Doctors are warning users of hair growth treatment minoxidil after a 28-year-old woman experienced unexpected hair growth on her face, arms, and legs.
The woman, who suffers from alopecia—a condition affecting roughly 7 million Americans that causes hair loss—had been using a five percent minoxidil spray twice daily to treat her bald spots.
How Minoxidil Can Lead to Systemic Effects
Minoxidil, sold in the U.S. under the brand name Rogaine, is applied to the scalp to stimulate hair growth. While generally safe, it can be absorbed into the bloodstream if misused. Patients typically apply the foam or spray and allow it to absorb.
In this case, the woman wore a wig during the day and a tight cap at night. Doctors say this “constant occlusion” of the scalp likely increased systemic absorption of the medication, causing hair growth in unintended areas.
The FDA-approved safe dosage is one milliliter, or six sprays, twice daily. While minor side effects like scalp irritation, changes in hair texture, or color are common, excessive hair growth—known medically as hypertrichosis—can occur when the drug enters the bloodstream at higher levels.
Patient Background and Treatment History
The patient, from France, had a large bald spot on the top of her head and mild deficiencies in vitamin D and zinc, which can affect hair follicle health. Alongside minoxidil, she underwent three monthly sessions of LED therapy and platelet-rich plasma (PRP) injections, which use plasma rich in growth factors to stimulate scalp hair growth.
After two months of minoxidil use, the woman reported significant hair growth on her face, arms, and legs. Doctors linked this to wearing the wig and tight cap, which kept her scalp constricted and blocked hair follicles, increasing systemic drug absorption.
Medical Advice and Outcome
In a medical journal report, doctors emphasized:”Minoxidil is an effective treatment but can occasionally lead to hypertrichosis, especially when applied in high concentrations or over large areas of the body. This case illustrates the critical need for precise patient instruction on the correct application of topical therapies to prevent adverse systemic effects.”
The woman discontinued minoxidil and underwent laser hair removal to address the unwanted facial hair. She continued her other hair restoration treatments safely.
With around 40 million Americans using minoxidil for hair loss, doctors urge caution and adherence to dosage instructions, especially when combining the treatment with wigs or tight head coverings that may increase absorption.
