It cannot be denied that dutasteride is the most effective 5 alpha reductase inhibitor in existence to date and as such the potential for treating baldness would be truly remarkable. However, if you are on a high dosage you can run into side effects that are not very easy to manage due to the long half-life. If, on the other hand, you opt for too low a dose, at this point I don’t see any particular advantages over finasteride.

In the end it is necessary to find the optimal dose together with the doctor who eventually prescribes dutasteride for the hair .

To conclude, my personal opinion is that, except in cases in which the answer is little to fine and you want to try with the greater potency of Avodart, to date we already have finasteride as an anti dht drug with a specifically approved dosage for baldness therefore, in my opinion, the game is not worth the candle.

As always, I strongly advise against do-it-yourself since we are talking about a drug that is anything but light and taking it when it is not necessary or mistaking the dosages by self-healing can have annoying consequences.

If you want to tell about your experience with Avodart, or would like to ask a few questions, do not hesitate to leave a comment in the appropriate box at the bottom of the page.


You will have noticed that usually on helphairless the drugs we are talking about are those approved for the treatment of androgenetic alopecia, while dutasteride to date is not yet. And this not only in Italy, but not even in Europe and the USA as both the American FDA and the European EMA have granted authorization for the treatment of benign prostatic hypertrophy or BPH only.

So why this exception to the rule? The answer is quite simple and is first and foremost linked to the numerous requests received from readers. Furthermore, by investigating this drug to prepare the article you are reading, I verified that dutasteride has been approved for the treatment of androgenetic alopecia in South Korea since 2009 and since September 2015 also in Japan .

So, in my view, it deserves to be treated among the possible pharmacological remedies to combat male pattern baldness.

Patented in 1996 by GlaxoSmithKlein (GSK) and marketed under the name of Avodart , it was created, as already mentioned above, for the treatment of symptoms related to benign prostatic hyperplasia.

How does it work?

Dutasteride is a 5-alpha reductase enzyme inhibitor whose purpose in the body is to convert the male hormone testosterone into dihydrotestosterone (DHT) . In fact, the drug reduces the production of DHT which is known to be one of the main causes of BPH.

It is among the second generation 5-alpha reductase inhibitors since it acts on both isoforms 1 and 2 unlike finasteride which acts exclusively on isoform 2 of this enzyme.

So already on paper it seems to have a greater inhibitory action compared to finasteride and in fact it has proved to be 3 times more powerful in inhibiting type 2 5-alpha reductase and up to 100 times on the isoform 1. This translates into a killing capacity up to over 90% of serum dht versus 60-70% of finasteride.

Dutasteride and Capelli: can it be useful?

We have seen how this drug is useful for treating benign prostate enlargement by preventing the conversion of testosterone into dihydrotestosterone and we know how this hormone is also among the main factors that cause the miniaturization of the hair follicles present in the scalp of people affected by androgenetic alopecia. .

In practice it acts in a similar way to finasteride (which is approved for baldness) as well as to serenoa repens (the most valid of the natural antidht supplements).

Except that the action of dutasteride is decidedly more powerful than these, reaching levels of abatement close to 94% as we have seen from the graph above.

Most of the studies carried out concern the treatment of the prostate while those on androgenetic alopecia are not many.

I found this  study 1) published in the Journal American Academy Dermatology made in Korea in 2006 which attested the efficacy of avodart at various dosages (from 0.05 to 2.5 mg day) on Androgenetic Alopecia. Then in 2009 it was approved at the same dosage as for the prostate, which is 0.5 mg per day.

Also Korean  study 2) following the approval for AGA published in the sector journal Annals of Dermatology carried out on 712 men affected by androgenetic alopecia at various degrees of the norwood scale whose duration lasted for a period of 4 years from 2009 to 2013 . If you are unfamiliar with English, in a nutshell it says that it is well tolerated at a dosage of 0.5 mg per day and the incidence of side effects is limited. Most of the (few) side effects resolved upon discontinuation of the drug and in the link to the study everything is reported in detail. But this is not the section to talk about dutasteride side effects, you will find it later in this article 😉

So from a first reading it would seem that there is no lower dose for the hair (as was done with Propecia 1 mg compared to Proscar 5mg for the prostate) and honestly this can be perplexing.

But I must admit that finding information on the dosages used in the countries where it is approved is not easy, perhaps because they are oriental and therefore outside the European and American circle. However, looking on the net I was able to find the Zagallo drug always produced by GlaxoSmithKlein (GSK) for the Japanese market where dutasteride is also approved for baldness and with pleasure I noticed that it is available in 2 dosages. There is in fact the classic 0.5 mg format, however, as you can see in the image, there is also a 0.1 mg version .

And in the Zagallo 0.1 mg data sheet we talk about androgenetic alopecia , so it seems to have come to the logical conclusion that the dosage for the prostate is probably too high for baldness. Hence the reduced dosage drug which unfortunately is not available here.

However, I will soon publish an article that will specifically deal with dutasteride dosage and comparison with finasteride .

Directions for use

Avodart and its generic counterparts are marketed in the form of softgels , i.e. soft capsules composed of a soft gelatin shell inside which the active ingredient is contained in liquid form .

The official dosage in Italy is provided only for the treatment of prostatic hyperplasia and is equal to 0.5 mg per day which correspond to a softgel.

For AGA, not being approved, there is no official dosage and, for those wishing to have it prescribed off label by their doctor, it is advisable to carefully follow the indications provided by it as as we will see, the side effects can be quite annoying.

To overcome the dose problem, you might think of dividing the softgel into several parts as is done in the case of those who use Proscar instead of Propecia (breaking it into 4 or 5 parts). However by its nature the soft capsule is not divisible as the active principle is in liquid form.

Dutasteride Side Effects

It is always important to point out that ALL drugs can cause unwanted effects , even those of the most common use. But this does not mean that they manifest themselves in anyone who uses them, on the contrary, it is good to consider them as a rare and unfortunate occurrence .

However, since it is a 5 alpha reductase inhibitor, any side effects are the same that can cause drugs in this category and, just so as not to bring the Avodart leaflet back to par, I will limit myself to mentioning the main ones:

  • They range from common effects (i.e. seen by 1 in 10 individuals) such as those of a sexual nature such as erectile dysfunction, reduced libido, difficulty in ejaculation and decreased quantity of seminal fluid. This type of side also includes gynecomastia , that is, the enlargement of the mammary gland in humans.
  • Among the uncommon effects (i.e. seen by 1 in 100 individuals) was the loss of body hair, due to the variation of androgens
  • Finally, immune reactions should not be excluded since, as with any type of drug, any allergies or hypersensitivity to the active ingredient that could lead to more or less severe allergic reactions must be considered .
  • However, given its greater ability to inhibit DHT and above all to act also on the isoform 1 of the enzyme, present above all at the level of the brain and nervous system , it could act more at the level of cerebral neurosteroids giving rise to the famous brain fog which consists, as you can understand by translating the name, in a sort of “brain fog” that manifests itself in the form of difficulty in concentrating. However, it is a very rare and controversial side as there are no serious studies that prove it.
  • As for the hair , many users have found an excessive “dryness” and a sort of “straw effect” due to the strong reduction in sebum production. This would be a direct consequence of the inhibition of type 1 5-AR whose concentration is significant in the sebaceous glands.

However, it should be remembered that most of the side effects of dutasteride regress upon discontinuation of the drug , or rather after some time as I will explain shortly.

Very long half-life time

One factor to consider is the half-  life of about 4 weeks which is considered to be extremely long. This is the time it takes for the concentration of the drug in the body to halve . Suffice it to say that that of finasteride is about 6-8 hours.

Hence my doubts also regarding side effects since, as you can see from the graph below, it is clear that disposal is very slow after the suspension. And it may not be pleasant if you are hit by sides because even after a month of stop, we will still have a significant amount of active ingredient in circulation.

Here is the graph that, in addition to the greater suppression of dht compared to finasteride, also shows how long it takes to “dispose of” the drug after discontinuing the intake:

In short, to be truly “clean” it can take up to 6 months!


It is good to evaluate the intake of the drug together with your doctor in case you suffer from liver failure . This is not because there are studies that attest to its dangerousness, but at a preventive level because, given that dutasteride is metabolized in the liver , it is not suitable for people whose liver function is not normal.

Warnings and Precautions


Given that 5-alpha reductase inhibitors can have harmful effects on the fetus that could manifest malformations of the reproductive organs, pregnant women must strictly avoid contact with Dutasteride.

Even just touching a capsule could be risky for the fetus as the drug can also be absorbed through the skin . For the same reason, children and adolescents must also avoid coming into contact with them.

Unprotected sexual intercourse should also be avoided since traces of dutasteride are also found in seminal fluid .

Even blood donations from those who take the drug should be made after at least six months of interruption to prevent possible transmission to pregnant partner.

PSA monitoring

Finally, as with finasteride, dutasteride causes a 50% reduction in serum concentrations of prostate specific antigen (PSA) , used as a screening for the diagnosis of prostate cancer (together with rectal examination). The drug can therefore distort the diagnostic indication of this marker and it would therefore be good to suspend it with at least 2 months in case of analysis, or when informing the doctor who is taking it.

Interactions with other drugs

As we have seen, Avodart and equivalents are metabolized by the liver and more particularly thanks to the CYP3A4 enzyme. Therefore it is necessary to pay attention in case you are taking drugs inhibitors of CYP3A4 such as ketoconazole , itraconazole , Ritonavir and Indinavir (antivirals used for example in the treatment of AIDS), nefadozone (antidepressant), etc …

This is because these drugs reduce the amount of the enzyme capable of transforming dutasteride and therefore it could be found to have a higher concentration than desired with a consequent greater appearance of side or unwanted effects.

Dutasteride: where to buy?

GSK’s patent expired in 2015 and therefore, in addition to the aforementioned Avodart, the first drugs based on generic dutasteride or equivalent produced by pharmaceutical companies of absolute importance such as Teva , Mylan , are beginning to appear on the market . Sandoz , EG and others less known.

In any case, it is mandatory to purchase from a pharmacy with a medical prescription which can be made either with a red prescription for the treatment of benign prostatic hypertrophy, or with a white prescription (off label). But always and in any case by a doctor, as I stress again that the side effects can be strong given the potency of the drug.



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