What is Dutasteride?

You might have heard about the latest breakthrough in treating hair loss in men, dutasteride. Think of it as a kind of big brother to a similar medicine used for male pattern hair loss, finasteride. But before we delve into the exciting results that dutasteride demonstrates with regard to hair loss, let’s give you a breakdown of what is contained in this article.

What is androgenetic alopecia?

Androgenetic alopecia (AGA), also known as male pattern baldness, is a common condition where genetics play a significant role in causing hair to thin and recede over time. In men, this typically shows up as a receding hairline and thinning of hair on the scalp, leading to progressive hair loss [1].

Androgenetic alopecia (AGA), also known as female pattern hair loss, is marked by gradual hair thinning in women. Unlike men, women usually don’t see their hairline receding; instead, they experience an overall hair thinning across the scalp [2].

What causes androgenetic alopecia?

The main reason androgenetic alopecia (AGA) occurs is that an enzyme called 5?-reductase turns testosterone into another hormone called dihydrotestosterone (DHT). This DHT then attaches to specific receptors in hair follicles, disrupting essential signals for hair growth. As a result, the cells responsible for hair growth don’t work either, leading to thinner hair or hair loss [3].

Over time, hair follicles that are genetically prone to hair loss start to shrink, and the normal, thick hairs they produce are replaced by much finer, thinner hairs [4]. As this process unfolds, the natural hair growth cycle also changes: the growth phase (anagen) becomes shorter, while the resting phase (telogen) gets longer. Since the growth phase determines hair length, the hairs that grow end up shorter. Over time, this results in shorter hair and increasingly noticeable bald spots [5].

The types of the enzyme 5-alpha reductase

There are three types of the enzyme 5-alpha reductase: type 1, type 2, and type 3. Types I and II are found in the scalp of people with androgenetic alopecia (AGA) [6], and type III has been found in actively growing (anagen) hair [7].

Two medications, dutasteride and finasteride, block this enzyme and are known as 5-alpha reductase inhibitors (5ARIs). Currently, only topical minoxidil and oral finasteride are FDA-approved for treating AGA or male pattern baldness. The FDA has approved dutasteride for treating benign prostatic hyperplasia (BPH) at a dose of 0.5 mg per day [8], but only South Korea and Japan have approved its use for androgenetic alopecia or male pattern baldness [9,10].

Why does dutasteride cause a more significant reduction in DHT levels

Dutasteride is a dual inhibitor of 5-alpha reductase isotypes 1 and 2 (used for treating benign prostatic hyperplasia) and, therefore, can decrease DHT levels to a greater extent than finasteride, which is a selective isotype 2-inhibitor.

 A study performed by Gubelin Harcha et al. demonstrated the efficacy and safety of 0.5mg dutasteride in increasing hair growth and restoration in men with androgenetic alopecia [1].

In another study by Jung et al., 0.5mg dutasteride /day proved effective in men with male pattern baldness resistant to finasteride [2].

The plasma half-life of dutasteride (3-5 weeks) is significantly longer than that of finasteride (age-dependent from 5 to 8 hours). If you are unsure what the term plasma half-life means, read the following section. Otherwise, if you already know, you can skip to finasteride versus dutasteride.

What is the plasma half-life?

Plasma half-life is a term used in pharmacology (the science of drugs) to describe how long it takes for half of a drug’s active substance to be eliminated from the bloodstream. Think of it like this: if you take a medication, the plasma half-life is the amount of time it takes for the concentration of the medicine in your blood to reduce by 50%. This is important because it helps doctors determine how often a medication should be taken to maintain its effectiveness without becoming too strong or weak.

A drug with a long half-life stays in the body longer, so doses can be spaced out more. Conversely, if a drug has a short half-life, it leaves the body quickly, and doses might need to be more frequent to keep up the effect.

Finasteride versus dutasteride

Finasteride specifically targets type II 5?-reductase and can reduce the level of DHT, a hormone linked to hair loss, in the scalp by about 41%. Dutasteride, which blocks type I and type II, can reduce scalp DHT by about 51% [11]. Other research has shown that these drugs can decrease the DHT levels in hair by about 64% for finasteride and 92% for dutasteride [12]. Therefore, for patients with androgenetic alopecia (AGA) or male pattern baldness who do not see improvement with finasteride, dutasteride might be a more practical option.

More evidence that dutasteride is more effective than finasteride at treating hair loss

Since finasteride targets only the type II 5-alpha reductase, while dutasteride blocks both type I and type II of this enzyme, we would expect it to be more effective. Studies including hair counts, scalp photos, and personal assessments by subjects have shown that dutasteride, taken at 0.5 mg per day, is more effective than finasteride at promoting hair growth and increasing the number and thickness of hair. Two meta-analyses [13,14], which are extensive collective studies, have proven this. To learn more about meta-analyses, read the section below.

However, one criticism of these studies is that they were only conducted over 24 weeks. Future studies that are larger and longer could explore this treatment further.

So, if you have tried finasteride 1mg tablets or the compounded finasteride 0.1% hair loss liquid or foam without much improvement, provided that you did not experience any severe side effects, it might be worthwhile considering dutasteride.

After completing a health questionnaire, you can purchase both the dutasteride 0.5mg capsules and the compounded dutasteride 0.1% minoxidil 5 and 10% hair loss liquid and foam from Medical Mojo.

Summary

In this blog, we explored the efficacy of dutasteride, a medication commonly used to treat hair loss and conditions like an enlarged prostate. We examined how dutasteride works by inhibiting DHT (dihydrotestosterone), a hormone linked to hair loss, and discussed studies that show its effectiveness compared to other treatments like finasteride.

At Medical Mojo, we aim to provide the information you need to make informed health decisions. If you found this article helpful or have any questions or suggestions for future topics, feel free to get in touch!

Losing your hair?

Try clinically proven hair loss treatments for men and women.

Learn more

References:

1. Lolli F, Pallotti F, Rossi A, Fortuna MC, Caro G, Lenzi A, et al. Androgenetic alopecia: a review. Endocrine. 2017;57(1):9–17.
2. Bertoli MJ, Sadoughifar R, Schwartz RA, Lotti TM, Janniger CK. Female pattern hair loss: a comprehensive review. Dermatol Ther. 2020;33(6):e14055.
3. Ceruti JM, Leirós GJ, Balañá ME. Androgens and androgen receptor action in skin and hair follicles. Mol Cell Endocrinol. 2018;465:122–33.
4. Randall VA. Androgens and hair growth. Dermatol Ther. 2008;21(5):314–28.
5. Piérard-Franchimont C, Piérard GE. Teloptosis, a turning point in hair shedding biorhythms. Dermatology. 2001;203(2):115–7.
6. Asada Y, Sonoda T, Ojiro M, Kurata S, Sato T, Ezaki T, et al. 5 alpha-reductase type 2 is constitutively expressed in the dermal papilla and connective tissue sheath of the hair follicle in vivo but not during culture in vitro. J Clin Endocrinol Metab. 2001;86(6):2875–80.
7. Sánchez P, Serrano-Falcón C, Torres JM, Serrano S, Ortega E. 5?-Reductase isozymes and aromatase mRNA levels in plucked hair from young women with female pattern hair loss. Arch Dermatol Res. 2018;310(1):77–83.
8. U.S. Food and Drug Administration. Avodart [Internet]. [cited 2024 March 1]. Available from: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=BasicSearch.process
9. Ministry of Food and Drug Safety [Internet]. [cited 2024 March 1]. Available from: https://nedrug.mfds.go.kr/pbp/CCBBB01/getItemDetailCache?cacheSeq=200409982aupdateTs2024-02-10%2019:57:48.0b
10. Pharmaceuticals and Medical Devices Agency [Internet]. [cited 2024 March 1]. Available from:https://www.pmda.go.jp/PmdaSearch/iyakuDetail/ResultDataSetPDF/480235_249900AM1031_1_06
11. Olsen EA, Hordinsky M, Whiting D, Stough D, Hobbs S, Ellis ML, et al. The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride. J Am Acad Dermatol. 2006;55(6):1014–23.
12. Google ScholarCrossref PubMed
13. Zhou Z, Song S, Gao Z, Wu J, Ma J, Cui Y. The efficacy and safety of dutasteride compared with finasteride in treating men with androgenetic alopecia: a systematic review and meta-analysis. Clin Interv Aging. 2019;14:399–406.
14. Gupta AK, Venkataraman M, Talukder M, Bamimore MA. Relative efficacy of minoxidil and the 5-? reductase inhibitors in androgenetic alopecia treatment of male patients: a network meta-analysis. JAMA Dermatol. 2022;158(3):266–74.
15. Harcha, W.G., Martínez, J.B., Tsai, T.F., Katsuoka, K., Kawashima, M., Tsuboi, R., Barnes, A., Ferron-Brady, G. and Chetty, D., 2014. A randomized, active-and placebo-controlled study of the efficacy and safety of different doses of dutasteride versus placebo and finasteride in the treatment of male subjects with androgenetic alopecia. Journal of the American Academy of Dermatology, 70(3), pp.489-498.
16. Jung, J.Y., Yeon, J.H., Choi, J.W., Kwon, S.H., Kim, B.J., Youn, S.W., Park, K.C. and Huh, C.H., 2014. Effect of dutasteride 0.5 mg/d in men with androgenetic alopecia recalcitrant to finasteride. International Journal of Dermatology, 53(11), pp.1351-1357.