Why SPF 50+ Sunscreens Don’t Work the Way You Think

We’ve all seen the rows of sunscreens boasting SPF 70, 85, even 100. It feels intuitive: higher must be better, right? More protection for your skin, less chance of sunburn, safer days outside. But here’s the truth the sunscreen industry doesn’t want you to know — SPF numbers over 50 are often more marketing than science.

In fact, the FDA has even questioned whether these “ultra-high” SPFs should exist at all. If you’ve ever felt invincible slathering on SPF 100 and skipping reapplication, this article is for you.

What SPF Actually Measures (And What It Doesn’t)

SPF stands for Sun Protection Factor, and it only measures protection against UVB rays (the ones that cause sunburn). It does not measure UVA protection (the rays that penetrate deeper, accelerate aging, and can contribute to skin cancer).

Here’s what most people don’t realize:

• SPF 30 blocks about 97% of UVB rays
  
  

• SPF 50 blocks about 98%
  
  

• SPF 100 blocks about 99%
  
  

That’s right — there’s virtually no difference once you go above SPF 30–50. But sunscreen companies use bigger numbers to make you think you’re getting double or triple the protection.

Why SPF Over 50 Can Be Misleading

The danger isn’t the sunscreen itself — it’s the false sense of security. High SPF products trick people into thinking they’re protected all day.

• They reapply less often. Sunscreen breaks down after about two hours, no matter the number on the bottle.
  
  

• They stay out longer in peak sun. Thinking SPF 100 = invincibility leads to more UV damage.
  
  

• They may get more chemical exposure. High SPF products usually require higher concentrations of UV filters (many of which are linked to hormone disruption and environmental harm).
  
  

Even the FDA and American Academy of Dermatology have expressed concerns, noting that SPF over 50 is misleading to consumers and not significantly more protective.

The Safer Alternative: Broad-Spectrum Mineral Sunscreens

Instead of chasing SPF numbers, the smarter choice is to look for broad-spectrum, mineral-based sunscreens.

• Broad-spectrum = protects against both UVA and UVB.
  
  

• Mineral sunscreens (like zinc oxide or titanium dioxide) sit on top of your skin and reflect UV rays, unlike chemical filters that absorb into your body.
  
  

• They’re safer for sensitive skin, kids, and the environment.

What to Look for on a Sunscreen Label

When shopping for sunscreen, here’s what matters far more than “SPF 100”:

• SPF 30–50 (sweet spot for balanced protection)
  
  

• Broad-spectrum clearly listed
  
  

• Mineral active ingredients (zinc oxide, titanium dioxide)
  
  

• Non-toxic formulas free from oxybenzone, octinoxate, and synthetic fragrance
  
  

• Water-resistant if you’ll be swimming or sweating
  
  

Recommended Non-Toxic Sunscreen Brands

Here are a few well-rated, family-safe options to get you started:

• Solara Go! Mineral Defense SPORT Superfruit + Aloe Sunscreen Mist, SPF 30 

• Solara Go! Mineral Defense SPORT Superfruit Body Sunscreen, SPF 50 

• Earth Mama Uber‑Sensitive Mineral Sunscreen Lotion, SPF 40

• Toups & Co Sun Stick

• Toups & Co Sun Balm 
  

The Takeaway

SPF over 50 isn’t “bad” — but it’s not giving you the protection you think it is. What matters more is:

• Choosing a broad-spectrum mineral sunscreen
  

• Reapplying every two hours
  

• Pairing sunscreen with smart sun habits (shade, hats, UPF clothing)
  
  

High SPF numbers may sell more bottles, but they won’t save your skin if you’re skipping the basics. Keep it simple: broad-spectrum, mineral-based, SPF 30–50, and reapply often.