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Dutasteride vs Finasteride: Which is better for hair loss?

Medically reviewed by
Dr Meena Zareie (GMC) — Updated on December 29, 2025

When it comes to hair loss, there are two main treatments that most people have heard of before: Finasteride and Dutasteride.

They are two very similar hair loss treatments, in that they both belong to a family of drugs known as 5-alpha reductase inhibitors, or 5-ARIs that prevent your body from producing dihydrotestosterone, or DHT.

However, if you’re just starting your hair loss journey, it can be hard to know which hair loss products work and which is most appropriate for your needs.

In this article, we’ll take you through everything you may need to know about Dutasteride vs. Finasteride so that you can make a final decision on which one you should take to treat hair loss.

Table of Contents

What is Finasteride?
What is Dutasteride?
How do Dutasteride and Finasteride work?
Dutasteride versus Finasteride: Which is more effective?
Why does Dutasteride work better than Finasteride?
Do Dutasteride and Finasteride have the same side effects?
Alternatives to Dutasteride and Finasteride

What is Finasteride?

Finasteride is 5α-reductase inhibitor, also known as a DHT blocker. These drugs help to limit the amount of testosterone in the body that gets converted to dihydrotestosterone (DHT).

DHT is linked to genetic hair loss conditions such as androgenetic alopecia (also known as male or female pattern baldness). It is believed that DHT binds to androgen receptors in the hair follicles causing them to shrink over time and eventually stop producing hair.

It should be noted that all men produce DHT. However, not all men suffer from male pattern hair loss. This is because the amount of DHT produced in the body is determined by genetics which also determines how sensitive hair follicles are to DHT.

Oral Finasteride is available in two strengths:

Finasteride 1mg (this is commonly found under the brand name Propecia). This low-dose Finasteride is used to treat male pattern baldness.
Finasteride 5gm (also known as Proscar). The higher dose of Finasteride is used to treat benign prostatic hyperplasia (an enlarged prostate gland)

Finasteride can also be applied topically to the scalp. Read more about the effectiveness of topical Finasteride.

What is Dutasteride?

Dutasteride is another 5-alpha reductase inhibitor used to lower DHT levels in the body which in turn helps to reduce hair loss.

Just like Finasteride, Dutasteride is available as oral tablet and can also be used to treat benign prostatic hyperplasia (BHP). Dutasteride is only available through a prescription and is often sold under the brand name, Avodart. When taken to treat an enlarged prostate, Dutasteride is often taken with Tamsulosin (aka Flomax Relief) to help treat symptoms.

Unlike Finasteride which is approved to treat male pattern hair loss by the FDA, Dutasteride is not yet approved as a treatment for hair loss and can only be used to treat prostate enlargement.

How do Dutasteride and Finasteride work?

Dutasteride and Finasteride are drugs that block the production of DHT in the body, which is created from testosterone.

DHT is cited as being one of the main causes of hair loss [1], but it also plays a vital role in producing male sex characteristics. That’s why DHT creams are sometimes used to treat hormone deficiencies.

The reason it plays such a major part in genetic hair loss conditions such as male androgenetic alopecia (male pattern baldness) is that this hormone can gradually prevent your hair follicles from being able to grow new hair which, over time, can turn into a receding hairline or bald spots.

Although both these drugs work in a similar way, there are a lot of differences when it comes to their effectiveness and side effects.

Dutasteride versus Finasteride: Which is more effective?

There have been quite a few studies that have explored the effectiveness of Finasteride and Dutasteride. Including a study in the Journal of the American Academy of Dermatology (JAAD) [2] which compared the two drugs on a sample of 917 men between 20 and 50 who were all experiencing hair loss at varying degrees.

Notes on the JAAD study

After a 24-week trial, both finasteride and dutasteride had effectively increased hair growth – but it was the Dutasteride subjects that experienced the most improvement.
Similarly, a review of three studies also found that Dutasteride outperformed Finasteride [3] slightly when it came to hair growth, thickness, and density.
After a 24-week trial, both drugs had effectively increased hair growth – but it was the Dutasteride subjects that experienced the most improvement.
Similarly, a review of three studies also found that Dutasteride outperformed Finasteride [3] slightly when it came to hair growth, thickness, and density.

The reason why Dutasteride is thought to be more effective than Finasteride is that it’s able to prevent more testosterone from turning into DHT. In studies that sought to confirm these conclusions, researchers found that a sample of 399 patients who were taking a 5mg daily dose of Dutasteride experienced reduced DHT levels of approximately 98.4% +/- 1.2%.

This is in comparison to the patients who were taking a similar dose of Finasteride but only had their DHT levels reduced by 70.8% +/- 18.3%.

This study also suggested that the level of variability when taking Dutasteride is more consistent. The subjects taking Finasteride had a level of variability of 18.3%., compared to Dutasteride’s 1.2% which suggests that Dutasteride is a much more consistent drug for treating hair loss.

Finally, in another study published in the Journal of the American Academy of Dermatology [4], which involved a total of 416 men with male androgenetic alopecia (male pattern hair loss), Dutasteride treatment was also found to have a stronger effect as a hair loss treatment than Finasteride.

Why does Dutasteride work better than Finasteride?

As you can see from the studies we mentioned above, in most cases, Dutasteride was able to slightly outperform Finasteride treatment when it comes to hair regrowth, density, and thickness.

Although there is no concrete reason as to why one drug performs better than the other, the general opinion is that this is because Dutasteride (compared to Finasteride) has a longer half-life.

Unlike Finasteride’s half-life (which is around five to six hours in men aged 18 to 60 and eight hours in men 70+), Dutasteride’s half-life is around five weeks.

This means that the drug stays in the body for a much longer period of time, which could be the reason why it’s able to have much more powerful results.

It’s also important to remember that despite the fact Dutasteride performs better than Finasteride at treating male pattern baldness in most clinical trials, Finasteride is still a highly effective treatment for hair loss and has a range of trials to back up these claims. Take a look at Finasteride results (including timeline and photos) to see more.

Do Dutasteride and Finasteride have the same side effects?

Experiencing side effects from taking hair loss medication is extremely rare – especially with Dutasteride and Finasteride – but it’s still important to know what these symptoms look like in case you do notice yourself developing them.

Because of the similar nature of the two drugs, the side effects of Finasteride and the most common side effects of Dutasteride are very similar. These side effects include:

Erectile dysfunction and/or other sexual dysfunction-related problems (ex. problems with ejaculating, etc)
Hair shedding (although this effect is temporary and limited to a small amount of users)
Decreased libido
Testicular pain or discomfort
Depression
Gynecomastia (enlarged breast tissue in men)

These side effects only happen in a very small proportion of people who take either of these drugs. In fact, in clinical trials, only 1.8% of men taking Finasteride experience any side effects at all [5]. Of these, a tiny percentage may go on to experience post-Finasteride syndrome.

Prostate cancer risk

Some researchers have suggested there is a link between 5-alpha reductase inhibitors (such as Dutasteride and Finasteride) and high-grade (fast-spreading) prostate cancer [6]. However, more recent research suggests there’s no increase in the incidence of prostate cancer when using these medications [7]. However, there’s a higher chance that prostate cancer may be high-grade if cancerous cells are detected.

If you’re concerned about these side effects and the safety of these drugs, there are other options for addressing your hair loss. Learn more about other alternatives to hair transplants.

Alternatives to Dutasteride and Finasteride

Due of the nature of these drugs and their effects on male hormones, they are not suitable for those experiencing female hair loss.

If this is the case for you, or you just don’t want to take an oral medication for your hair loss, there are alternatives to Finasteride and Dutasteride available.

You can use a topical treatment, like topical Minoxidil, or you could choose something more permanent like a hair transplant. Learn more in our Finasteride vs. Minoxidil comparison.

At Wimpole Clinic, we specialise in the two most common forms of hair transplant: FUE hair transplant (Follicular Unit Extraction) transplants and FUT (Follicular Unit Transplantations).

If you want to find out more, we offer a free no-obligation introductory call that you can book at a time that suits you.