My hair is not curly -- but more wavy with tons of frizz. I don't think it makes it less wavy - just eliminates the frizz.
There was someone here -- I believe the thread starter -- that posted pics somewhere. She was able to wear her hair naturally -- sans blowdrying -- and her hair had nice soft curls and waves with no frizz.
The effects slowly wear off, so re-growth is not noticeable.