Here’s what consumers have asked with answers from Acne Free staff and previous consumers.
I'm not sure about studies but they do seem to work. My daughter has had very good results from these products.
My daughter has used this off and on for years and it usually takes about a week for her start seeing her skin getting clearer.
They sell full kits and I would suggest picking the one that best suited for your skin. They offer the standard oil-free system, a maxiumum strenght and sensitive version.