Hair loss

Dutasteride vs Finasteride: What’s Best for Hair Loss?

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Medically approved by Dr Earim Chaudry
Chief Medical Officer
iconLast updated 7th January 2022
In 30 seconds…

Dutasteride and Finasteride are two drugs that can be used to treat hair loss in men. Where Finasteride is approved by the US Food & Drug Administration (FDA) for the treatment of male pattern baldness, though, this is not yet true for Dutasteride.

Finasteride has been around for a while longer – and there is more scientific evidence behind it. Nonetheless, both drugs are 5-alpha reductase inhibitors. As such, they block the enzyme responsible for the production of DHT – the hormone that causes male pattern baldness. Both are generally well tolerated, while Dutasteride appears to be more effective in reducing DHT levels.

However, for the treatment of male pattern hair loss, it is generally best to use Finasteride. Reliable, approved as safe, and readily available in the UK, it is currently a lot more trustworthy than Dutasteride right now.

Introducing Finasteride and Dutasteride

Two of the most powerful drugs for reducing your levels of DHT, Dutasteride and Finasteride are often discussed together. There are good reasons for this. Targeting the same biological process and having similar chemical structures, they do share a number of benefits.

However, given their different histories and uses, there are some key features that distinguish the two drugs, too. And while many people suggest that both can be used for the treatment of androgenetic alopecia – or male hair loss – we do have an obligation to be precise when talking about medicines.

So, Finasteride and Dutasteride – what are the differences? And can both really be used to encourage hair growth? Let’s take a look at the science and history of each drug.

What is Finasteride?

Finasteride is a highly effective treatment for male pattern baldness (MPB) – and, with the exception of Minoxidil, it is the only medical treatment that is approved for this purpose. Often sold under the name Propecia, it was also the first drug available to be classed as a 5α-Reductase inhibitor.

Finasteride’s fight against MPB starts by tackling 5α-Reductase, the enzyme responsible for the conversion of testosterone into dihydrotestosterone (or DHT). This is crucial – as it is DHT that is at the root of the biological cause of MPB. In many men, hair follicles are sensitive to the hormone, and, when it accumulates in the body, your follicles become weaker, smaller, and less able to produce hair. As a result, they can stop producing hair entirely.

Initially trialled as a treatment for benign prostatic hyperplasia (BPH, or an enlarged prostate gland), Finasteride was found in trials to produce unwanted hair. As a result, it was soon licenced as a treatment for MPB.

What is Dutasteride?

Dutasteride – often sold under the brand name, Avodart – is a 5α-Reductase inhibitor just like Finasteride. However, it has never been licenced as a treatment for MPB. Rather, like Finasteride again, it was designed as a treatment for BPH. It has been approved by medical bodies in the UK and US for this purpose – and is still used as such today.

In the same way as Finasteride, Dutasteride prevents your body from metabolising testosterone into DHT. However, on this count alone, Dutasteride may well be more effective than its older brother. According to one small study from 2004, where a 5mg Finasteride dose reduced DHT levels by 70%, Dutasteride reduced levels of the hormone by a massive 98.4%.

Finasteride or Dutasteride: Which is More Effective for Treating Hair Loss?

Dutasteride vs Finasteride: now we’ve met the contenders, which is most likely to help hair loss? Knowing that Dutasteride has a more radical effect than Finasteride on DHT, you would expect it to have the edge.

You wouldn’t be wrong. One 2006 study comparing the two drugs found that Dutasteride treatment resulted in slightly better hair coverage than its alternative. More recently, a meta-analysis from 2019 – in which researchers reviewed the findings of a number of previous studies – found similar results.

As the researchers observed, the findings suggest that it all comes down to DHT levels. When treating MPB, tackling these are crucial.

Comparing the Side Effects

Like all medicines, Finasteride and Dutasteride both have their potential side effects. Yet, in the case of these 5α-Reductase inhibitors, even the vanishingly rare side effects have received a lot of publicity.

This is because there have been quite serious cases, such as issues with sexual dysfunction. These reported sexual side effects have included erectile dysfunction, problems with ejaculation, and a loss of libido. And the milder side effects – including breast tenderness, dizziness, and change of weight, for example – are rare too. In clinical trials, the proportion of patients taking Finasteride who did not experience any side effects at all was 98.6%. Similar numbers are true of Dutasteride.

To sum up, then, while adverse effects are possible with both Dutasteride and Finasteride, you can be assured that these are rare.

Finasteride vs Dutasteride: Which is Best for Treating Hair Loss?

While Dutasteride appears to be slightly more effective in treating hair loss, professional medical advice would advise the use of Finasteride. We would have to agree.

Why? Because while there may not appear to be any significant differences between the two treatment options, we do not yet know enough about Dutasteride. As we said, it has not been approved for the treatment of MPB in the UK or the United States – and no British trial has ever confirmed its efficacy for hair loss treatment.

Simply enough, Finasteride is just more trustworthy at this time. Yet, the prospects for Dutasteride are good. Seemingly more effective and with a very similar tolerability profile to Finasteride, it may well be a future favourite for the treatment of male pattern baldness.

Key Takeaways

Which is better for the treatment of hair loss, then, Finasteride or Dutasteride? According to the studies available, Dutasteride may be more effective for increasing your hair count. However, with the approval of the US FDA and the UK medical authority behind it, Finasteride remains the most reliable choice.

Unfortunately for Dutasteride, as it is unlicensed, you just cannot be sure of its safety. The future, however, looks bright for the use of this drug for MPB, nonetheless.


Elise A Olsen , Maria Hordinsky, David Whiting, Dow Stough, Stuart Hobbs, Melissa L Ellis, Timothy Wilson, Roger S Rittmaster (2006). The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride: 


Zhongbao Zhou, Shiqiang Song, Zhenli Gao, Jitao Wu, Jiajia Ma, and Yuanshan Cui (2019). The efficacy and safety of dutasteride compared with finasteride in treating men with androgenetic alopecia: a systematic review and meta-analysis:


Ian M. Thompson, M.D., Phyllis J. Goodman, M.S., Catherine M. Tangen, Dr.P.H., M. Scott Lucia, M.D., Gary J. Miller, M.D., Ph.D., Leslie G. Ford, M.D., Michael M. Lieber, M.D., R. Duane Cespedes, M.D., James N. Atkins, M.D., Scott M. Lippman, M.D., Susie M. Carlin, B.A., Anne Ryan, R.N., Connie M. Szczepanek, R.N., B.S.N., John J. Crowley, Ph.D., and Charles A. Coltman, Jr., M.D. (2003). The Influence of Finasteride on the Development of Prostate Cancer:


While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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