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 you experience side effects with dutasteride and decide to discontinue it, the side effects may linger for a while. This is because dutasteride, which has a longer half-life than finasteride, can take between 4-6 months to completely clear from your system, whereas finasteride usually takes just a few weeks.

Even though side effects from both finasteride and dutasteride are uncommon, they are still a possibility. If you do experience any side effects from either treatment, it's crucial to promptly communicate with your doctor about what you're experiencing.

Interestingly, some research suggests that the anticipation of side effects, known as the nocebo effect, can sometimes make them more likely to occur. Being aware of the potential sexual side effects of dutasteride could inadvertently increase their likelihood. Hence, it can sometimes be beneficial to focus less on potential side effects and more on the benefits of the medication.

Learn more: Dutasteride Side Effects and Safety — What You Need to Know

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. However, if you're dealing with an advanced stage of hair loss or if you started experiencing thinning at an early age, dutasteride might be a consideration worth exploring.

Moreover, if you've previously used finasteride and find that its efficacy seems to be diminishing, a switch to dutasteride could be a beneficial next step.

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.