Pyroxylin shortens the resting stage of the hair cycle in mice.

Despite strong interest in scalp and body hair and a large hair-care market, effective and practical approaches for inducing hair growth remain limited. Here, we show that pyroxylin treatment shortens the resting stage of the hair cycle and induces localized hair growth in mice. Application of pyroxylin to various skin regions induced injury followed by hair growth, which was also triggered by other adhesive materials. The hair growth was accompanied by hair cycle-related gene expression and gradually synchronized with the cycle of surrounding hair growth. Notably, this approach was effective even in middle-aged and aged mice. Although direct comparisons with established wound-healing models and physiological hair-cycle systems will be needed to further define the scope and limitations of this approach, our findings suggest that pyroxylin treatment provides a useful experimental platform for studying localized hair growth, and they warrant further investigation of its potential for topical hair-growth induction.