Hope for bald men? Perhaps. A study suggests that plucking out one's hair could actually trigger the growth of even more. But before anyone starts tearing at his scalp, know that the plucking process has to be done in a specific way—and has thus far only been tested on mice, the Guardian reports. Still, the results, published in the journal Cell, are promising. Scientists say they involve the way hair follicles communicate with each other. The removal of the hair, done right, causes a "distress" signal in the body that leads to an immune response; the body is essentially told to start growing more hair, the Guardian reports. The process worked when mouse hairs were individually removed from a dense patch, a circular area of between 3 and 5 millimeters.
In such cases, when 200 hairs were plucked, up to 1,300 grew back—with some even sprouting up outside the plucked area. But when 200 hairs were removed across an area whose diameter was more than 6 millimeters, none returned. The researchers believe that's because the follicle signaling doesn't work across such a wide space. The BBC adds that more isn't more, in this case: The researchers tested pulling out every hair from a specified area, but found that while those hairs grew back, there was no additional growth. The researchers caution the experiments need to be carried out on bald men, and the Guardian notes that even if the approach does work on humans, it would only help balding men who still had the required amount of hair density. The findings are among the first to point to such group signaling, or quorum sensing, in animal cells, as opposed to bacteria, Scientific American reports. (It's not the only lead in the fight against baldness.)