So, I did what any beauty editor would do: I polled some experts. And, it turns out, even they aren't 100% aligned on the topic. "Many people ask for specifics on the best time to use a physical exfoliant, but it really is dependent on the individual's habits and lifestyle," says dermatologist Harold Lancer, MD. "If someone wears makeup on a daily basis, exfoliating at night would help to lift any remaining makeup particles from the skin and ensure that your products are penetrating properly," he adds. But Dr. Lancer goes on to say that if your face is dull in the morning, or if you have oily skin, exfoliating in the a.m. may be best.