"Use a moisturizer so you don't get wrinkles!" "Put on sunscreen to prevent skin cancer and signs of aging!" Following all the recommended guidelines for skin protection can translate to you slathering product after product on your skin.
However, maybe you've noticed that many moisturizing products also contain sunscreen, which can help cut down on the number of products you should use. Yet why do some moisturizers contain sunscreen and others don't? Is the combined product less effective than if you use both separately?
Before digging into those questions, take a closer look at each of these products separately and see how they protect your skin.
Moisturizer helps hydrate and protect the skin. Without it, the skin can dry out and lose its natural protective barrier. But using a moisturizing product can protect and replenish this barrier, reducing the look of aging signs and keeping skin looking younger [source: Mayo Clinic: Moisturizers]. Moisturizers can hydrate your skin better than water alone because dry, damaged skin can't absorb water very well. It needs a product that traps water on the skin so the cells can better absorb and retain moisture. A number of ingredients found in moisturizers, including glycerin, collagen, elastin, proteins and amino acids, among others, can help the skin rebuild and replenish its outer surface [source: Begoun: Moisturizers].
Sunscreens, on the other hand, are made to protect your skin from the sun's ultraviolet (UV) rays. These invisible rays, whether UVA or UVB, can cause skin damage and increase the risk of developing skin cancer, so experts recommend wearing sunscreen whenever you're outside. Sunscreens come in two different varieties that provide either physical or chemical protection from the sun. Ingredients such as zinc oxide and titanium dioxide help physical sunscreens form an impenetrable layer over the skin that blocks UV rays. Chemical sunscreens include ingredients such as avobenzone or oxybenzone that sink into the skin and absorb UV rays before they can do any lasting damage to the skin. The efficacy of a sunscreen is determined by its SPF, or sun protection factor, which is the percentage of UVB rays the product can filter out. Over time, the sunscreen's ability to protect skin fades, which is why it's important to reapply the product throughout the day [source: Mayo Clinic: Sunscreen].
Now that you know how these products work, let's look at why they aren't always combined into a single product.
Separate Sunscreens and Moisturizers
If you look in the store, you'll find moisturizing products with and without sunscreen in them, often with no difference in price. Since having a sunscreen in a moisturizer can simplify your skin care regimen, it might seem to make sense for all moisturizers to include a sunscreen. However, there are many reasons these products still exist separately.
First, because sun protection is so important, sunscreen may be included in a variety of cosmetics and skin care products. For example, some foundations contain sunscreen, and if yours does, you don't need to have them in both products. If both your foundation and your moisturizer contain an SPF 15 sunscreen, it doesn't mean you've doubled your protection to SPF 30. You've just applied a little extra sunscreen.
Also, sunscreen is necessary only during daylight hours, so when you use a moisturizer at night, it may not make sense to use a sunscreen as part of it. Similarly, there might be times when some parts of your body require only a moisturizer, but not a sunscreen. For example, in the winter, your dry feet probably don't get sun exposure, but still might need a moisturizer.
One interesting difference between moisturizers and sunscreens is that the U.S. Food and Drug Administration classifies these products differently. Moisturizers on their own are considered to be cosmetics, meaning they're applied with the intent of cleaning, beautifying or changing the appearance of the body. Because the active ingredients in sunscreen are designed to prevent disease, they are classified as drugs. Drugs have stricter government regulations and must go through an approval process before going on the market. Cosmetics -- unless they contain certain color additives, which could cause allergic reactions -- usually are not subject to these same stringent guidelines [source: FDA].
What is it in sunscreen that makes the FDA take notice? If you remember from the last page, physical sunscreens often contain titanium dioxide or zinc oxide, which may block pores, irritate skin and increase oiliness. If you already have oily skin, this could be a nightmare for you. Ingredients in chemical sunscreens can also irritate skin in a number of ways, by causing dryness, swelling and redness, for example. People with sensitive skin need to be especially cautious about choosing sunscreen, and moisturizers with sunscreen may have the active ingredients combined in such a way that will irritate certain skin types. This can be a factor in why people will choose separate products [source: Begoun: Sunscreen]. As a result, be sure to understand the active ingredients of the products you use and how they affect your skin.
Learn more about sunscreen, moisturizers and other products to protect your skin by visiting the links on the next page.
Related HowStuffWorks Articles
- Begoun, Paula. "All About Moisturizers." CosmeticsCop.com. (Accessed January 7, 2010.)http://www.cosmeticscop.com/skin-care-facts-moisturizers-state-of-the-art-quality-ingredients.aspx
- Begoun, Paula. "Sunscreen: Sun Protection for Different Skin Types." CosmeticsCop.com. (Accessed January 7, 2010.)http://www.cosmeticscop.com/sunscreen-sunblock-titanium-dioxide-zinc-oxide.aspx
- Mayo Clinic. "Moisturizers: Options for softer skin." (Accessed January 7, 2010.)http://www.mayoclinic.com/health/moisturizers/SN00042
- Mayo Clinic. "Sunscreen: Answers to your burning questions." (Accessed January 7, 2010.)http://www.mayoclinic.com/health/sunscreen/SN00044
- Personal Care Products Council. "Sunscreen and Suntan Products." CosmeticsInfo.org. (Accessed January 7, 2010.)http://www.cosmeticsinfo.org/product_details.php?product_id=47
- U.S. Food & Drug Administration. "Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?)." July 8, 2002. (Accessed January 7, 2010.)http://www.fda.gov/Cosmetics/GuidanceComplianceRegulatoryInformation/ucm074201.htm