Sunscreen Guides

Last updated September 28, 2026

Question-led guides that pull the research on a single decision into one place. Each one leads with the answer, names the studies behind it, and says plainly where the evidence stops.

All Guides

Which Tinted Sunscreen Is Best for Melasma? The Iron Oxide Evidence
Iron oxides give a tinted sunscreen its visible-light protection — and in a randomized melasma trial, only the tinted SPF 50+ significantly reduced melasma colour contrast over a summer; the untinted SPF 50+ did not.
Which Tinted Sunscreens Contain Iron Oxide? Every Label Checked
22 tinted sunscreens sold in the US whose labels name iron oxides, with the filter type behind each tint and what the label does not prove.
Highest SPF Natural Oil - Understanding the Research and Reality
Which natural oil really measures highest, and why the widely-quoted numbers do not survive lab testing.
Is SPF 100 Better Than SPF 50? What Head-to-Head Trials Show
Randomized split-face trials, what the diminishing-returns maths leaves out, and what matters more than the number.
Nano Mineral Sunscreens - Transparency and Safety
Particle size, the transparency trade-off, and what penetration studies found for nano zinc oxide and titanium dioxide.
Zinc Oxide + Titanium Dioxide SPF 30-50+
Why the two minerals are combined, and how the pairing reaches SPF 30-50+ that neither reaches alone.