Is a combination sunscreen and moisturizer a good idea?

Iammao inquires…I typically use a separate SPF product to have better control of my skincare routine and reliable SPF coverage. However, due to recent changes in my schedule I have been tempted to use day creams with integrated SPF for convenience. I have started with La Roche Posay’s Hydraphase Intense UV which claims to have SPF20. Additionally, I practice all other sun safety measures. My main concern is, how do I know how much to use? Do I dispense the same recommended quantity as sunscreens? Is it safe to use the same amount I would use for a moisturiser? Is this form of sun protection reliable at all?

The Beauty Brains respond:

When it comes to sunscreen, size matters. The size of the dollop of lotion that you apply to your face, that is.

If you’re relying on a foundation to provide sun protection then you need to apply just as much of this product as if you were applying a regular sunscreen. And, according to reliable sources like Skincancer.org, that means about a nickel-sized dollop to the face alone. As you noted, using separate products gives you better control and makes it easier to ensure you’re getting to the proper SPF. Using a combination product almost ALWAYS involves compromise. In this case,  there’s not much downside because the worst that can happen is that your skin will end up too greasy. But if you were to use a combination sunscreen and foundation, you might find that you’re applying way too much pigment to your face in order to get the required SFP.

La Roche Posay’s Hydraphase Intense UV ingredients

Active: Avobenzone (3%), Octisalate (5%), Octocrylene (7%), Other: Water, Isononyl Isononanoate, Glycerin, Dimethicone, Diisopropyl Sebacate, Aluminum Starch Octenylsuccinate, Sucrose Tristearate, Polysorbate 61, Zea Mays (Corn) Oil, Tocopheryl Acetate, Sodium Stearoyl Glutamate, Sodium Hyaluronate, PEG-12 Dimethicone, Triethanolamine, Dimethiconol, Panthenol, Xanthan Gum, Caprylyl Glycol, Carbomer, Passiflora Edulis Seed Oil, Disodium EDTA, Prunus Armeniaca (Apricot) Kernel Oil, Oryza Sativa (Rice) Bran Oil, Tocopherol, Ascorbyl Palmitate, Methylparaben, Phenoxyethanol, Fragrance