Just what is mineral makeup? If you've opened a fashion magazine, you've seen an ad for these soft, shimmery cosmetics. Worn either as foundation or setting powder, mineral makeup gives the skin matte (no-shine) coverage and a natural-looking finish. And thanks to the sunscreen ingredients zinc oxide and/or titanium oxide in many formulations, mineral makeup can also supplement sun protection.
What's In It?
Mineral makeup is loose or pressed powder consisting of naturally occurring inorganic materials such as bismuth oxychloride, boron nitride, mica, talc, titanium dioxide and zinc oxide - minerals.
For extended wear, mineral makeup should ideally be used in addition to rather than instead of a separate SPF 15+ sunscreen product
The makeup is popular due to its downy texture (which comes from boron nitride, corn starch or talc); shimmery colors (provided by iron oxides and mica); adhesive abilities (from bismuth oxychloride, boron nitride, and magnesium stearate), and absorbent qualities (properties of bismuth oxychloride and kaolin clay).
Some mineral formulas also include silicones: stable and water-repellent compounds with high molecular weights. Silicones such as dimethicone, cetyl dimethicone and trimethylsiloxysilicate act as emollients and moisturizers, softening and adding hydration to the skin. Sometimes trace amounts of antioxidants or provitamins are added to the blend, too.
Mineral Makeups as Sunscreen
Titanium dioxide and/or zinc oxide are the keys to the sun protection offered by such makeups. These inorganic, insoluble minerals are considered "physical sunscreens," and they work by reflecting the sun's ultraviolet radiation (UVR) away from the skin, as opposed to chemical/organic sunscreens, which absorb rather than reflect UVR.
"For incidental exposure - if you go out for a short while - mineral makeup used without a separate sunscreen is fine if the makeup's SPF is at least 15," says Diane S. Berson, MD, Associate Professor of Dermatology at Weill Medical College of Cornell University in New York City.
When you're planning to stay out in the sun for longer than 15 minutes, "Mineral makeup with SPF can enhance your protection if layered over a sunscreen product," explains Leslie Baumann, MD, Director of the Cosmetic Dermatology division at Miller School of Medicine, University of Miami. The powder, applied on top of sunscreen, will probably catch any spots you may have missed.
One problem with mineral makeup - as with all sunscreens - is that consumers usually apply less than recommended for greatest efficacy. To evaluate a product's SPF, testers apply two milligrams of sunscreen per square centimeter of skin, but this is extremely difficult for sunscreen users to replicate. As Warwick L. Morison, MD, Chairman of The Skin Cancer Foundation's Photobiology Committee, observes, "I would guess that people use about a quarter as much" as the testing protocols. However, he notes, "People might actually use more mineral makeup" than they do sunscreen, possibly providing more protection.
For extended wear, mineral makeup should ideally be used in addition to rather than instead of a separate SPF 15+ sunscreen product, says Arnold W. Klein, MD, UCLA Professor of Medicine and Dermatology.
When applied, mineral makeup's finely ground particles cling to the skin's surface. However, Dr. Berson observes, "The coverage can vary based on application method and consistency." "Brushes tend to produce more scattered coverage," Dr. Berson says. "If you apply more cohesive [pressed] powder with a finger or pad, it is more concentrated and hence more protective." And Dr. Baumann reiterates, "Layer [mineral] powder over sunscreen - remember, sunscreen first!"