My girlfriend has a lot of testostorone and is developing a bit of a mustache, which she has started to bleach. Me, being a naturalist, don’t think that bleach is a good idea. Are the health risks that she should know about? Is bleaching facial hair bad for you? Is there a better way for her to deal with her problem?
Depends on what she’s using to bleach it. Peroxide is safe when used correctly. I think she should consult someone with the proper training. Beauticians do receive training on this, and (in most states, at least) have to pass state boards on the safe and proper use of chemicals on those parts of the anatomy that they deal with.
This sounds right. Most hair bleach is hydrogen peroxide and used properly there should be no issue with it. Grabbing a bottle of bleach used to clean your kitchen could be a different matter and I wouldn’t try that.
So, follow directions on a purpose made hair bleach and all should be fine.
My mom and I have been using Jole Creme Bleach on our faces for many many years combined, and we’ve never experienced ill effects.
Of course, as the directions say, try a little bit first. Follow directions.
And as a High Testosterone Sister…let me please beg you to to not try to be all “naturalist” and try to convince her to shave or pluck. In my experience…it makes the hair come in thicker and more frequently. That’s not an urban legend…that is based on experience. Sucks 
Although at a certain point some HTSs need to surrender to reality and either start shaving or invest in electrolysis. Because at that point all the bleach is doing is giving you a white moustache, as opposed to some other color, rather than diminishing the appearance of upper lip hair.
But the bleach they sell specifically for bleaching “unwanted facial hair” should be safe for long term use when used as directed.
Plucked hair grows back more slowly than shaven hair, because shaving only cuts it back to the surface of the skin, but the rate of growth is identical in either case. In both cases, the hair can appear darker–and it actually is at first–because exposed hair tends to become sun bleached over time, while new hair growth has not. New hair growth can also appear thicker, but that’s because that hairs tend to become worn and tapered through washing and other daily activities, whereas new growth emerges with the shaft at full thickness.