The repairing anti-acne serum is best used after toning and cleansing the face. The serum contains (but is not limited to): 
Vitamin C
Tea Tree Oil
Hyaluronic acid
In regaards ro helping treat acne the ingredients listed either help with curing the hyperpigmentation from acne scarring, or the eveing back of the skin after ice pick/rolling/boxcar scars occur, aswell as to overall take out the impurities in the skin to prevent further acne.