[lipshock]

My doctor told me this when I asked about her about dark underarms as well:

Avoid using deodorants with the active ingredient: Aluminum Zirconium Tetrachlorohydrex GLY. Whattamouthfull! Basically it's an anti-perspirant and will be found in deodorants that fight against perspiration.

Mitchum makes some good deodorants without that ingredient and I have yet to see sweaty pits on me (ew, gross!). I don't use them though. I actually use this all-natural Crystal Rock deodorant, that you wet the top with water and rub under your arms. I got it from Trader Joe's and Whole Foods.

I have yet (crossing fingers) to suffer from sweaty pits and dark underarm areas!

Hope this helps some!