"The short answer is: while glutathione itself doesn’t directly cause gray hair, its role in managing oxidative stress, a significant contributor to hair pigment loss, means its effects are complex and potentially implicated in the speed at which graying occurs."
https://necolebitchie.com/can-glutathione-cause-gray-hair/
"Research shows that a primary cause of grey hair is the excess accumulation of hydrogen peroxide that literally bleaches the hair from the inside out. Glutathione helps to prevent grey hair by turning hydrogen peroxide into water."
"Low antioxidant status and enzymatic activity through the catalase and glutathione peroxidase enzymes have been measured and shown to be low in people with grey hair."
https://www.ambersnaturalnutrition.com/what-causes-grey-hair-how-to-prevent-grey-hair/
"Hydrogen peroxide turns your hair gray, but glutathione renders hydrogen peroxide harmless by converting it to water. When glutathione is lacking, you face all sorts of potential damage – not just to your hair, but especially to your brain."
"If extreme stress continues, your body works hard at eliminating the excess stress neurotransmitters as fast as it can. It works triple-time if need be – all the while producing way too much hydrogen peroxide. Glutathione tries to keep up, but it can’t – it’s not an easy compound to make, and eventually your body runs out of it. In the end, the excess hydrogen peroxide wins out and discolors your hair, turning it gray or, if the intense stress persists, eventually white.
Excess hydrogen peroxide can discolor and damage your hair!"
https://www.healthygoods.com/blogs/news/gray-hair-glutathione-stress