One option for treating hair loss due to androgenetic alopecia in men is the administration of oral 5-alpha-reductase inhibitors or dihydrotestosterone or DHT blockers. Finasteride is the most common DHT blocker prescribed to men suffering from male pattern hair loss but dutasteride has also been regarded as another effective medication. This article provides a side-by-side comparison between finasteride and dutasteride.
A Comparison of the Effectiveness of Finasteride and Dutasteride in Treating Hair Loss and Promoting Hair Growth
Topical minoxidil is the most common treatment for individuals with androgenetic alopecia. However, despite its proven effectiveness, there are cases in which treatment using DHT blockers are deemed more suitable because of their more potent effects in arresting hair loss and maximizing hair regrowth. Finasteride or dutasteride can be taken in replacement of minoxidil or as a complementary treatment option. The following are the main comparison points to evaluate which between finasteride and dutasteride is more effective:
Mechanism of Action
Remember that both finasteride and dutasteride are DHT blockers. Their general mechanisms of action are the same. A DHT blocker specifically inhibits the enzyme called 5-alpha-reductase. This enzyme is responsible for the production of dihydrotestosterone or DHT.
It is important to note that DHT is an androgen or sex hormone derived from testosterone. It is found in different tissues of the body and is present at higher levels in men. This hormone is also the main androgen in the skin and hair follicles.
Studies have noted the adverse health effects of excess DHT levels. These include benign prostatic hyperplasia or BPH and androgenetic alopecia or male pattern baldness. Both finasteride and dutasteride were originally formulated to treat BHP.
Nevertheless, because both medications inhibit the enzyme responsible for converting testosterone into DHT, and because high levels of DHT have been linked to androgenetic alopecia in men, they have been prescribed for treating hair loss.
Finasteride specifically inhibits the type II and type III isoforms of 5-alpha-reductase while dutasteride inhibits the type I and type II isoforms. Take note that type I and type II 5-alpha-reductase are abundant in the skin and hair follicles.
Availability and Administration
Both medications are available in most pharmacies in different parts of the world. The Food and Drug Administration of the United States has approved finasteride for the treatment of BPH and androgenetic alopecia. The same agency has approved dutasteride for BPH treatment but it remains an off-label medication for treating hair loss.
Dutasteride is also not an approved medication for treating male pattern hair loss in the European Union, unlike finasteride. Both the U.S. FDA and the European Medicines Agency have noted that there is a need for more studies that would investigate and determine the effectiveness and long-term safety of dutasteride when used as a hair loss medication.
The Pharmaceuticals and Medical Devices Agency of Japan and the Ministry of Food and Drug Safety of South Korea have approved both finasteride and dutasteride for BPH treatment and male pattern hair loss treatment. Nevertheless, considering the different regulations around the world, finasteride is more accessible.
Finasteride is a once-a-day medication taken at an ideal dose of 1 milligram while the existing consensus regarding the administration and dosing of dutasteride suggests a 0.50-milligram dosage taken once a day. Both medications are administered and taken via the oral route. They can also be taken without medical supervision.
There is an abundance of studies that have investigated, explained, and documented the effectiveness of finasteride and dutasteride in treating hair loss in men due to androgenetic alopecia or male pattern hair loss.
A comparative study by E. Arca et al. involving men with androgenetic alopecia or male pattern hair loss concluded that the clinical cure rates were 80 percent for the oral finasteride group and 52 percent for the topical minoxidil group.
Finasteride is more effective than topical minoxidil in terms of long-term effects on arresting hair loss due to androgenetic alopecia and in promoting ideal hair growth with better hair volume. Dutasteride appears to be the more effective treatment option.
Researchers G. S. Choi et al. concluded that dutasteride showed greater effectiveness in improving the anterior hairline and the density of hair on the frontal and vertex areas of the scalp compared to finasteride. Both are still effective but the latter is more potent.
E. A. Olsen et al. compared the effects of dutasteride, finasteride, and placebo in 416 young men experiencing hair loss. They concluded that dutasteride is about 3 times more potent than finasteride at inhibiting type II 5-alpha-reductase.
Dutasteride is also 100 times more potent in inhibiting type I 5-alpha reductase. The Olsen et al. research also revealed that a 5-mg finasteride decreases serum DHT by about 70 percent while a 2.5-mg dutasteride can decrease DHT by more than 90 percent.
Safety and Known Side Effects
Both are generally safe based on current studies. However, between the two, finasteride has a better wealth of long-term and high-quality studies that have investigated and confirmed both its effectiveness and safety. The U.S. FDA and the E.U. EMA noted more studies are needed to ascertain the safety of dutasteride as a hair loss medication.
It is also important to underscore the fact that both can still produce several side effects. Several researchers have identified some of the most common adverse effects of taking DHT blockers. These include a decrease in sex drive, erectile dysfunction, and a decrease in the amount of semen. Some have reported cognitive problems.
There are reports that some individuals experience the aforementioned side effects in extreme cases. The U.S. FDA has added a black-box warning to 5-alpha-reductase inhibitors such as finasteride and dutasteride due to concerns about their potential to increase the risk of developing a high-grade form of prostate cancer.
Understanding Why Dutasteride is More Effective than Finasteride in Treating Hair and Promoting Hair Growth
The studies cited above highlight the importance of inhibiting 5-alpha-reductase to block the production of DHT from testosterone and arrest the progression of hair loss due to androgenetic alopecia. Remember that high levels of DHT lead to the shrinkage of hair follicles.
A wealth of studies has backed the effectiveness of finasteride and dutasteride in treating hair loss due to androgenetic alopecia and in promoting hair growth. These medications work as 5-alpha-reductase inhibitors that block the production of DHT.
However, between the two, some studies have noted that dutasteride is more effective than finasteride. This comes from the fact that it has a greater potency in inhibiting the type I and type II isoforms of 5-alpha-reductase.
It is still indispensable to note that finasteride remains the only 5-alpha-reductase inhibitor approved by the U.S. FDA and the E.U. EMA for treating hair loss in men due to androgenetic alopecia or male pattern hair loss.
Both medications also have the same limitations. DHT blockers are not a cure-all solution for different causes of hair loss. Specific types of hair loss such as alopecia areata, telogen effluvium, and scarring alopecia require different treatment approaches.
FURTHER READINGS AND REFERENCES
- 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
- Choi, G.-S., Sim, W.-Y., Kang, H., Huh, C. H., Lee, Y. W., Shantakumar, S., Ho, Y.-F., Oh, E.-J., Duh, M. S., Cheng, W. Y., Bobbili, P., Thompson-Leduc, P., and Ong, G. 2022. “Long-Term Effectiveness and Safety of Dutasteride versus Finasteride in Patients with Male Androgenic Alopecia in South Korea: A Multicentre Chart Review Study.” Annals of Dermatology. 34(5): 349. DOI: 5021/ad.22.027
- Olsen, E. A., Hordinsky, M., Whiting, D., Stough, D., Hobbs, S., Ellis, M. L., Wilson, T., and Rittmaster, R. S. 2006. “The Importance of Dual 5α-reductase Inhibition in the Treatment of Male Pattern Hair Loss: Results of a Randomized Placebo-Controlled Study of Dutasteride versus Finasteride. Journal of the American Academy of Dermatology. 55(6): 1014-1023. DOI: 1016/j.jaad.2006.05.007