Finasteride vs Dutasteride for Hair Loss

The most commonly prescribed treatment available today for male pattern baldness is finasteride (Propecia). While finasteride is enough to stop hair loss for most people, dutasteride (Avodart) can be a good alternative for hair loss patients looking for a more effective solution.

What is Dutasteride (Avodart)?

Dutasteride was initially a drug meant to treat enlargement of the prostate (benign prostatic hyperplasia, BPH) under the brand name “Avodart”.

It works in a very similar way as finasteride. They are both designed to stop the conversion of testosterone into dihydrotestosterone (DHT), a hormone that causes male pattern baldness.

While finasteride is approved for the treatment of hair loss, dutasteride is not. So far, dutasteride has only been approved for BPH. That doesn’t mean it’s ineffective at treating hair loss, just that the drug has not been specifically tested by the drug company for this condition. Many of the studies out there have only tested dutasteride on an older population of patients (with prostate disease) rather than young patients needing medical treatment for hair loss.

And since the patent for dutasteride has already expired, drug manufacturers have little incentive to go through the hassle of approving it, so we will most likely never see dutasteride approved for hair loss.

It is interesting to note that dutasteride has been approved to treat hair loss in Asian countries like Japan and South Korea. In fact, Avodart is prescribed more than Propecia to hair loss patients in these countries every year.

What’s the Difference Between Dutasteride and Finasteride?

The main difference between dutasteride and finasteride is the intensity of the effect. Finasteride 1mg blocks about 70% of DHT, whereas dutasteride 0.5mg blocks more than 90%. This means that dutasteride is more effective at stopping the conversion of testosterone into DHT. Since DHT is what causes hair loss, this results in more hair regrowth and thickening of existing miniaturized hairs compared to finasteride.

One American study compared the effects of dutasteride, finasteride, and placebo in 416 young men experiencing hair loss. After 24 weeks, dutasteride significantly increased total hair count and hair width, followed by finasteride. As expected, the placebo group kept losing hair. Hair counts are shown in the table below:

Note that the finasteride dose used above is the higher dose used to treat BPH (5mg vs 1mg). Nonetheless, dutasteride still produced better hair growth than the counterpart.

Another study on 917 men showed similar results based on hair counts and photographic assessments.

A more recent study conducted a review of all finasteride and dutasteride studies treating MPB, published between 1990 and 2018. They concluded that dutasteride is more effective at treating hair loss and shows similar rates of adverse reactions, especially in sexual dysfunction.

Dutasteride Side Effects

Just like finasteride, dutasteride users may experience sexual side effects like decreased libido, erectile dysfunction and problems ejaculating. However, these are rare and generally reversible.

Study data shows that dutasteride is generally safe and well-tolerated, even at the higher doses used to treat BPH.

The table below, taken from another study, shows that the differences between the two drugs in terms of side effects are marginal.

It’s worth noting that if side effects do happen with dutasteride, and you decide to stop, it may take longer for side effects to disappear. This is because dutasteride has a longer half-life than finasteride. It takes 4-6 months for dutasteride to completely get out of your system, whereas finasteride takes weeks.

While side effects from finasteride and dutasteride are rare, they can still happen. If you experience side effects from either treatment, talk to your doctor and let them know about your experience.

With that said, some studies show that side effects could in some cases be due to a nocebo effect. In short, knowing about the sexual side effects of dutasteride could make them more likely to occur. Sometimes it’s best to just take the medication and not think about it too much.

What to Expect When Taking Dutasteride for Hair Loss

As with finasteride, dutasteride effects can start to be seen 4-6 months after starting the medication. Most men will notice less hair fall and more hair regrowth during this period. Patients taking dutasteride should be on the medication for at least 1 year before its effects in preventing hair loss and re-growing hair can be accurately assessed.

During the first few months on dutasteride, one may note some thinning of existing hair. This may be due to either progression of your hair loss before dutasteride has had a chance to work, or some shedding of miniaturized hair that makes way for the new healthy hair to grow. It is important to be patient during this period. You should continue the medication for at least one year before you and your doctor can assess its benefits.

The Bottom Line

We generally recommend finasteride as the first line of treatment for hair loss. If you have an advanced case of hair loss or have started thinning at a young age, you may wish to consider dutasteride.

You may also wish to switch to dutasteride if you've been on finasteride in the past and notice that it's starting to lose its effect.

How to Get a Dutasteride or Finasteride Prescription in Canada

You can get a hair loss prescription online by having a Canadian licensed doctor diagnose your hair loss through Essential Clinic. We offer both dutasteride and finasteride prescription options to patients, depending on your preference and doctor recommendation.

Ready for your hair loss treatment? Get started with your online visit.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.