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5 Most Common Dutasteride Side Effects – Should You Be Worried?
Dr Barry Abdelrahimsai (GMC)
Medically reviewed by
Dr Barry Abdelrahimsai (GMC)
Updated on April 1, 2024

As a man, it is normal to be concerned about the potential side effects of Dutasteride, especially since the most commonly reported ones concern sexual dysfunctions. Experiencing issues such as erectile dysfunction, diminished libido or difficulty ejaculating can impact your self-esteem, as well as your relationships. As can reported mood disorders, such as depression or anxiety. However, you will be glad to know that Dutasteride is considered safe for male users and only a small proportion of users report temporary unwanted side effects [1][2]. 

Dutasteride is more effective than Finasteride in curbing your hair loss and achieving significantly increased hair density [3][4][5]. When it comes to reported side effects, however, no significant difference was found between the two medications [5][3]. 

Nevertheless, if you are a woman hoping Dutasteride might help improve your female pattern baldness, things are more complex. Just like Finasteride, Dutasteride is not recommended for premenopausal women, as it can cause foetal malformations and hormonal imbalances [1]. It can, however, sometimes be safely prescribed to postmenopausal women who don’t take hormone replacement therapy.  

Keep reading this article to find out all you need to know about:

  • What Dutasteride is and how it can treat male pattern baldness
  • The most commonly reported Dutasteride side effects
  • How long you can expect Dutasteride side effects to last
  • Whether it is safe to take Dutasteride long-term
  • What your options are if Dutasteride doesn’t work for you
Table of Contents

What is Dutasteride?

Dutasteride is a drug developed for treating a condition that causes prostate enlargement (benign prostate hyperplasia). However, after men with androgenetic alopecia (male pattern baldness) started taking this treatment, they noticed that their hair shedding stopped and many of them also experienced increased hair density. 

Several clinical trials were performed, which revealed that Dutasteride is better for hair loss than Finasteride. Thus, while it has yet to be approved by the FDA for treating androgenetic alopecia, this medication is sometimes prescribed off-label for this purpose, usually as 0.5 mg Dutasteride tablets. They are most commonly sold under the brand name Avodart. 

How does Dutasteride work to treat male pattern baldness

How does Dutasteride work to treat male pattern baldness?

Dutasteride is a 5-alpha reductase inhibitor, which means it works in a very similar way to curb hair loss as Finasteride. It reduces the activity of a specific enzyme (5-alpha reductase) which converts testosterone into dihydrotestosterone (DHT), so it cannot produce too much of this male hormone. Excess DHT binds to androgen receptors in your hair follicles, preventing them from producing hair and thus triggering male pattern baldness. So diminishing DHT levels in men who have too much of it can curb hair loss and promote strand regrowth. 

Common Dutasteride Side Effects

What are the most commonly reported Dutasteride side effects?

Men who use Dutasteride for male pattern baldness most frequently report the following side effects:

1. Erectile dysfunction

Also known as impotence, erectile dysfunction is quite common, affecting on average approximately 20% of men in Western countries [6] This number significantly increases with age, affecting 60-80% of men over the age of 70. It can have numerous causes (cardiovascular issues, hormonal imbalances, psychological problems, excessive smoking and alcohol consumption etc.). Certain medications  (e.g. antidepressants) can also cause impotence. 

A major literature review [2] reveals that Dutasteride may slightly increase the risk of developing erectile dysfunction (those who take this medication are 1.2% more likely to report this condition than those who do not). That is because a considerable drop in DHT levels can have a more significant influence on some men who are more sensitive to this kind of hormonal changes. However, more research is needed, as the value is so low that it is not statistically significant (meaning it could be the result of a sample effect)[3]. This result is confirmed by several other literature reviews [7][1].

2. Decreased libido

A lower sex drive than usual can be concerning for a man. However, it is a very common occurrence, which can have physical, psychological and relational causes. It is very difficult to objectively measure libido and to determine why it fluctuates. Hormonal reasons, such as a sudden decrease in DHT, can lead to decreased sex drive. Mood disorders associated with this type of medication can also lower your libido. 

Research has found no significant difference in reported libido alteration between men who took Dutasteride for androgenetic alopecia and those who were given a placebo [6][7][1]. But if you notice this kind of effect and have reason to believe it is directly linked to Dutasteride use, it is good to know that in most cases, it resolves itself during the first year of treatment.  

3. Ejaculation dysfunction

An ejaculatory dysfunction occurs when a man ejaculates too soon, too late or is unable to do so at all. Just like the other types of sexual dysfunctions presented here, it can have numerous physical and psychological causes. 

While some of the men who take Dutasteride experience this condition, no significant increase in the number of reports has been found between them and those who do not [6][7][1].  

4. Mood disorders

Science is still working to fully decipher all the factors that influence the development of psychological conditions such as depression or anxiety. Approximately 1 in 5 people in the world experience them at some point in life. It is believed that genes, hormones, certain types of illness, certain medications, lifestyle factors, as well as significant life events can predispose you to develop them. 

Men who take Dutasteride were found to have a slightly increased risk of developing depression or anxiety compared to those who do not [3][1]. This effect tends to decrease after the first year of treatment and resolves completely in most patients after treatment is stopped. 

5. Infertility 

Studies have found that 5 alpha-reductase inhibitors such as Finasteride and Dutasteride can reduce semen volume, sperm count by approximately 25% and sperm motility by approximately 18% [4][1]. However, this effect seems to diminish with prolonged Dutasteride use.

It is still unclear whether this decrease in sperm properties has a significant impact on fertility in healthy men. However, men with a low sperm count or motility are advised to pause Dutasteride treatment when trying to have a baby.  

Can women take Dutasteride?

While in some cases, women can take Dutasteride, it is generally not recommended, especially for premenopausal patients [1]. That is because it can lead to severe foetal malformations, it can disrupt the menstrual cycle and interfere with the effectiveness of birth control medication. 

However, since studies show that Dutasteride is also very effective in reducing female pattern baldness [10], it can sometimes be prescribed off-label to post-menopausal women who are not taking hormone replacement therapy. That is because their chances of getting pregnant or experiencing Dutasteride-induced hormonal imbalances are significantly lower than those of premenopausal women. 

Dutasteride side effects for hair loss vs prostate enlargement 

When looking into Dutasteride side effects, it must be kept in mind that there are significant differences between those experienced by patients who take this medication for prostate issues and those who use it to treat hair loss. When treating an enlarged prostate, a higher dose of Dutasteride is often used, which can lead to more frequent side effects.

Moreover, patients who require this treatment tend to be more advanced in age and their health condition can sometimes predispose them to sexual dysfunctions or influence the way their body reacts to the treatment. 

Should you be worried about Dutasteride side effects?

The short answer is that most Dutasteride users needn’t worry about the rare and temporary side effects of this medication. It is true that DHT is important to male sexuality and drastically decreasing its levels can affect sexual function. However, multiple clinical trials have been performed on Dutasteride, deeming it safe in the treatment of androgenetic alopecia.

Most researchers who have studied the safety of this medicine agree that only a very small proportion of patients experience unwanted side effects. More evidence is needed to determine the nature and prevalence of Dutasteride adverse reactions since study findings can be contradictory.

Some of them find that a slightly higher proportion of patients treated with Dutasteride report side effects, in comparison to the control groups who received a placebo [2][1]. However, others find no significant increase in Dutasteride side effect prevalence when compared to the placebo group [5][8][2]

A meta-analysis performed on articles and clinical trials involving 6222 patients who took Dutasteride and 4493 patients who used both Finasteride and Dutasteride  [2] revealed no statistically significant association between Dutasteride use and increased sexual dysfunctions when compared to placebo (a similar number of men who received a placebo reported sexual dysfunctions as those who received Dutasteride, indicating that it was likely not the drug that was causing them). These results were supported by a smaller recent meta-analysis published in 2020 [7].

Why Dutasteride Cause Sexual Side Effects

Why does Dutasteride cause sexual side effects?

DHT plays an important role in the development of sexual characteristics and in maintaining sexual function. So Dutasteride can cause erection, libido and ejaculation problems in some men by drastically decreasing their overall levels of this male hormone. However, the low doses used in treating androgenetic alopecia are usually not sufficient to cause such effects and normally only do so in men who already have a predisposition towards sexual dysfunctions.

Moreover, the fact that researchers have discovered that a similar number of people in the placebo group report sexual dysfunctions as those who are taking the real medication shows that they may actually be experiencing a nocebo effect [1]. This occurs when patients are highly aware of the potential side effects of medication and concerned they may experience them. Autosuggestion makes their body develop the symptoms they were expecting or fearing.

If you are concerned you may experience Dutasteride side effects, you might want to try topical Dutasteride instead of the oral variety. While more research is needed to ascertain its efficacy, it is significantly less likely to cause systemic side effects. 

Are Dutasteride side effects temporary or permanent?

Research shows that most Dutasteride side effects occur in the first year of treatment and then significantly decline before the second one (in most people, they disappear completely) [3][4]. Moreover, in the great majority of men, all side effects resolve themselves after the cessation of treatment. This means that Dutasteride side effects are almost always temporary. 

Is it safe to take Dutasteride long term?

Yes, it is likely safe to keep taking Dutasteride in the long term. Extremely few side effects have been found to persist after the first year of use and patients have not reported the development of new ones with prolonged treatment [9]. 

What if Dutasteride does not work for me?

Dutasteride is currently the most effective medication for curbing androgenetic alopecia. If it doesn’t work for you, the best thing you can do is to book a consultation with a trichologist. That is because there are two main reasons why it would not be effective in your case. You may either have a different type of alopecia that this medication cannot treat (e.g. alopecia areata or medication-induced hair loss) or your male pattern baldness may be too advanced to be curbed by hair thinning medication alone.

The trichologist will run all the necessary tests to verify that androgenetic alopecia is indeed the reason your hair is falling out. If you receive a different diagnosis, they will recommend the most effective treatment for your real condition, such as Minoxidil or steroid creams. However, if your original diagnosis was correct and your alopecia is simply too advanced, they will assess if you are a good candidate for a hair transplant.

While Dutasteride can only help you in mild and moderate forms of male pattern baldness, you may still be eligible to get a natural looking hair transplant even if you are experiencing extensive hair loss. While the cost of a hair transplant may be higher than that of medication, you can consider it a sound investment in your future appearance. That is because medication costs keep adding up every month, while a hair transplant is permanent.

Regardless of whether you opt for FUE or FUT-type surgery, here at the Wimpole Clinic, the success rate for this procedure is almost 100%. See for yourself how your hair transplant could look after 10 years.

5 Most Common Dutasteride Side Effects – Should You Be Worried?, Wimpole Clinic

Dr Barry Abdelrahimsai (GMC)
Medically reviewed by Dr Barry Abdelrahimsai (GMC)Updated on April 1, 2024
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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