Effectiveness of Finasteride in Treating Hair Loss: Studies

Effectiveness of Finasteride in Treating Hair Loss: Studies

Finasteride is a medication prescribed to treat benign hyperplasia in men and hair loss due to androgenic alopecia. It has also been used to treat cases of excessive hair growth in women.

This medication is not recommended to treat hair loss or hair thinning in women but some providers prescribe it to post-menopausal women who are not responding to topical minoxidil and oral spironolactone.

Nevertheless, there is an established body of studies examining and explaining the effectiveness of finasteride in treating hair loss and promoting hair growth.

Understanding Why Finasteride is Effective in Treating Hair Loss and Promoting Hair Growth: Evidence and Explanation from Studies

Evidence According to Studies

There are different causes of hair loss or alopecia. It is also important to underscore the fact that there are different general types of hair loss. Treating this problem first requires understanding the causes and determining which hair loss type the condition falls under.

Finasteride is specifically used to treat hair loss due to androgenetic alopecia or pattern hair loss. Several studies have investigated and documented its effectiveness. Take note of the following notable findings and conclusion:

• J. Shapiro and K. D. Kaufman noted in their 2003 review that hair growth occurred in 48 percent of men who took finasteride for a year and in 66 percent of men in the second year while hair growth occurred in 7 percent of men who received a placebo.

• The same review also highlighted findings from different phase III studies. These include that a 1-milligram daily dose of this medication resulted in a 14 percent net increase in hair count after 1 year and a 16 percent in hair count after 2 years.

• It also concluded that 90 percent of treated men maintained hair integrity with no visible hair loss from the baseline or sustained visible scalp coverage over 5 years while 75 percent of men in the placebo group showed visible hair loss.

• Another 2014 review by S. Varothai and W. F. Bergfeld concluded that oral finasteride and topical minoxidil provided the best level of evidence for effectiveness and safety when it comes to treating androgenetic alopecia in males.

• Researchers E. Arca et al. conducted a randomized comparative study of oral finasteride and topical minoxidil to determine which one is more effective. It concluded that both drugs were effective in treating androgenetic alopecia in males.

• Furthermore, based on the same comparative study, the clinical cure rates were 80 percent for the oral finasteride group and 52 percent for the topical minoxidil group. It concluded that finasteride was more effective than minoxidil.

• A 2012 study by A. Rossi et al. also concluded that 68 percent of men who took finasteride had an improvement in hair loss compared to 38 percent of men who took saw palmetto. This showed that the former is more potent at a smaller dosage.

Main Scientific Explanations

The effectiveness of finasteride in treating hair loss and promoting hair growth has also been investigated and explained in several studies. The consensus is that this medication blocks the production of dihydrotestosterone or DHT.

It is specifically a selective 5-alpha-reductase inhibitor or a blocker of enzymes involved in steroid metabolism including the formation of DHT from testosterone. Inhibiting this enzyme means blocking the production of DHT. Take note of the following:

High levels of DHT have been associated with androgenetic alopecia. DHT is the main androgen or sex hormone in the skin and hair follicles. Excess levels of this hormone lead to the miniaturization of follicles, thinning of strands, and hair fall.

• Finasteride is effective in treating hair loss due to androgenetic alopecia because it blocks the formation of DHT from testosterone. It is specifically an antiandrogen or an androgen synthesis inhibitor and a specific DHT blocker.

• This medication is specifically a selective inhibitor of the type II and III isoforms of 5-alpha-reductase. These two isoforms are essential in the conversion of testosterone in selected tissues from the more potent dihydrotestosterone.

• Note that type II 5-alpha-reductase or 3-oxo-5α-steroid 4-dehydrogenase 2 enzyme is present in the outer root sheaths of hair follicles. It is also present in the epididymis, vas deferens, seminal vesicles, and the prostate.

• J. Shapiro and K. D. Kaufman, in their review of Phase III vertex hair loss studies, explained that taking 1 milligram of this medication per day resulted in a marked and persistent suppression of serum DHT levels.

Pros and Cons of Finasteride

The aforementioned studies demonstrate and explain the effectiveness of finasteride in treating hair loss and promoting hair growth. The following are its specific advantages:

• Proven Effective and Safe: There is an abundance of studies demonstrating the effectiveness of finasteride in treating hair loss. There is also a decent amount of studies confirming its general safety and contraindications.

• Alternative Treatment Option: Several studies have also noted that this medication is more effective than topical minoxidil in treating androgenetic alopecia. It is prescribed to individuals who have a poor response to minoxidil.

• Accessible and Convenient: It is also accessible via prescription from a physician such as a dermatologist. This medication is available in pill form at 1 milligram. It is taken once a day without the need for medical supervision.

• Long-Term Effectiveness: Another advantage of finasteride is its long-term benefits in halting hair loss and even promoting hair growth. Several studies have suggested that its effects can persist for up to 10 years or more.

It is still important to note that there are different causes of hair loss. There are also different types. Finasteride is not a full-spectrum solution. Below are its disadvantages:

• Limitation of Effectiveness: Most studies involved men with androgenetic alopecia. It might have a limited effect on women with androgenetic alopecia. It is also not effective in hair loss due to scarring alopecia, alopecia areata, and telogen effluvium.

• Notable Documented Side Effects: This medication is safe but some develop adverse effects including a decrease in sex drive, erectile dysfunction, and a decrease in the amount of seminal fluid. Some have reported cognitive problems.

• Availability of Other Options: Finasteride blocks about 70 percent of DHT while dutasteride blocks more than 90 percent. Dutasteride has been shown to be more effective in both halting hair loss and promoting hair growth.


  • Arca, E., Açıkgöz, G., Taştan, H. B., Köse, O., and Kurumlu, Z. 2004. “An Open, Randomized, Comparative Study of Oral Finasteride and 5% Topical Minoxidil in Male Androgenetic Alopecia.” Dermatology. 209(2): 117-125. DOI: 1159/000079595
  • Rossi, A., Mari, E., Scarnò, M., Garelli, V., Maxia, C., Scali, E., Iorio, A., and Carlesimo, M. 2012. “Comparative Effectiveness and Finasteride vs Serenoa Repens in Male Androgenetic Alopecia: A Two-Year Study.” International Journal of Immunopathology and Pharmacology. 25(4): 1167-1173. DOI: 1177/039463201202500435
  • Shapiro, J. and Kaufman, K. D. 2003. “Use of Finasteride in the Treatment of Men With Androgenetic Alopecia (Male Pattern Hair Loss).” Journal of Investigative Dermatology Symposium Proceedings. 8(1): 20-23. DOI: 1046/j.1523-1747.2003.12167.x
  • Varothai, S. and Bergfeld, W. F. 2014. “Androgenetic Alopecia: An Evidence-Based Treatment Update.” American Journal of Clinical Dermatology. 15(3): 217-230. DOI: 1007/s40257-014-0077-5
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