I had acne for many years, but then i decided to change my diet for health and longevity. So I cut out ALL bad food and started eating around 3-4 lbs of vegetables a day (around 10 different ones), lots of berries and low sugar fruits, wholegrains like oats, nuts, fish oil and fish like salmon and I practice something called Calorie Restriction. I supplemented with all vitamins, minerals and essential fatty aciRAB too. People started commenting on how good my skin looked, just after a few months of changing my lifestyle.
Only if I knew when I was younger about diet and acne, I might have prevented some of the red marks left over. But they continue to fade over time.
Oh and getting rid of anxiety or stress is sooo important too.