Topical Minoxidil and Tretinoin Combined with an Oral Vitamin D Analog as a Treatment for Woolly Hair

In 2016, a study was conducted on two girls aged 4 and 6 with woolly hair, a disorder causing structural defects in hair shafts. The girls had tightly-curled, fine, short, brownish hair with diffuse hair loss since birth. The researchers treated the girls with daily topical minoxidil (3% gel) and tretinoin (0.025%) combined with an oral vitamin D analog (alfacalcidol 0.25 µcg/day). After 5 months of treatment, hair thickness and density improved. Before treatment, the girls' hair thickness was 0.047 mm and 0.037 mm, which increased to 0.050 mm and 0.047 mm, respectively. Hair density also increased from 90/cm² and 110/cm² to 110/cm² and 140/cm², respectively. The study concluded that these therapeutic options could have potential for the conservative management of woolly hair, but further investigation is needed.