What Works
New Beauty Intelligence
Skip Sunscreen Now, Pay Later
People who understand that they are at risk from skin cancer and aging are more motivated to protect themselves. According to a UV Exposure Survey,19 once patients realize the extent of their unanticipated sunexposure, they agree to use sun protection regularly rather than just at the beach.
Intermittent use of sunscreen is not enough to protect skin from sun damage. Studies indicate that even modest increases in exposure adversely affect skin's function and appearance.
• In a study published by Phillips, et al.,20 skipping sun protection on one day out of four was enough to lower the skin's defense mechanisms and increase endpoints related to photoaging, e.g., lysozyme staining.
• Skin expert Greg Hillebrand monitored photoaging in two cities with a 1.5 times difference in the annual average UVB exposure.21 After one year, those exposed to higher radiation had aged visibly and had rougher, drier skin, larger and more age spots and had significantly more wrinkles.
A Little Dab Won't Do - Sunscreen Application in the Real World
Dermatologists encourage photoprotection. Studies show that people are aware of the risks, but few regularly use UV protection. Additionally, those who douse sunscreens regularly rarely apply the proper amount. Studies have found that people typically useonly half the amount they need for full protection. This is believed to be a result of product aesthetics and having an incomplete understanding about SPF and what it really means.22
Properties that might be desirable at the beach (rubproof and waterproof) would not be necessary in a daily facial moisturizer where aesthetics of the product are key and highly desirable. The formulator's art is in balancing efficacy and aesthetics.
To improve use, P&G Beauty scientists studied how human behavior affects efficacy. They observed that SPF products in lighter formulations tend to be used more regularly and applied more generously.23
The FDA standard dose for SPF testing is a sunscreen application of 2 mg/cm2, which equals an estimated 28.47 grams of sunscreen to cover the entire body or the amount to fill a shot glass.24
Poorly formulated high-SPF products are frequently misused because they don't spread easily and feel heavy, occlusive, "hot" and greasy. In a week-long, double-blinded sunscreen usage test comparing consumer application habits when using SPF 30 versus SPF 15, researchers found that:25
• Heavy feeling products with a higher SPF were applied much more sparingly
• Cosmetically formulated products with a lower SPF were used more consistently
Sunscreen Beauty (and Health!) Secrets
• Aesthetics drives compliance. Those using daily protection are more likely to consistently use facial moisturizers with an SPF 15 or 30 that readily"disappear" upon application.
• Recreational products are best for beach time, sports or extreme sun exposure. Although cosmetic products are preferable for daily use since they tend to have lighter, less greasy aesthetics, they are not waterproof or sweatproof. The correctwater and rub resistant formulations should be used for extended sun exposure. Special care should be taken to reapply in order to achieve adequate protection.
• Quantity and frequency of reapplication arethe best protection. Those requiring the highest level of protection or anticipating a high level of UV exposure need to apply sunscreen generously and then reapply sunscreen after dry down. This method provides a continuous and complete sunscreen film, helping to increase efficacy.
Did You Know?
Many Wrinkles in Time
• Glass doesn't block UVA. Glass filters UVB, but if light shines through, so does UVA.
• High altitude increases solar radiation exposure.
• The two most effective UVA blockers in the U.S. are avobenzone, a chemical that absorbs light, and zinc oxide (ZnO), a mineral that scatters and absorbs light. These ingredients can be formulated for excellent skin feel as well as efficacy.
• Titanium dioxide (TiO2) is also FDA-approved toblock UVA. Efficacy delivered from titanium dioxideis formulation dependent. TiO2 products can leave skin feeling coated and with a white appearance, which is not desirable.
• Self tanners are not protective. They develop color on the skin's surface via a chemical reaction.
• The SPF number does not represent a specific length of time. It represents a variable duration -the time it takes for skin to turn pink - which depends on individual skin characteristics and intensity of exposure. Specifically, SPF equals the minimal erythemal dose with sunscreen divided by the minimal erythemal dose without sunscreen.