My cat developed feline acne causing blackheads to form around his lips. I was advised by my veterinarian to use a drugstore acne product twice a day until it cleared up. A few months passed and the acne persisted, and my cat absolutely hated the application process and the taste of the product when he licked his lips. Then, two days before I left on a two-week vacation, I decided to try some of my Malibu C Serum on the affected area. When I returned from vacation, it had completely disappeared! I wish now that I had used it from the start, and if the acne returns, I wouldn't hesitate to use my serum again. Best of all, I can feel confident that my fur baby isn't ingesting anything harmful!