Occlusives form a seal on top of skin so water can’t escape. Petrolatum (Vaseline), lanolin, waxes, dimethicone at higher concentrations.
The heaviest, least glamorous, most effective category for genuinely dry skin. “Slugging”, a thin layer of petrolatum as the last step at night, is just occlusion with a nickname. Skip it if you’re acne-prone and it’s June.
How the three work together: humectants bring water in, emollients smooth the surface, occlusives lock the door. A good moisturiser is usually all three in one tube, which is why “do I need a separate hyaluronic acid serum” is a fair question, and the honest answer is often no.
The BYOUT Library is educational content, not personalised medical advice. For persistent or severe skin concerns, a dermatologist beats any article, including ours.