Retinol—a word used often, but not always understood. You might use your nightly retinol cream because the label said it “diminishes wrinkles” or “firms skin,” but do you know why or how? What about Retin-A, which only your derm can prescribe? Is there really a difference between the two? We decided to get to the bottom of the debate and asked dermatologist Dr. Vermén M. Verallo-Rowell all our pressing retinol-related questions. Turns out, there’s a lot about this compound you might not know.