All things SPF
August 31, 2026
Why Sunscreen Belongs in Your Morning Routine
Sunscreen works on consistency, not intensity. Here is why a moderate SPF worn every morning beats a high one worn occasionally, where...
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August 18, 2026
Naturally Derived, and Only Five: How Swellies Built a Sunscreen From Minerals and Plants
All five Swellies ingredients are naturally derived, from minerals and plants. Not as a wellness claim, but because those were the right...
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August 11, 2026
When Should You Start Wearing Sunscreen to Prevent Skin Aging?
Up to 90 percent of visible skin aging is UV exposure, not age, and it is driven by UVA you never feel....
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August 06, 2026
Zinc Oxide Absorbs UV Light. It Does Not Absorb Into You.
Zinc oxide absorbs UV below about 375nm and scatters the rest. The mechanism, what SPF it can reach, and what particle size...
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July 30, 2026
The First New Sunscreen Filter in Decades, and How It Compares to Zinc Oxide
In June 2026 the FDA authorized bemotrizinol, the first new sunscreen filter in about twenty years. It is good news for the...
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July 25, 2026
The Real Dangers of DIY Zinc Oxide Sunscreen
A homemade formula with 25% zinc oxide measured SPF 7 at an independent third-party lab. The ingredients were not the problem. Dispersion...
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July 17, 2026
Micro-Tint: How Japanese and Korean Sunscreen Cracked the Code for (Almost) Every Skin Tone
The white cast is a Western mineral problem. Japanese and Korean formulators solved it with micro-tint, a low level of iron oxides...
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July 11, 2026
Sunscreen Ingredients to Avoid During Pregnancy
Some chemical UV filters absorb into the bloodstream, and the FDA has asked for more safety data on them. Here are the...
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July 02, 2026
Why Does Sunscreen Smell? Three Reasons, All Optional
Most sunscreen smells because of chemical filters, added fragrance, and oils going rancid. Swellies has none of them. Five ingredients. No smell.
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