"Go for a glycerin moisturizer," says Linda Rhein, a biochemist with Bayer HealthCare Pharmaceuticals and editor of the book Aging Skin: Current and Future Therapeutic Strategies.
"It really moisturizes very well, holds the moisture in the skin," she says. Since it seals in moisture, it's good to use right after a bath or shower.
It's unclear whether other additives to moisturizers — such as antioxidants, vitamin A (retinol), CoQ10 and vitamin C derivatives — reduce wrinkles or improve the look of skin, dermatologists say. Though studies show why they could help, there aren't long-term studies showing they do, says Rhein.
Take, for example, vitamin C: The molecule changes so much when added to lotions or creams it may not remain intact. Also, the body has to convert the vitamin C in some products to a form it can use, and whether the body does that is also unclear. The problem with the vitamin A derivatives in over-the-counter moisturizers is the low or unknown concentration. For those to work they need to be prescription strength.
Referring to her study last year that found evidence to support a potential role for vitamins A, C, E and B3 in skin care, dermatologist Jenny Kim, an associate professor at UCLA, said in a press release, "While it's evident that these vitamins can play a role in fighting sun damage, the question still remains whether these properties are effective when delivered in skin care products."
Money doesn't buy better results
Consumer Reports found that the serums and eye creams it tested had little to no effect, and that, as with all cosmetic products and procedures, results varied considerably among individuals. Also, higher prices don't necessarily mean better quality.
"Many cosmetic products are expensive and their price in the store has no relation to their content," Johann Wiechers, a cosmetic scientist and founder of JW Solutions, an independent cosmetic science consultancy, wrote in an article for an online industry magazine.