Studies: How effective is topical minoxidil for hair loss? The effectiveness of topical minoxidil

Studies: How Effective is Topical Minoxidil for Hair Loss?

Androgenic alopecia is hair loss resulting from androgenic miniaturization of hair follicles. It is also known as male-pattern hair loss when it affects men or female-pattern hair loss when it affects women. Nonetheless, this condition can lead to psychological distress due to diminished body image satisfaction.

There are several treatment options aimed at managing androgenic alopecia. One of which is the topical application of minoxidil: an over-the-counter antihypertensive vasodilator medication used for slowing or stopping hair loss and promoting hair regrowth.

The effectiveness of topical minoxidil for treating hair loss

A comprehensive review of literatures authored by K. Franca et al. mentioned that the application of topical minoxidil is the most widely recommended treatment for androgenic alopecia. It is available in 2 and 5 percent solutions. However, the United States Food and Drug Authority only allows 2 percent solution for use in female patients.

There is a 30-year scientific consensus attesting to the effectiveness of topical minoxidil in stimulating hair growth. However, its mechanism of action remains unclear. According to a review by A. G. Messenger and J. Rundegren, previous animal studies revealed an effect centered on shortening telogen or the resting phase of hair follicles that in turn, cause premature entry into an anagen phase or growth phase. It can also prolong this growth phase and increase the size of follicle resulting in thicker hair. Researchers believe that these effects are similar in humans.

Messenger and Rundegren also mentioned several in vitro effects of topical minoxidil in monocultures of skin and hair follicles. These effects include stimulation of cell proliferation, inhibition of collagen synthesis, and stimulation of vascular endothelial growth factor and prostaglandin synthesis. Accordingly, these effects might be relevant to hair growth although direct correlations remain unknown.

Another common explanation of the effectiveness of topical minoxidil centers on its property of being an antihypertensive vasodilator. Hypothetically, because it widens blood vessels, it thereby allows more oxygen, blood, and nutrients to the hair follicle.

Several clinical trials involving human subjects have been conducted to probe further the effects of topical minoxidil. For example, a dated 1990 study by A. Goren et al. revealed that 40 percent of observed patients had positive response to 5 percent of topical minoxidil after three to six months of use. Another 2002 study by Olsen et al. revealed that men who used 5 percent topic minoxidil had an earlier treatment response than those who use 2 percent minoxidil solution.

Limitations to the effectiveness of topical minoxidil

But the effectiveness of topical minoxidil in inducing hair growth and treating androgenic alopecia only lasts during the period of continued application. In other words, this medication must be used indefinitely to continuously support existing hair follicles and maintenance of continued hair growth. A study by V. H. Price, E. Menefee, and P. C. Strauss concluded that cessation of topical minoxidil treatment resulted in reduction of hair weight and number count after 28 weeks, with levels similar to placebo group.

Olsen et al. also made an interesting study that followed patients who underwent topical minoxidil treatment within a period of five years. The study revealed that hair regrowth peaked at one year before slowing down over subsequent years. Note that during the mid fourth and fifth years, hair regrowth remained evident albeit at a slowed phase. The study concluded that topical minoxidil is effective in maintaining non-vellus or terminal hair in men with androgenic alopecia.

A literature review by T. Scow, R. S. Nolte, and A. F. Shaughnessy revealed another setback. Their review revealed that the effectiveness of topical minoxidil in treating hair loss has been largely demonstrated in men aged 18 to 41. In addition, this medication is mostly effective on men who have experienced hair loss for less than five years. Further studies are needed to assess its effects on middle-aged to late-aged men and women.

Takeaway: How effective is topical minoxidil for hair loss?

In conclusion, there is a sizeable body of literatures detailing the effectiveness of topical minoxidil as hair loss medication and in promoting hair regrowth. Despite these studies however, its mechanism of action remains unclear. Despite this, its mechanism of action remains unclear. Animal models and human clinical trials have generally revealed that topical minoxidil is effective for treating or more appropriately, managing androgenic alopecia.


  • Franca, K., Rodrigues, T. S., Ledon, J., Savas, J., & Chacon, A. 2013. Comprehensive overview and treatment update on hair loss. Journal of Cosmetics, Dermatological Sciences and Application. 3(3A): 1-8. DOI: 10.4236/jcdsa.2013.33A1001
  • Goren, A., Shapiro, J., Roberts, J., McCoy, J., Desai, N., Zarrab, Z., Pietrzak, A., & Lotti, T. 2014. Clinical utility and validity of minoxidil response testing in androgenic alopecia. Dermatologic Therapy. 28(1): 13-16. DOI: 10.1111/dth.12164
  • Messenger, A. G. & Rundegren, J. 2004. Minoxidil: Mechanisms of action on hair growth. British Journal of Dermatology. 150(2): 186-194. DOI: 10.1111/j.1365-2133.2004.05785.x
  • Olsen, E. A. F. E. Dunlap, Funicella, T., Koperski, J. A., Swinehart, J. M., Tschen, E. H., & Trancik, R. J. 2002. A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men. Journal of the American Academy of Dermatology. 47(3): 377-385. DOI: 10.1067/mjd.2002.124088
  • Olsen, E. A., Weiner, M. S., Amara, I. A., & DeLong, E. R. 1990. Five-year follow-up of men with androgenetic alopecia treated with topical minoxidil. Journal of the American Academy of Dermatology. 22(4): 643-646. DOI: 10.1016/0190-9622(90)70089-Z
  • Price, V. H., Menefee, E., & Strauss, P. C. 1999. Changes in hair weight and hair count in men with androgenetic alopecia, after application of 5% and 2% topical minoxidil, placebo, or no treatment. Journal of the American Academy of Dermatology. 41(5): 717-721. DOI: 10.1016/S0190-9622(99)70006-X
  • Scow, D. T., Nolte, R. S., Shaughnessy, A. F. 1999. Medical treatments for balding in men. American Family Physician. 59(8): 2189-2194. Available online