I want to purchase a bleach..

pigmented areas like the elbows, knees.. how safe is it by the way, i just use natural like lemon extract but it doesn't seem to work..how should i go about doing it...

if it wasn't safe, it wouldn't be sold. check for skin irritation in a little spot before you apply it all over. if you break out, it means your skin is sensitive.

You might want to go to a beauty supply store, there they can show you which bleaching cream would be the best for you,