Zinc Oxide
Zinc oxide is a mineral sunscreen filter — it sits on top of the skin and physically reflects UV rather than absorbing it chemically. Since every pigmentation and anti-aging active in this list is undone by unprotected sun exposure, this is arguably the single highest-leverage ingredient on the page.
How to introduce it
7x
Starting / week
7x
Target / week
—
Ramp period
1w
Fair to judge by
Rules that don't bend
- Every morning, no exceptions — this is what makes every other active safe to use.
- Reapply after 2+ hours of direct sun exposure.