Topical dutasteride for hair loss. Does it work?

To have and to have not.

 

If you are experiencing hair loss, you’ll know that hair is more than something that sits atop your head. Hair holds enormous emotional significance and is an important expression of identity and individuality.

 

Along with the eyes and smile, psychological studies have shown that hair is one of the main components of what defines someone as attractive. This influences your relationships and employment prospects. Studies have even shown that “attractive” people are less likely to be convicted of a crime. When they are, they pay lower bail.

 

Given the impacts that baldness can have on quality and ease of life, treatments for hair loss generate a lot of interest. These can include medications such as finasteride (Propecia), or surgical hair restoration techniques. Dutasteride (Avodart) is in the same drug family as Propecia.

Originally used as a treatment for an enlarged prostate, Dutasteride is a new and promising addition to the armamentarium, with a more powerful mode of action than Finasteride.

 

Though hair loss can be disruptive to life, treatments for hair loss must not be. Oral hormone-based treatments like finasteride can come with the risk of sexual side effects.

 

However, a new topical preparation of dutasteride has the potential to reduce side effects while maximising regrowth.

 

In this article, we will cover

• • The basics of pattern hair loss
  • How hormones affect hair loss
  • How dutasteride works
  • Topical vs oral dutasteride
  • Is topical dutasteride effective

What is Pattern hair loss?

Pattern hair loss, also known as Androgenetic Alopecia, affects nearly half of men over 18⁴ and around 1 in 5 women at some point in their life. Male pattern baldness is hereditary, mainly caused by a combination of age, sex hormone (androgen) and genetic factors, hence the name Androgenetic Alopecia.

 

Contrary to popular belief, hair loss isn’t caused by growth stopping altogether but by shortening of the growth (anagen) phase of hair follicles. This causes the generation of thinner hairs, in a process called follicular miniaturization. These thinner hairs fall out faster and are replaced less efficiently. This takes place over the crown, temples and frontal areas of the scalp, where we see thinning and receding of the hairline in a typical pattern.

How do hormones affect hair loss?

Testosterone and dihydrotestosterone (DHT) are the key hormones affecting hair loss. In the scalp, testosterone is converted to DHT by an enzyme called 5-alpha-reductase. DHT attaches to androgen receptors in the hair follicle and activates genes that shorten the growth phase of the hair follicle. Because of genetic variation, some people have androgen receptors that are very sensitive to DHT, while others are less so.

 

Other factors such as stress and smoking also play a part in hair loss.

 

How dutasteride works

Dutasteride, like its cousin Propecia is a 5 alpha-reductase inhibitor.

 

5-alpha reductase has two types. Finasteride works only on type 1, which is found in the liver and skin. Dutasteride works on type 1 as well as type 2, which is found in the skin and prostate, hence its original use as a drug for prostate enlargement. This makes dutasteride more powerful than finasteride.

 

By blocking the conversion of testosterone, the levels of DHT in the scalp are reduced which preserves the growth cycle of the hair follicles. Dutasteride has been found to reduce DHT levels in the blood by over 90%

 

However, this means a reduction in DHT levels in other areas of the body away from the scalp. And this can be problematic.

 

Why?

 

Well, DHT is an androgenic hormone and acts like a potent version of testosterone, around 2-3 times more powerful than testosterone, performing sexual and physiological functions around the body, such as regulating androgen levels and sexual function. This means that side effects can include erectile dysfunction, difficulties ejaculating and even depression and anxiety. In one study, oral dutasteride led to sexual side effects in 13% of men.

 

 

Topical dutasteride vs Oral dutasteride

While dutasteride can be an effective treatment for hair loss, this is an “off-label” use, meaning it hasn’t been officially approved for this purpose and less information is known about its safety and side effects in this context.

 

Topical forms of dutasteride are applied directly to the skin. This means that the action of the drug is mostly localised to the scalp, which can reduce, but not eliminate the risk of unpleasant side effects. Because the drug can still be absorbed into the scalp and then into blood vessels, topical dutasteride can still be associated with side effects though this is likely to be much lower than the tablet form.

 

Topical dutasteride has fewer systemic side effects

Research into the absorption of 5 alpha-reductase inhibitors found that peak concentrations of the drug were around 15 times lower in the blood when used topically versus orally. In a review of topical versus oral finasteride, topical finasteride was found to reduce the potential for side effects, with most being localized to the scalp.

 

From these studies, we can assume that used topically, dutasteride shares the same properties. It can be absorbed by the skin, and work locally on the scalp, with lower systemic absorption and fewer side effects as a result.

 

 

Is topical dutasteride effective

Research has shown that dutasteride can effectively treat hair loss when used orally. In one analysis of multiple studies, 0.5mg of oral dutasteride was found to be the most effective at changing total and terminal hair count at 24 and 48 weeks compared to high-dose oral finasteride and oral minoxidil.

 

Because topical dutasteride is a relatively new compound, there are fewer completed studies that look at how effective it is in pattern hair loss used alone.

 

Most studies of topical dutasteride look at its effectiveness in combination with micro needling or mesotherapy, where the drug is injected into the skin of the scalp. This could be because dutasteride is a large molecule compared to finasteride and is harder for the skin to absorb as a result. Research involving 0.05% dutasteride solution combined with mesotherapy showed an improvement in 62.8% of female patients and up to 92.9% of male patients. 

 

In a study of 30 men, patients who received microneedling and 0.02% topical dutasteride solution had significant increases in hair calibre and terminal/vellus hair count compared to those who received microneedling alone. The dutasteride group also had increased investigator and participant-assessed scores of satisfaction and hair regrowth.

 

An exploratory study on the safety and effectiveness of topical dutasteride alone is currently underway.

 

Topical dutasteride, what’s the deal?

 

Topical dutasteride is a new and exciting treatment option for pattern hair loss.

 

Though we are still waiting for the publication of definitive evidence that it is effective, there is research underway and what we do know is encouraging.

 

• Dutasteride is a more potent version of finasteride. It is able to reduce DHT levels more effectively than finasteride because it works on both forms of the 5 alpha-reductase enzyme.
• Dutasteride used orally is more effective than finasteride at treating hair loss and at lower doses.
• Dutasteride can be absorbed by the skin.
• Topical dutasteride has a lower potential for absorption into the bloodstream versus oral dutasteride. This can reduce the risk of side effects in the body while still maximising its effect on the scalp.

 

Combining these points, we can be confident that topical dutasteride is a promising new addition to the hair loss armory.