Imagine how awesome it would be to have a dermatologist for a parent—someone you could talk to or text, day or night, about all things skin. Well, it turns out, derms’ kids are no different than anyone else when on the receiving end of advice from their parents: “My daughter’s eyes kind of glazed over the first time I started telling her what to do about her acne; I had to remind her that people pay me for my opinion,” laughs Peterson Pierre, M.D., a dermatologist in Thousand Oaks, California who has a daughter, 20, and son, 18. “But once she got that the advice was coming from a dermatologist, not ‘dad,’ she started following it.”

To give you the best of both worlds—the expert, insider advice without the parental opinion or commentary baked-in—we asked four skin gurus-slash-guardians about the most important wisdom they’ve handed down to their teens and 20-somethings.