Cyclosporin A Stimulates Hair Growth in Nude Mice

In a study conducted in 1987, cyclosporin A (CyA) was administered to six-week-old nude mice at doses of 10 and 100 mg/kg body weight/day for 14 days, resulting in significant hair growth on the neck, back, and hip regions, with hair length 3 to 4 times longer than that of control mice given only olive oil. The effect was observed from day 7 of treatment and was consistent across both doses and genders. However, no hair growth occurred in the abdominal region, and hair length returned to control levels 14 days after treatment cessation. Microscopic examination showed no difference in the number of hair follicles between treated and control mice.