Minoxidil

Minoxidil is a synthetically produced active ingredient that was originally developed as an antihypertensive for the treatment of high blood pressure. It was introduced clinically in the 1970s because, as a powerful vasodilating agent, it could help with difficult-to-treat hypertension. Soon, however, an unexpected side effect became apparent: patients developed increased body and scalp hair growth. This effect led to Minoxidil being known today primarily as a topically applied remedy for hair loss (alopecia).

Minoxidil is used worldwide in the form of solutions or foams for external application. Through the dilation of blood vessels and an improvement in nutrient supply in the area of the hair follicles, it can promote hair growth and slow down hair loss.

What health benefits does Minoxidil offer?

  • Blood pressure reduction: As a powerful vasodilator, Minoxidil can be effective in difficult-to-treat hypertension (1,2).
  • Promotion of hair growth: The best-known application concerns the treatment of hereditary hair loss (androgenetic alopecia) in men and women (3,4).
  • Stabilization of hair follicles: Studies show that Minoxidil can prolong the growth phase (anagen phase) of the hair (3,4).

How does Minoxidil work in the body?

The mode of action of Minoxidil has not yet been fully clarified, but several mechanisms are considered likely:

  • Vasodilation: By activating potassium channels in the vascular muscle cells, Minoxidil widens the blood vessels, which leads to better blood flow (1,2).
  • Stimulation of the hair follicles: Presumably, the improved microcirculation of the scalp ensures that hair follicles receive more oxygen and nutrients (3,4).
  • Hair cycle modification: Minoxidil prolongs the growth phase (anagen phase) of the hair and shortens the resting phase (telogen phase) (3,4).

Are there any risks or side effects?

  • With external use: Skin irritation, itching, redness, or flaking are possible. In rare cases, increased unwanted hair growth occurs outside the treated areas.
  • With internal use: As a blood pressure-lowering agent, Minoxidil can lead to severe hypotension, fluid retention, and rapid heartbeat. It is therefore used in this form only in exceptional cases and under strict medical supervision.
  • Long-term use: To maintain the effect in hair loss, the treatment must be continued permanently, as the effect is lost again after discontinuation.

Conclusion

Minoxidil is a versatile active ingredient that evolved from a blood pressure-lowering drug into a globally established remedy for hair loss. While its blood pressure-lowering effect is only rarely used today, it is widely used as a topical preparation for the treatment of androgenetic alopecia. Despite its successes, one thing holds true: Minoxidil is not a cure but can merely slow down hair loss or partially reverse it – continuous use is crucial.

Sources:

  1. Knutsen, R. H., Beeman, S. C., Broekelmann, T. J., Liu, D., Tsang, K. M., Kovacs, A., Ye, L., Danback, J. R., Watson, A., Wardlaw, A., Wagenseil, J. E., Garbow, J. R., Shoykhet, M., & Kozel, B. A. (2018). Minoxidil improves vascular compliance, restores cerebral blood flow, and alters extracellular matrix gene expression in a model of chronic vascular stiffness. American Journal of Physiology-Heart and Circulatory Physiology, 315(1), H18–H32. https://doi.org/10.1152/ajpheart.00665.2017
  2. Bursztyn, M., & Ben-Dov, I. Z. (2025). Contemporary use of an old drug: Minoxidil for resistant hypertension. Hypertension, 82(4). https://doi.org/10.1161/HYPERTENSIONAHA.124.23976
  3. Gupta, A. K., Talukder, M., Venkataraman, M., & Bamimore, M. A. (2022). Minoxidil: a comprehensive review. The Journal of dermatological treatment, 33(4), 1896–1906. https://doi.org/10.1080/09546634.2021.1945527
  4. Olsen, E. A., Dunlap, F. E., 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. https://doi.org/10.1067/mjd.2002.124088