by Vicky Uhland
In mainstream personal care, a product's image can be just as important as its ingredients. While naturals shoppers like to think they're immune to all the posh names and flashy packaging, they are human, after all. Many want hope in a bottle just as much as a department-store shopper does. That's one reason why naturals manufacturers are debuting products that rival the high-end lines not only in terms of effectiveness but also regarding formulations and packaging.
One of those fancy formulations is serums. Long a staple in department-store lines, serums are making their way into some naturals lines as well. But this can pose a problem for you and your customers: Just what are all those serums supposed to do? Are they moisturizers? Should they be used instead of a cream? Do they work for every skin type? In every climate?
Serums are lighter and more concentrated than creams, says cosmetic chemist Marilyn Patterson, head of research development for Natural Cosmetic Solutions, an Acton, Ontario, Canada-based formulator for natural personal care companies. Serums also have more active ingredients, she says. As a result, "Serums are focused on a specific condition, like skin repair, acne, rosacea, aging— something someone wants an additional product to address."
Unlike a serum, a cream needs to work for a wider variety of skin types and conditions. Think of creams as the minivan of cosmetics, adaptable to many different uses, and serums as the sports car— built for one use only, but highly effective. "A serum is going to do something that the cream's not going to do," Patterson says.
Although serums can be oil-based, they're usually made with water, which allows them to have fewer ingredients than creams, Patterson says. A cream generally needs emulsifiers to hold its oil and water ingredients together, as well as thickeners, stabilizers and "things to make it feel good, smell good. A lot of its ingredients have to do with aesthetics," she says. Because a serum is much less generalized in its focus, it may only have a few ingredients. "Almost everything in a serum is 100-percent active— when I'm making a serum, I don't use anything that doesn't benefit your skin," Patterson says.
Serums also can contain exotic or more expensive ingredients such as superfruit extracts or Co-Q10. "I'll add things I don't use all the time in my other formulations," Patterson says. The result? Often, higher price tags for serums than creams.
Not everything that goes into a cream can be added to a serum, Patterson says. "Some ingredients that are good in oil would oxidize in water. Water is also more conducive to bacteria and mold, so you may need preservatives in a serum you wouldn't need in a cream." On the other hand, she says, "It's not like you can stick everything into a cream, either." That's why manufacturers often recommend using a serum and cream together, to get the benefits of both.
In a study published in the March issue of International Journal of Cosmetic Science, Belgian researchers found that serums showed good skin hydration and firming results immediately after application, but creams delivered better long-term results, particularly in terms of hydration.
The researchers hypothesized that serums immediately hydrate the skin because of their high water content. Water-based serums are designed to penetrate quickly into the face, with the goal of carrying the serum's active ingredients into the skin before the water evaporates. "The idea is that these viscous serums have a smaller molecular structure than creams, allowing the ingredients to penetrate better," says Alison O'Neil Andrew, an Atlanta-based aesthetician and founder of the Beauty Becomes You Foundation, a nonprofit personal care service for seniors. "The theory is that the skin will accept more benefits of a product if it's hydrated."
But are serums always as penetrable as they claim to be? It depends on the formulation, Patterson says. "Aqueous things don't always go into the skin that easily. If you put a cream on top of the serum, it holds the serum in next to the skin so it can penetrate." The cream essentially serves as a barricade, protecting the skin, blocking in moisture and allowing the serum to work, she says. Andrew says hyaluronic acid, which is found naturally in the body and is used in anti-aging formulas, works well in a serum because it can easily penetrate the skin. The Belgian researchers also found that marine extracts in serums improved the skin's hydration and firmness.
There are times when it's best not to use a serum and cream together. Patterson says people with oily skin might want to use a light day cream at night and an antioxidant or acne serum during the day to protect and treat the skin without adding extra oil that could clog pores. A serum may be enough moisture in a humid climate as well, where creams tend to stay gooey and uncomfortable on the skin, she says.
People with normal skin in normal weather conditions may not need a serum at all, unless they have a specific condition they want to treat, Patterson says. But those with dry skin or who live in harsh climates probably need serum and cream's one-two punch, says Kimberly Sayer, an aesthetician and creator of the Kimberly Sayer of London natural skin care line. "If you're outside a great deal, if it's winter or windy, a cream can protect or hydrate along with the serum."
Women whose skin is dry because of hormonal changes during pregnancy and menopause may also want to use a cream and serum, Sayer says. Serums also give a great finish to the skin, making them good under makeup. "A lot of models love using serums alone because it creates more of a flat, matte finish to the skin," she says. "They use the serum during the day and a night cream at night."
Vicky Uhland is a Lafayette, Colo.-based freelance writer and editor.
Natural Foods Merchandiser volume XXVIII/number 6/p. 60