What is Minoxidil?
Minoxidil is an FDA-approved treatment available over the counter and by prescription. The prescription-strength minoxidil is 5% or greater, while the over-the-counter treatment is 2%. Minoxidil increases the anagen phase (hair growth) and shortens the telogen phase (hair loss). It also enlarges maturing hair follicles. 

Minoxidil also enlarges maturing hair follicles which places them back in action sooner. It is thought that Minoxidil does this by increasing blood flow to the skin and hair follicles and increasing prostaglandin (hair growth factors) levels.1 

Why is minoxidil part of my treatment plan?
Your genetic profile indicates efficacy with the use of minoxidil. Minoxidil must be activated in the body by a class of enzymes called sulfotransferases. Specific genetic changes make it so minoxidil is not activated by the body and will not be effective. Your genetic profile has enough sulfotransferase activity for minoxidil to be effective, but it may require higher doses.

Is topical minoxidil effective for alopecia?
Clinical trials have shown that Minoxidil 5% is more effective than 2%. This is why some men do not see improvement with treatment with over-the-counter strength minoxidil products. 

Treatment with topical minoxidil in clinical trials is associated with increased hair counts, patient ratings of scalp coverage and treatment benefit, and researcher ratings of scalp coverage. Treatment is also associated with an improvement in psychological perceptions of hair loss as well.2,3 

Are there adverse effects when using topical minoxidil?
Topical minoxidil is well tolerated, and adverse effects are infrequent. Topical therapy reduces the risk of systemic side effects because only a tiny portion of the dose is absorbed from the skin to reach the systemic circulation. Dermatitis, itching, irritation, and excessive facial hair growth in men have been reported. Minoxidil was initially used as a blood pressure medication; however, topical therapy is not associated with changes in blood pressure, pulse, or body weight.4 Some people experience an initial increase in hair shedding when starting minoxidil therapy.

Low-dose oral minoxidil carries the potential for serious adverse effects. It has a black box warning for the potential to cause severe pericardial effusions, increased heart rate, and worsen preexisting ischemic cardiac disease. Other adverse effects of oral minoxidil include low blood pressure, fluid retention, hair growth on different parts of the body, headache, insomnia, lightheadedness, and swelling around the eyes..5      

Why do I need to keep taking minoxidil for hair loss?
Minoxidil should be used once or twice a day as prescribed by your physician. Continuous use for four months is recommended before evaluating treatment response. Hair shedding may occur at the initiation of treatment as hair follicles are being stimulated to reenter the growth phase, but this frequently subsides within two months. Hair growth usually occurs within four to eight months and stabilizes over 12 to 18 months. Hair loss will occur over several months if treatment is stopped because of the nature of the hair growth cycle. Minoxidil is not a cure for hair loss; it is a treatment.

Medication Summary: Minoxidil

1) Messenger AG, Rundegren J. Minoxidil: mechanisms of action on hair growth. Br J Dermatol. 2004;150(2):186-194. doi:10.1111/j.1365-2133.2004.05785.x
2) Olsen EA, Dunlap FE, Funicella T, et al. A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men. J Am Acad Dermatol. 2002;47(3):377-385. doi:10.1067/mjd.2002.124088
3) Olsen EA, Whiting D, Bergfeld W, et al. A multicenter, randomized, placebo-controlled, double-blind clinical trial of a novel formulation of 5% minoxidil topical foam versus placebo in the treatment of androgenetic alopecia in men. J Am Acad Dermatol. 2007;57(5):767-774. doi:10.1016/j.jaad.2007.04.012
4) Rogaine extra strength for men (5 percent minoxidil topical solution): for nonprescription use. Summary volume, Pharmacia & Upjohn, Kalamazoo, MI 1997.
5) Vañó-Galván S, Pirmez R, Hermosa-Gelbard A, et al. Safety of low-dose oral minoxidil for hair loss: A multicenter study of 1404 patients. J Am Acad Dermatol. 2021;84(6):1644-1651. doi:10.1016/j.jaad.2021.02.054