalp is no longer conducive to sustaining the hairs you have.

5-alpha-reductase inhibitors act on an enzyme that converts testosterone into DHT (that enzyme is, of course, 5-alpha-reductase). By inhibiting the enzyme, dutasteride and finasteride prevent the conversion from taking place, so you have less circulating DHT to risk affecting your scalp.

How to use them

As oral medications, dutasteride and finasteride should be taken once daily — swallowed whole, with or without food. You should also take them around the same time every day and heed any instructions provided by your prescribing physician.12 13

For topical versions, you should generally apply the formula to a clean scalp. You may need to apply the treatment twice a day, and you can’t shower, go to bed, or wear a hat for several hours after application. Again, adhere to the directions given on the label or by your prescribing physician.

In either form, dutasteride and finasteride are ongoing treatments that should begin to yield results in 3-6 months. Their effects cease as soon as you stop taking them.12 13

Advantage: Dutasteride

Of the two, dutasteride is the more effective hair loss treatment. That’s because dutasteride is a dual inhibitor of 5-alpha-reductase. Understand, 5-alpha-reductase occurs in two forms — type 1 and type 2 — so to be a dual inhibitor means that dutasteride acts on both types, whereas finasteride acts exclusively on type 2.4

Not only does dutasteride have dual-type action, but it also inhibits type 2 more strongly than finasteride does. Those two qualities combined make it more effective than finasteride at inhibiting 5-alpha-reductase. Indeed, a 2022 meta-analysis determined that a daily 0.5mg dose of oral dutasteride has the "highest probability of being the most efficacious treatment" compared to common doses of oral finasteride, as well as to oral and topical minoxidil.5

Not to short-change finasteride, which is still an effective hair loss treatment, and one with even more scientific support behind it than dutasteride. Perhaps notably, it may be especially effective for people who have significant hair growth on body parts aside from the scalp. To illustrate, we can look at a six-month pilot study of oral finasteride conducted in Japan. The study involved 37 patients; 18 of them were considered to be pileous (hairy) in areas apart from the head, and the remaining 19 were non-pileous. By the study's end, almost 90% of pileous patients experienced "excellent or good" efficacy with oral finasteride, whereas only around 32% percent of non-pileous patients experienced the same (nearly 60% efficacy overall).14

Importantly, topical finasteride has a fair bit of its own research to support its efficacy. In 2021, for example, a 24-week study found that subjects who received the topical intervention had "significantly greater" hair counts than those in the placebo group, as well as a "numerically similar" count to those who received oral finasteride.15

Advantage: Finasteride

The side effect profile with any 5-alpha-reductase inhibitor is notable because of its impact on sexual function. DHT is a key player in areas like sexual desire and performance, so reducing its presence in the body can cause ED and reduced ejaculatory volume in men, as well as reduced libido in both men and women.7 6 8

At the 0.5mg dose that's standard for hair loss, a 2018 study on oral dutasteride found that it had a 5% incidence of sexual side effects during the open-label period (when participants continued taking dutasteride after the double-blind portion of the trial), but a 16% incidence during the randomized period.16

With oral finasteride, the standard 1mg dose poses a lower risk. According to a 2012 review, between 2.1% and 4.8% of finasteride users experience "sexual adverse events,"7 which is significantly lower than the 5%-16% range demonstrated with dutasteride.

Still, for many people, even a 2% risk is too much to gamble against. Also, it’s very important to note that sexual side effects may persist even after you discontinue medication. For example, a 2012 study found that men who’d stopped using finasteride reported sexual dysfunction even after six years post-discontinuation,17 and a study from 2018 found similarly persistent (and duration-dependent) effects in rats after discontinuing dutasteride.18

Fortunately, both medications are available as topical treatments with much smaller side effect profiles. To illustrate:

However, because topical versions are usually compounded with minoxidil, you may experience side effects from the latter, which include but aren't limited to:20

• Itching, skin rash, reddening, inflammation, or burning at the application site
• Facial swelling
• Accelerated heart rate
• Flushing
• Headache
• Blurred vision
• Dizziness
• Chest pain
• Weight gain

Advantage: Finasteride

Dutasteride tends to cost more than finasteride. The table below, based on data provided by GoodRx, lays out the current price points for the two medications at nationwide retailers as of December 2024. The regional location was selected at random, the prices are for the lowest quantities and the standard doses used to treat hair loss (0.5mg of dutasteride and 1mg of finasteride), and we’ve excluded any special offers that would skew the values.

In each case, finasteride is at least a few bucks less than dutasteride; and at Walgreens, the cost difference is nearly $15.

You’ll find the same pattern among the leading telehealth providers. Let’s look at Happy Head as an example since it carries both treatments in oral and topical forms:

The price differences between the oral forms are major, with dutasteride being around 60% more expensive across the board. The topicals are more evenly matched, but dutasteride still costs $10 more after the first month.

Besides a brick-and-mortar pharmacy, you can get dutasteride through online pharmacies and telehealth providers such as the options below.

Happy Head

Happy Head has dutasteride in both oral and topical forms. There are a couple of oral options for dutasteride. By itself, oral dutasteride (0.5mg) comes in a one-, two-, or three-month supply for $59, $118, and $177, respectively. But Happy Head also offers a SuperCapsule that contains dutasteride (at the same 0.5mg strength), minoxidil (1.25mg), and vitamin D3 (50mcg); your first month of a SuperCapsule prescription is $49, and it rises to $69/mo for the next couple months before reaching its normal $89/mo price.

The topical solution contains 8% minoxidil on top of dutasteride. The 8% concentration is high and may potentially plateau your hair growth by increasing irritation, which can damage follicles and actually increase shedding. If you experience a high degree of irritation, you'll probably want to discontinue use.

The topical solution is sold on a subscription basis. As with the SuperCapsule, your first month is $49, but then it's $69 for each of the following two months of treatment before the price rises to $89/mo.

Learn more about Happy Head’s dutasteride and other treatments in our full review.

Strut Health

Strut also sells both oral and topical dutasteride. Each option is customizable to some degree. For example, the company’s oral dutasteride can be had at doses between 0.01% and 0.06%, with or without biotin (which, mind, has no proven utility for hair growth in healthy people),27 while the topical dutasteride may contain anywhere from 0% to 7.5% minoxidil. The customizability allows you to tailor the medication to your needs and personal side effect risk.

Whichever form you choose, Strut's dutasteride arrives in 30-day supplies. The oral version costs $39 per month, while the topical is $69.

Read our full review of Strut Health for more information.

Musely

Musely has two separate sets of oral and topical dutasteride treatments — one for men, the other for women. All of them contain minoxidil, though at potentially excessive concentrations in the case of topicals (e.g., 8%). The men's topical has tretinoin, an acne treatment with some hair growth potential;28 and the women's formulations contain spironolactone, another acne treatment as well as an anti-androgen that can be particularly useful for female-pattern hair loss while mitigating the risk of unwanted hair growth on the body.29

On a monthly cost basis, Musely definitely outshines Happy Head and Strut. The men's treatments cost $39 per month for the oral and $30 per month for the topical. For the women's treatments, it's $29 and $30, respectively. Each treatment begins with a three-month supply.

On top of being more affordable, finasteride is available through more online pharmacies and telehealth providers than dutasteride. You may even find a greater variety of administration routes in the topical space (i.e., foams and/or sprays in addition to ointments).

ZipHealth

ZipHealth is a small online pharmacy that offers some of the best prices on common prescriptions. There, a one-time purchase of oral finasteride is $28.99 for 30 tablets, $59.99 for 90, $104.99 for 180, and $204.99 for 360. Subscribing knocks 10% off the base price ($26.09, $53.99, $94.49, and $184.49, respectively).

We’ve written a full review of ZipHealth, so feel welcome to check it out.

Hims

Hims has finasteride in both oral and topical forms. The company isn’t always transparent about its pricing, but we’ve found that a year’s worth of treatment costs $264 for oral finasteride ($22 per month) and $468 for topical ($39 per month).

Hims’ topical treatments are a serum and a spray. The serum includes essential oils and 6% minoxidil, which is close to one of the standard concentrations (5%).21 The spray has 6% or 7% minoxidil, and some users may find it easier to apply than a dropped ointment.

Read our full review to learn more about Hims.

Keeps

Keeps is another one that offers oral and topical versions of finasteride. Keeps’ pricing begins at a lower introductory point and then increases to a higher point for subsequent shipments.

The oral finasteride is available in three-, six- and 12-month supplies. The starting price points are $53.34 for three months, $123 for six, and $234 for 12. After your first supply runs out, the prices go up to $80.01, $135, and $240, respectively.

The topicals ship out every three months. The gel starts at $120 for the first three months and then increases to $180. The foam is $135 to start and then $150 thereafter.

If you’re interested in Keeps, you may want to check out our full review.

Ro

Ro’s oral and topical finasteride treatments are available in quarterly plans. The oral finasteride is $60 per quarter ($20 per month), and the topical is $150 per quarter ($50) per month.

The topical contains 6% minoxidil and 0.025% tretinoin in addition to the finasteride. Tretinoin’s role is to increase minoxidil uptake, a capability it has demonstrated in clinical research.22

Happy Head

Happy Head has multiple varieties of oral and topical finasteride. Too many, in fact, to condense in this small area, so we’ll focus on what we think are the best options.

For the oral finasteride, that would be the SuperCapsule line, which combines finasteride with other ingredients. There are two finasteride-based SuperCapsule variations. One consists of 1mg finasteride, 2.5mg minoxidil, and 2,000IU vitamin D3. The other, called ED Performance, swaps minoxidil for 5mg of tadalafil (generic Cialis) to offset the sexual side effects that oral finasteride may cause. Each costs $36 for the first month and then increases to $89 per month thereafter. Generally, we wouldn’t recommend ED Performance unless you have an ED diagnosis, as these medicines can introduce additional side effects and there’s a risk of developing psychogenic ED (ED owing to psychological factors — in this case, a lack of confidence that one can get or achieve an erection without medicated assistance).25 26

For topicals, we recommend Finasteride + Minoxidil (Aqueous Formula). Its 8% minoxidil is on the high end, but the formula includes hydrocortisone and less alcohol to minimize any irritation that may plateau your hair growth. It costs $48 for the first month and then increases to $119 per month.

Strut Health

Strut’s oral finasteride starts at $25 per month, and you can get 90-day refills for $49. The topical, which contains anywhere from 0% to 7.5% minoxidil, is $59 for a 30-day supply.

Though we recommend topical finasteride or oral dutasteride as the best option for most people, we encourage you to consider your specific hair loss needs to determine which of the available options is ideal. Ultimately what’s best for you will come down to your preferences alongside the advice and recommendations of the prescribing doctor. For instance, if you have reason for concern about particular side effects of oral medication, then a topical option might be your best option. Or if you have particularly sensitive skin, an oral treatment could be preferable.