I chose Evivo for my newborn who had a short run of antibiotics at birth. I gave it to him first when he was just over 2 weeks old, and that evening his face lit up with acne. I gave it every other day for 3 treatments and the acne just got worse so I stopped administering it. I read that an imbalance in gut bacteria can influence acne, so after a week I got an infant probiotic from my local grocer with 5 strains (including the one found in Evivo), and that first evening the acne had improved. With each use it improved, and in about 4 days it was gone. I am now kicking use of for buying 2 expensive months worth that I am afraid to use.