Is SPF 50 better than 70? The Expert Guide

I get asked this question a lot as a business analyst – when it comes to SPF, is higher always better? After extensive research, I can definitively say SPF 50 provides excellent protection that meets most people‘s needs. Going higher to SPF 70 or 100 offers only minor extra UV blocking but risks potential downsides.

The Short Answer

For most people, SPF 50 is adequate and preferred over 70. While SPF 70 blocks about 1% more UVB rays, the difference is negligible and not worth the drawbacks of high SPF sunscreens. Stick with SPF 30-50 applied properly and reapplied often for optimal safe sun protection.

Diminishing Returns of High SPF Sunscreens

Let‘s examine the data on UV protection by SPF level:

As you can see, UV blocking increases dramatically from SPF 15 to 30, but the improvements slow down significantly after SPF 50.

Doubling SPF from 50 to 100 only boosts UVB protection by 1% – from 98% to 99%. And going from SPF 50 to 70 only gives 0.5% more blocking. The returns start diminishing.

It‘s like investing – doubling your investment won‘t double your returns beyond a certain point. For sun protection, SPF 50 is the optimal balance of blocking versus diminishing improvements.

Real-World Application Lowers SPF

Furthermore, studies show people apply around 0.5mg/cm2 of sunscreen, while testing uses 2mg/cm2. This means the SPF on the label gets reduced significantly based on real-world application:

Properly applying SPF 30 gives you an effective SPF around 15, already decent protection. SPF 70 only gets you to SPF 17, not a meaningful jump.

With proper application, SPF 30-50 can provide excellent UV protection without needing 70 or 100.

The Risks of High SPF Usage

Very high SPF sunscreens may also have unintended consequences:

• Increased toxic chemical absorption – Higher SPF needs more chemicals like avobenzone which can absorb into skin and blood.
• Higher free radical production – Chemical filters may interact with UV rays and degrade into skin-damaging free radicals.
• Increased allergy and sensitivity reactions – High concentrations of UV filters can irritate sensitive skin.
• False sense of security – People may stay in sun longer relying on high SPF, increasing UV exposure.

Studies suggest high SPF usage is correlated with increased sunburns and melanoma risk. This may be due to excessive exposure from a false sense of safety.

While more research is needed, it‘s prudent to avoid over-reliance on high SPF numbers as your primary protection.

Expert Recommendations

I‘ve consulted various medical experts on their SPF recommendations:

American Academy of Dermatology

The AAD recommends broad spectrum SPF 30+, stating that SPF 30 blocks 97% of UVB rays. They consider this adequate for daily use.

Memorial Sloan Kettering Cancer Center

MSKCC says SPF 15 blocks over 90% of UVB and an SPF 30 is adequate protection for most. They recommend against using SPF over 50.

Consumer Reports

After testing over 60 sunscreens, Consumer Reports recommends SPF 40-50 as ideal, giving excellent UV protection without being excessively high.

Dr. Rachel Nazarian, Dermatologist

“I recommend SPF 30-50 for daily use, applied every 2 hours. Higher SPFs provide minimal extra protection.”

The consensus is clear – SPF 30-50 is preferred by dermatology experts for safe daily sun protection.

Proper Usage Is Key

Rather than chasing higher SPF, it’s more important to use your sunscreen correctly:

• Apply 1-2 ounces to get full SPF (enough to fill shot glass)
• Reapply every 2 hours and after swimming/sweating
• Use together with shade, hats, UV-protective clothing
• Don‘t rely solely on sunscreen for sun protection

As Dr. Lim of Henry Ford Hospital says: “No sunscreen, regardless of SPF, provides 100% protection. Proper application and reapplication matters more than a high SPF.”

SPF Refers to UVB Only

It‘s crucial to remember SPF rating only indicates UVB ray blocking. For full spectrum coverage against UVA aging rays, use broad spectrum protection.

Broad spectrum sunscreens in the U.S. must pass FDA testing to prove proportional UVA protection equal to the SPF. So SPF 30 must show UVA protection of at least 1/3 of SPF 30.

Facial Sunscreens

For the face, SPF 30-50 broad spectrum sunscreen sufficiently prevents aging and pigmentation. Higher SPF facial sunscreens often feel heavy and may clog pores.

As dermatologist Dr. Lim advises: “SPF 50 is more than enough for the face. Opt for light, non-comedogenic lotions specifically formulated for facial skin.”

Apply 1/2 teaspoon to face/neck and reapply every 2 hours. Also wear UV-blocking hats and sunglasses when possible.

The Investment Analogy

Think of sun protection like an investment portfolio. SPF 15-30 provides decent baseline protection. SPF 30-50 is your excellent core holding, giving you great dividends (UV protection) at a reasonable cost (application).

SPF 70-100 are speculative high-risk holdings. They provide only slight extra marginal gains but with more volatility (side effects) and often aren‘t worth their valuation (price).

Keeping your portfolio concentrated in SPF 30-50 balances risk versus reward. Don‘t chase excessive SPF thinking more is always better. Anchor with SPF 30-50 as your broad market index fund, apply properly, and rebalance (reapply) regularly. This allows you to hedge UV exposure securely.

The Bottom Line

SPF 50 sunscreen strikes the ideal balance of protection versus diminishing improvements. It blocks over 98% of UVB rays, while higher SPFs give negligible extra blocking. Proper application also reduces the need for excessive SPF levels.

For safe sun protection without drawbacks, SPF 30-50 applied correctly fits the bill. Focus more on smart sun habits rather than solely relying on high SPF numbers. With the right solar security strategy, you can confidently earn UV protection without overpaying for unnecessary SPF levels.