Here's my experience with this regime: I never ever used moisturizer because I have really acne prone skin (severe acne in my teens and then again mid twenties) Then in my mid twenties during a year of really bad cystic acne on my jaw especially, a cosmetologist convinced me to start level 1. Although I was really nervous of moisturizers (every cream I had EVER tried led to a massive breakout), I was desperate and thought what the heck, it can't get worse. The first few weeks I had quite a reaction to the vitamin A, peeling badly in all the areas I had acne. I didn't care, I was willing to push through because it was clearly acting on my spots. When the reaction stopped, my skin had reduced breakouts so I continued. I stepped up to level 2 and then 3 without drama, and started combining them with Environ acne peels. My skin has NEVER looked so good. My scars slowly reduced and I was so happy. After I turned 30 my skin started to feel a bit dry on level 3. So I stepped up to level 4. I definitely had a wee acne reaction on my problem areas (chin, nose) but the rest of my skin feels amazing. It spreads really well and absorbs quickly. I cannot stress how acne prone my skin is, and to find a cream that targets my aging without creating spots is honestly an HG product for me. I highly recommend this range, but follow it according to recommendations.