Hair loss can come in many forms; today, we will be focusing on male androgenetic alopecia, otherwise known as male pattern hair loss or baldness. This is the main form of hair loss in men, with around ⅔ of men over the age of 35 experiencing some form of thinning.

However, this isn’t the be-all and end-all of hair loss; there are medical treatments that can help you keep the hair you have. Dutasteride is one of these treatments, and is designed to help keep your hair by regulating your testosterone levels.

In this article, we will go through what you need to know about this treatment, from dutasteride’s side effects and how to use it, to how to get a prescription through our online doctor service.

Understanding Hair Loss and Androgenetic Alopecia 

Androgenetic alopecia has a few characteristic traits that make it identifiable even by the general public; the classic ‘M’ shape of the hairline, due to receding hair at the temples, and a circular patch at the crown of the head are the most common signs. This hair loss can occur any time after puberty, and usually occurs gradually over time.[1] 

The primary causes of androgenetic alopecia can be either hormonal or genetic. The hormones responsible are androgens – in particular, dihydrotestosterone (DHT).[2] 

These hormones help control the cycle of hair growth, beginning in the follicles. These are found in the skin, where each hair strand grows out for 2 to 6 years. Then, there is a resting phase for several months, after which the hair falls out. 

The cycle will repeat over time, leading to the growth of new hair. Hair thinning or loss is due to disruption of this cycle; when hair follicles are over-stimulated by androgens, this leads to a shorter growth period, in turn leading to shorter and thinner hair strands. DHT also reduces blood flow to hair follicles, which delays the production of new hair strands, and can lead to the follicles dying off over time.

Variations in the AR gene can also result in androgenetic alopecia. This gene controls the production of the androgen receptor protein. These variations result in a receptor that is more easily stimulated when androgen binds. This results in increased activity of hair follicles, leading to a faster hair growth cycle and increased hair loss.

Dutasteride’s Mechanism of Action

Dutasteride (also known as Avodart) was first manufactured to treat benign prostate hyperplasia (BPH), also known as enlarged prostate. Now, it has been shown that Dutasteride is also effective in treating male pattern baldness. It is licensed for the treatment of BPH, however, our doctors prescribe Dutasteride for its “off-label” use. 

Dutasteride is similar to another hair loss treatment called Finasteride, (Propecia being the branded version). Both medications work in a similar fashion but it is recommended to try Finasteride first before using Dutasteride.

Dutasteride works against the conversion of testosterone to DHT. It does this by inhibiting types I and II of the 5-alpha reductase enzymes that convert testosterone to DHT. Both dutasteride and propecia are 5-alpha reductase inhibitors.

Testosterone is a male sex hormone and one of its roles is to be converted into the androgen hormone, DHT. DHT reduces the blood flow to hair follicles which leads to the follicles shrinking. This reduces hair production. 

Since Dutasteride blocks this conversion, it will improve blood flow to hair follicles, thus allowing them to regain their size. This would then improve hair growth. 

Take an assessment to order Dutasteride online from £19

Comparing Dutasteride vs Finasteride 

Dutasteride and Finasteride are both used to treat hair loss. Both have a similar mechanism of action in that they inhibit the 5-alpha reductase enzyme, preventing the conversion of testosterone to DHT. However, dutasteride inhibits types I and II of the 5-alpha reductase enzymes whilst Finasteride blocks type II only. 

This means that Dutasteride would block the formation of DHT more effectively. Some studies suggest that Dutasteride can reduce DHT levels by up to 20% more than Finasteride. Finasteride is licensed to treat male pattern baldness (androgenetic alopecia), whereas the off-label use of Dutasteride is for male pattern baldness. So, it is likely that Finasteride would be used first to treat your hair loss. 

However, there is evidence that suggests that Dutasteride may be more effective at preventing hair loss compared to Finasteride. One study found that after 36 months of taking Dutasteride, 86% of men with the characteristic M-shaped hairline noticed improvement in hair growth. Whereas, only 45% of men reported similar findings when taking Finasteride. 

It is important to recognise that there is no medication that is particularly better than the other for treating hair loss; it’s unique to you. It is important to have a discussion with your GP to figure out the correct treatment for you. 

Efficacy and Considerations 

Dutasteride is an effective treatment option for promoting hair regrowth. It blocks the conversion of testosterone to DHT and results in reduced DHT levels by greater than 90% which prevents DHT’s action on hair follicles, thus preventing hair loss. 

However, Dutasteride may not be suitable for all. This medication is aimed towards males only. Do not take Dutasteride if you:

  • Are under 18 years old 
  • Have liver disease
  • Have had an allergic reaction to dutasteride, or any similar medications

Dutasteride can also cause abnormalities during pregnancy; pregnant women should avoid dutasteride, as it can be absorbed through the skin. If a pregnant woman comes in contact with dutasteride, wash the affected area immediately with soap and water, especially if the capsule is broken.

For full details about contraindications for Dutasteride, its drug interactions and warning, read Dutasteride’s UK patient information leaflet. As with any medication, there is a chance you may experience side effects:

  • Common side effects (affect 1 in 10 patients) – erectile dysfunction (ED), decreased libido (sex drive), difficulty with ejaculation, breast enlargement or tenderness (gynecomastia)
  • Uncommon side effects (affects 1 in 100 patients) – heart failure, hair loss (usually from the body) or hair growth 

For a full list of side effects of dutasteride, refer to the patient information leaflet. If any of these symptoms last for a long period of time, talk to your doctor or healthcare professional. 

Consultation with Healthcare Professionals 

It is important to talk to a healthcare professional or your pharmacist about your hair loss and potential treatment options before initiating a hair loss treatment regimen with Dutasteride. Your healthcare professional will give you specific advice tailored to you to give you the best treatment to help promote hair regrowth. Your individual health and medical history will need to be taken into account to prevent the occurrence of side effects when starting taking Dutasteride. 


  • Dutasteride is a highly effective medication used to help treat male pattern baldness (androgenetic alopecia)
  • It is important to seek professional guidance to help you make an informed decision on what hair loss treatment will work for you.
  • Addressing hair loss is a personal journey and with the right support, positive outcomes are attainable.


[1] Male Androgenetic Alopecia – National Library of Medicine

[2] Hair Loss –