TLDR Some people using minoxidil for hair loss developed an allergic skin reaction, often related to an ingredient that helps minoxidil work better.
In a study from 32 years ago, 8 patients (1 male and 7 females, aged 24 to 41 years) who had been using minoxidil solution for androgenetic alopecia developed allergic contact dermatitis. Patch testing revealed that 7 of the patients were allergic to minoxidil alone, while one had a simultaneous allergy to both minoxidil and propylene glycol. The study emphasized the importance of the vehicle in patch testing for minoxidil, as all patients reacted to the topical minoxidil solution used and to minoxidil 2% in propylene glycol and water. However, tests with minoxidil in petroleum or ethanol were negative in some patients. The study concluded that propylene glycol, which enhances skin penetration of substances including minoxidil, is necessary for both the hair growth effects of minoxidil and to elicit contact sensitivity.
23 citations,
April 1991 in “Journal of The American Academy of Dermatology” Minoxidil solution can cause skin irritation and allergies in some users.
13 citations,
January 1988 in “Contact Dermatitis” Some patients using Minoxidil for baldness developed allergic skin reactions.
14 citations,
July 1987 in “Contact Dermatitis” A small percentage of minoxidil users may develop an allergic skin reaction.
14 citations,
July 1987 in “Contact Dermatitis” Minoxidil can cause allergic skin reactions in some users.
29 citations,
August 1985 in “Contact Dermatitis” Minoxidil can cause allergic reactions like burning, itching, and red bumps.
38 citations,
June 2005 in “Contact Dermatitis” Patient had scalp allergy from minoxidil; test helped identify cause and suggest alternative treatments.
212 citations,
September 2008 in “Journal of The American Academy of Dermatology” Minoxidil and finasteride treat hair loss in men, while minoxidil treats hair loss in women.
September 2010 in “Reactions Weekly” A woman was allergic to 5% minoxidil, with stronger reactions to higher concentrations.
January 2023 in “International Journal of Trichology” Alcohol-free minoxidil is better for treating hair loss in Indian men.
198 citations,
October 2011 in “Journal der Deutschen Dermatologischen Gesellschaft” Use minoxidil for hair loss; finasteride and dutasteride for men, dutasteride for women.
