The Revitalizing Toner is best used after cleansing the face. The toner contains (but is not limited to): 
Vitamin C
Tea Tree Oil
Salicylic acid
In regards to helping treat acne the ingredients listed either help with curing the hyperpigmentation from acne scarring, or the leveling out of the skin after ice pick/rolling/boxcar scars occur. Product also works to take out the impurities in the skin to prevent further acne.