Zinc as an Ambivalent but Potent Modulator of Murine Hair Growth In Vivo: Preliminary Observations

In the 2005 study, researchers found that high-dose oral zinc significantly influenced hair growth in mice, with both inhibitory and stimulatory effects. Zinc delayed the anagen phase and prolonged the catagen phase of hair growth, suggesting an inhibitory role. However, zinc also accelerated the regrowth of hair following chemotherapy-induced damage, indicating a potential for promoting hair follicle recovery. The effects of zinc were found to be dependent on the timing and duration of administration, with prolonged use leading to retarded hair regrowth. The study concluded that zinc is a potent but ambivalent modulator of hair growth, and its role in potentially mitigating chemotherapy-induced hair loss or stimulating hair regrowth in humans requires further investigation. The number of mice used in the study varied, with 3 to 5 for histomorphometry and up to 34 for pooled macroscopical findings.