Avodart For Hair Loss – The Pros and Cons of Using for Regrowth

  • Medically reviewed by: Dr. Anil Simhadri
  • Written by: William Slator
  • Last updated: 09/01/2024

Avodart regrows hair by blocking DHT. It is actually the most powerful DHT-blocker on the market, even stronger than finasteride.

However, there can be severe side effects associated with it, and as soon as you stop using it all the hair you regrew (and more) will fall back out.

This article will explain the pros and cons of using Avodart. We will also look at how the drug compares to finasteride. In consultation with your doctor, you can then see if this is the right treatment option for you.

What is Avodart?

dutasteride capsules
Dutasteride capsules. Photo by melvil / CC BY

The active ingredient in Avodart is dutasteride. GlaxoSmithKline originally developed it to treat the symptoms of BPH, or benign prostatic hyperplasia, also known as an enlarged prostate.

Prostate enlargement is a very common condition with old age. It can affect close to half of men who are 50 years old. Symptoms include difficulty urinating, the need to urinate more often, and poor sleep. Dutasteride can reduce the size of the prostate and relieve the symptoms of BPH.

Since 2009, Dutasteride has also been approved in South Korea to treat androgenetic alopecia (AGA), also known as male pattern hair loss.

However, the FDA never approved it as a hair loss treatment in the United States. Doctors, therefore, prescribe it off-label to their balding male patients. Its use with women is very uncommon.

Dutasteride’s patent has now expired. This means that in addition to the branded Avodart, you can also source generic versions for a fraction of the price.

How Does Dutasteride Help with Hair Regrowth?

DHT & Hair Loss


Men who suffer from male pattern hair loss or BPH both have a sensitivity to dihydrotestosterone (or DHT).

DHT is one of the four male hormones that make up the androgen family. The other three are testosterone, androstenedione, and dehydroepiandrosterone. Out of these four hormones, DHT is the strongest, with a potency in the male body about three times that of testosterone (1).

When a male starts out his life as a fetus in the womb, he needs DHT to develop the male sex organs. Without DHT the male reproductive organs will not develop, so this is obviously a crucial hormone.

Shortly after birth, the production of DHT drops to undetectable levels. But during puberty, DHT is once again critical for the development of the so-called secondary sex characteristics, like the bodily hair on the chest and other parts of the body, the deepening of the voice, as well as musculoskeletal changes, and more.

It is after puberty that DHT apparently stops doing anything useful and starts to create problems. The two main problems it causes are a) the enlargement of the prostate, and b) male pattern baldness.

It is no coincidence that dutasteride and finasteride are effective against both these conditions.

Avodart’s Mechanism of Action

DHT is converted from testosterone via the action of two different enzymes. These two enzymes are different in molecular structure but identical in function. Scientists call them 5-alpha-reductase type I and 5-alpha-reductase type II.  Without at least one of these enzymes, our body cannot create DHT.

Avodart blocks the action of both 5-alpha-reductase enzymes. The dutasteride molecule binds to either of these two enzymes and forms one large drug-enzyme complex. This molecule is very stable over time, and it serves to trap the 5-alpha-reductase molecules in it.

When they are bound to dutasteride, the enzymes cannot convert testosterone to DHT, and the production of DHT in the body drops dramatically.

How Effective Is Avodart?

Although the drug is not approved in the US to treat male pattern baldness, many studies have been performed to find out how effective Dutasteride is in treating hair loss (2).

Twin Studies

A study published on PubMed.gov in 2007 compared the effectiveness of Dutasteride in the treatment of male pattern hair loss on identical twins. Seventeen pairs of twins were used in the study that took place over one year (3).

In the randomized, double-blind, placebo-controlled study one twin received 0.5mg of Avodart each day for 12 months while the other twin took a placebo.

The researchers looked at hair growth using before and after photos, hair counts, and patient surveys.

Over a year, dutasteride improved the hair growth of the men taking the drug compared to their identical twin brothers who took the placebo.

Sixteen out of the seventeen sets of twins who participated in the study could easily determine who took the real drug and who took the placebo.

Versus Placebo

Another study performed in 2010 looked at the efficacy, safety, and tolerability of Avodart 0.5mg. The goal of this trial was to look at the effects of the drug as well as how effective it was in treating male pattern hair loss (4).

153 men between the ages of 18 and 49 took part in the study. They randomly received 0.5mg of Dutasteride or a placebo for six months. Scientists looked at changes in hair counts, subject assessment, and before and after images.

Those who took Avodart during the six-month trial had a significant improvement in hair density.

Comparison To Finasteride

Dutasteride is a much more powerful 5-alpha reductase inhibitor than the leading hair loss treatment Propecia (active ingredient finasteride).

While Propecia only inhibits the type 2 enzyme, we saw that Avodart inhibits type 1 as well. On paper, this suggests that it should be more effective at regrowing hair. Is this true?

A meta-analysis comparing the efficacy of dutasteride vs finasteride for male pattern hair loss was published in 2019 (5). A meta-analysis is like a scientific review of individual research reports. Its findings are generally more important than any single piece of clinical research in isolation.

The authors of this metanalysis found three randomized, double-blind trials that directly compared the effects of dutasteride to finasteride.

Across the 3 studies, a total of 290 patients were treated with dutasteride and 286 with finasteride.

The efficacy parameters the metanalysis looked at were a) change in hair count, b) investigator assessments of the before and after photographs c) assessments of the photographs by a panel of experts, as well as d) the subjects’ own assessment of the treatment efficacy. The results of the meta-analysis showed that dutasteride was statistically superior to finasteride in all respects.

The results of the metanalysis showed that dutasteride was statistically superior to finasteride in all respects.

With regards to sexual side effects (which we will come to shortly), the metanalysis found no statistically significant difference in their frequency between the two treatments.


What Do Patients Say?

With dutasteride on the market for several decades already, there are plenty of user testimonials online. Positive points commonly mentioned in these are hair growing back thicker and fuller, few side effects, and reduced body hair growth.

Unfortunately, other users say that they have experienced side effects. The most common are a low sperm count, issues with their libido, and more. We will review the side effects shortly.

Many experienced no good or bad effects at all. They still had thinning hair even after taking the drug each day for months.

Overall, most men in the hair loss community agree that Avodart is more effective than Propecia.

How Long Do Results Last?

Like finasteride, results with dutasteride only last as long as the treatment. As soon as you stop treatment, the levels of DHT in your blood will rise again, and hair loss will resume.

On average, you will lose any hair you might have regrown within 6 months of stopping treatment. If your underlying pattern of hair loss has progressed while you were on the drug, this will also become evident. The result is that your hair might be worse than before you started treatment.

For these reasons, it is important to start treatment only if you are determined to stick to it for the long run. Avodart is not a baldness cure. Think of it instead as a long-term hair loss management medication.

avodart, dutasteride, DHT blocker
Results on Avodart only last as long as treatment.

Potential Dangers

Because their mechanism of action is very similar, the side effects of dutasteride are very similar to finasteride. The most common ones are impotence, a decrease in sex drive, ejaculation problems, and gynecomastia (6).

The drug can also sometimes reduce sperm count, the volume of semen produced, as well as the mobility of the sperm cells. These reductions are mild, but they will affect most users of the drug. Here is a list of the most common side effects:

  1. Impotence
  2. Low Libido
  3. Difficulty achieving orgasm
  4. Irregular ejaculation
  5. Low Testosterone
  6. Low Sperm Count
  7. Decreased energy
  8. Decreased muscle mass
Erectile dysfunction is a possible dutasteride side effect.

Often, these side effects will resolve on their own. Other times, however, they will persist. In this case, the only option is to discontinue treatment.

If you experience any side effects while on dutasteride, the first thing to do is speak to your doctor. Do not start, stop or modify your dutasteride dosage unless your doctor instructs you to do so.

How Can I Get Avodart?

For reasons that are not entirely clear, the makers of Avodart never marketed the drug for hair loss in the United States. This is even though, as we saw, it is slightly more effective than finasteride, and will roughly have similar side effects.

The drug is only sold in the US for prostate enlargement, though many doctors prescribe it off-label to their balding patients.

Since the drug’s patent has now expired, there is no incentive for GlaxoSmithKline (GSK) to spend millions of dollars pursuing marketing authorization for hair loss. As there are countless cheaper generic versions on the market, there is simply no financial incentive for GSK to spend any more money on researching dutasteride.

Unlike finasteride, dutasteride will never be sold for the indication of hair loss.

This does not mean that you cannot use it, however. It is perfectly legal for your doctor to prescribe Avodart to you off-label for your hair loss on request. Together, you can discuss the pros and cons of taking Avodart, and see if this is the right option for you.

The Bottom Line

Multiple clinical trials have confirmed that Avodart is a powerful alternative to Propecia in terms of halting hair loss in men. Nearly 90% will halt the progression of their hair loss, and most of them will also see some mild regrowth. This will typically be slightly superior to what they would get from finasteride, though not by much.

For one reason or another, the makers of Avodart never marketed it for hair loss. This means that if you want to use it to treat your hair loss, you will need a doctor’s off-label prescription.

In common with other 5-alpha-reductase inhibitors, most notably finasteride, dutasteride can have unpleasant sexual side effects. These will often resolve on their own. If they do not, your only option will be to discontinue treatment.

Your doctor will be able to advise you on the benefits and risks of taking Avodart for your hair loss, as well as the management of any side effects.

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