This is quite a weird question! However, it seems permissible as human hair and the feathers of birds are TAHIR and they don’t require slaughtering like meat. Therefore, it seems permissible to use if proven to be medically safe!

I would like to know what is the ruling of using human hair,duck feathers in bread products.the ingredient called L-cystein.in USA mostly all of the french and Italian bread made with this ingredient.