The Beauty Brains is run by actual cosmetic scientists and formulators. They even have a book debunking all sorts of myths about cosmetics (It's Okay To Have Lead in Your Lipstick). Personal Care Truth was started by two formulators and has contributions from people that have worked in the industry (e.g., formulators, those who know the science behind cosmetics). Robyn from Brightest Bulb in the Box has an interest in cosmetic science and has written many an article refuting various beauty myths, and I don't think she'd write everything she has done if she hasn't done her research. I'd rather believe them than those who probably don't know anything about cosmetic science and don't have the scientific evidence to back up what they're saying. Does your course get into cosmetic science? How things are formulated? What ingredients are used for? And if you doubt what they're saying, why not do your own research -- away from your textbooks -- and see if you can find studies refuting or backing up what they're saying? edit: Oh, look, another link! And it's got sources. http://www.paulaschoice.com/cosmetic-ingredient-dictionary/definition/emollients/mineral-oil