You might be thinking my moisturizer has an SPF 25 and my foundation has an SPF 20, so I’m
getting SPF 45 protection — woo hoo! Sadly, that’s not the case.
25 + 20 ≠ 45
First off, good for you for knowing that daily sun protection is a must, even on a cloudy day. You’re already off to a great start when it comes to taking good care of your skin.

Applying multiple SPF products is a good practice, but here’s the reality: SPF numbers do not add up to give you more protection. You WILL get the highest sun protection factor you have applied, however. So in this example, you’ll get an SPF 25 from your moisturizer.

Merle Norman SPF stars: MERLE NORMAN Dual Spectrum®, PREVENTAGE™ Firming Defense Creme Normal/Oily, PREVENTAGE™ Firming Defense Creme Normal/Dry, Lip Conditioner SPF 15, Sheer Defense, Flawless Effect Liquid Foundation SPF 15, Lasting Foundation, Timeless Age Defying Makeup SPF 20, Liquid Makeup SPF 16.