Sunflower seed oil actually strengthened the skin barrier and improved hydration without causing irritation, while olive oil weakened the barrier and triggered redness after just 4 weeks of twice-daily use. This held true even for people with a history of sensitive skin. The takeaway: not all natural oils are created equal for skin.

Researchers had 19 adult volunteers apply oils to their forearms for 4-5 weeks and measured barrier integrity, hydration, and irritation. They tested both oils on the same people to get direct comparisons.

Funding not disclosed in abstract