The use of a phototherapy laser to stimulate hair follicle activity is not new. Interest in another - the team of Professor Keon Jae Lee from the Korea Institute of Science and Advanced Technology was among the first in the world to develop applied technology based on these principles. It is a low-power analogue of a laser that significantly accelerates hair growth in mammals.
Instead of a powerful laser, the professor's team used weak micro light-emitting diodes (μLED). They placed 900 of these emitters on a postage stamp-sized panel flexible enough to withstand 10, 000 twisting cycles. The power of the system is less than one thousandth of that of a medical phototherapy laser, it practically does not heat the skin during irradiation and has no side effects.
In experiments, specially shaved mice were irradiated with red light once a day for 15 minutes for 20 days. In parallel, the same group was taking the proven hair growth drug minoxidil, plus there was a control group with which they did nothing. Irradiation showed an excellent effect, the hair grew much faster than in other groups, over a large area and was on average longer than with natural growth.
So far, the technology is experimental and has not yet been applied to humans, but it is not difficult to imagine a cap with LEDs, which helps to regain lost hair in a few sessions. Plus, such therapy would help restore hair after chemotherapy or help those who were born beardless by nature.