Here's Why Stress Could Make Your Hair Fall Out, According to New Mouse Study - ScienceAlert

"In this work, we found that stress does actually delay stem-cell activation and fundamentally changes how frequently hair follicle stem cells regenerate tissues.".

The hair follicle controls hair growth in mammals, and the stem cells found within naturally cycle between periods of growth and periods of rest.

Giving mice extra corticosterone had the same effect on the hair stem cells as actually stressing the animals out with relatively harmless techniques such as cage tilting and flashing lights.

That suggests even normal levels of corticosterone in mice have an important regulating effect when it comes to hair growth, and additional stress could well be the reason why hair follicles and their stem cells become dormant for longer.

Further tests showed that adding GAS6 on top of both normal and elevated corticosterone levels in the mice activated the hair follicle stem cells and promoted hair growth via the protein AXL that passes the message on.