A simple at-home check:
It can be either. Dry skin looks dull because it lacks moisture and flakes build up. Oily skin looks dull when the oil traps dead skin, creating a congested, uneven surface. Dullness is a texture + hydration issue — not a skin-type issue.
The big three are:
Yes. Stress increases cortisol, which slows down collagen production, disrupts your skin barrier, and makes hydration evaporate faster. The result: skin looks tired, flat, and sometimes even slightly grey. Stress also affects sleep, which directly impacts radiance.
Dullness usually means one (or a combination) of three things:
Most commonly, low omega-3s, iron, vitamin B12, and vitamin D can contribute to dull, fatigued-looking skin. These deficiencies don’t cause texture issues on their own, but they can make the skin look flat, pale, or less glowy because they affect circulation and cell turnover.