Are there chemicals that will permanently depigment human hair?

Are there chemicals that will permanently depigment human hair?

 

If there are, they would have to work internally... like food... since hair keeps growing and the new hair growth coming out of the follicle will retain the natural color.

 

Then, there is, of course, cortisol (from stress), which results in permanent graying and whiting (word?) of hair.

 

 

EDIT:

 

Turns out that a method of delivering cancer medicine, liposomes, can also be used to deliver the molecular precursor to melanin, dihydroxyl-5.6-indole, essentially changing the color of the hair... internally. Well, how about that?

 

More at the link:

http://science.howstuffworks.com/hair-coloring5.htm

Since hair is essentially a column of dead cells that originate from a stem cell in the hair follicle, it follows that changing the stem cell will change the hair. So, if you changed the stem cell so that it didn't produce pigment, then all the daughter cells -- the hair -- would also be without pigment.

 

The website wants to deliver melanin specifically to those hair follicle stem cells. That way, when the stem cell divides, the daughter cell will also have melanin. As long as there is a steady supply of melanin (apply the liposomes regularly), then the stem cell will always have melanin in the cytoplasm when it divides and makes the daughter cell.