How can I make my arm pit hair finer so I don't have to shave as often?

I have to shave like every morning and its a drag. I end up with five o'clock shadow of the pits and I hate it. I have fine blonde hair on my head but my arm pit hair is like thick and black, ewww! Is there a product I can use to make it so I don't have to shave as often? Thanks!!