Our first line of defense is usually some kind of cream. You’ve probably noticed that companies make several versions of any given product (cream! lotion! serum!) — and, to most cosmetics shoppers, those words connote the age/skintype of the intended user. The words don’t actually have standard, scientific definitions, but the textures they describe are fairly consistent.
1) Lotion – Thin liquid, usually oil mixed with water (and oil doesn’t mean bad). It spreads when it’s out of its container.
2) Cream – Thicker than a lotion, about a 50-50 mixture of oil and water. It holds its shape when it is out of its container.
3) Ointment – Very thick, often occlusive, possibly greasy substance; about 80% oil and 20% water (e.g., Vaseline petroleum jelly)
4) Gel – Also a semi-solid substance, but generally alcohol-based rather than oil-based
5) Serum – Usually a product containing a higher concentration of an ingredient found in a cream or lotion. Most cosmetics companies say these are formulated for greater penetration through the skin, with greater concentrations of active ingredients, and are lighter/less emollient than a cream. But the word doesn’t have a standard accepted definition as far as I can tell.
Of course, what makes any topical solution work (or not work) is the ingredients.
An anti-aging product may contain many ingredients. Most of these are not the active ingredient — they may be preservatives, oils, fragrance… these are both the vehicle for the active ingredient, and components that create the user experience (feel, texture, scent, etc.).
There are several types of ingredients to look for in any given product: moisturizers or hydrating agents (self-explanatory), antioxidants (which counteract the effects of cell-damaging Reactive Oxygen Species that are produced by UV light and smoking), and cell regulators (which can stimulate cells into behaving more like young skin). Some of these ingredients have been shown to be effective at reducing wrinkles and other visible signs of aging through clinical trials.
A side note: all clinical trials are not created equal. Just because a trial showed that a product or ingredient had a “significant” effect on signs of aging does not mean that it will work for you. Clinical trials frequently suffer from methodological problems (small number of patients, short duration of use of the product, patients who withdraw from the study, lack of placebo, randomization, or blinding, etc.). Furthermore, an ingredient might have been found to be effective for a specific type of person or in specific doses, and those results may not apply to you, or the specific product you are using. It takes some amount of expertise to analyze a study. Fortunately, there are several watchdog groups out there (the Cochrane Library and the British Medical Journal’s Clinical Evidence group are two of the best known).
Moisturizers improve the barrier function of the epidermis (preventing the skin from losing moisture), and rehydrate it (which can reduce the fine wrinkles that are seen in dry skin). A few common, effective moisturizers include urea, ammonium lactate, and lactic acid. There are also natural moisturizers, like shea and cocoa butter etc.
Hyaluronic acid is another ingredient marketed as a humectant, to rehydrate the skin. When injected, it is quite effective at rehydrating skin and reducing wrinkles (it is also used as a filler, a topic we’ll take take on later in this series). Creams containing hyaluronic acid are less effective, mainly because they don’t penetrate the skin as well, but there are studies that show they still work.
Now, anecdotally, I’ve seen serums perform well in conjunction with other creams, but they often aren’t “enough” on their own. I think the serums I’ve used contain humectants (like hyaluronic acid, which draw water into the cells), but not moisturizers. I guess you can’t put moisturizing ingredients into a product and still achieve a “serum” consistency. But why don’t they put the serum ingredients into the moisturizer?
Effective antioxidants are: Vitamin C (or ascorbic acid/ascorbate), Vitamin B3 (or niacin, nicotinic acid, nicotinamide, niacinamide), Vitamin E (or tocopherol), Lipoic Acid (or Alpha lipoic acid), Green tea extract (or Camellia sinensis), Flavonoids, and Reservatrol. All of these ingredients are thought to slow down skin aging by neutralizing any reactive oxygen species they find, preventing damage to skin components.
Effective cell regulators are: Palmitoyl pentapeptide, Argireline, Madecassoside (or Centella asiatica), and Salicyloyl-phytosphingosine. These ingredients are thought to directly signal dermal and epidermal cells to change their behavior (to produce more collagen and elastin for example).
Alpha hydroxy acids (glycolic acid, lactic acid, citric acid, malic acid, and tartaric acid) and Beta hydroxy acids (salicylic acids) are commonly used in chemical peels — and in the high concentrations seen in peels, they have been shown to be effective at increasing epidermal turnover and improving dermal thickness. In the lower concentrations you find in over-the-counter products, there is no conclusive evidence that they are effective anti-agers. (Though they’re still effective exfoliators, removing the top layer of epidermis.) These chemicals are a little bit of a mix — they have some antioxidant properties, some cell regulation, and also directly cause epidermal turnover by sloughing off the top layers of epidermis.
One other interesting cell regulator (which has been shown in some studies to reduce the appearance of wrinkles) is estrogen and progesterone. Estrogen restores skin thickness, and enhances production of collagen, elastin, and hyaluronic acids. One study used 2% progesterone cream and found that it improved skin elasticity, wrinkles, and skin firmness after 16 weeks of treatment, in women who were either close to menopause or post-menopausal. Another used 0.01% estradiol for 6 months and found similar results. I actually want to dedicate a separate article to estrogen/progesterone, because I had about a million questions about efficacy and side effects (and there’s a relatively new phyto-estrogen line on the market, called VenEffect).
Antioxidants and Cell Regulators
There’s one more set of ingredients to talk about. They don’t fit neatly into just one of the aforementioned categories, because they’re both antioxidants and cell regulators. They have also definitely been found to be effective at reducing wrinkles, irregular pigmentation, or roughness — they also require a prescription. They are Tretinoin (other similar forms include Vitamin A, Retinol, and Retinoic Acid), Isotretinoin (Accutane), and Tazarotene (Tazorac). All three of these are used for acne treatments as well — they increase cell turnover in the epidermis, stimulate formation of new collagen in the dermis, and improve the border between the dermis and epidermis.
What Have We Learned?
I hope you’ll find it a little easier to interpret the ingredients in your moisturizer. I also think it’s okay to be skeptical if a product’s claims aren’t in line with its ingredient list. But ultimately, the process of finding a moisturizer you love is going to include some trial and error. Everyone’s skin is different, so even if a study shows a product works for 75% of people, that doesn’t mean it’s going to work for you. And if it only works for 25% of people, it may work for you. If you find something you love, hang onto it! (But maybe there’s something else out there with the same ingredients that’s cheaper.) And always wear sunscreen.
Next week: Lightening and brightening creams
1. Clin Evid (Online). 2008; 2008: 1711. Wrinkles. Manríquez JJ, Gringberg DM, Diaz CN
2. The Cochrane Library. 2009. Interventions for photodamaged skin. Samuel M, Brooke R, Hollis S, Griffiths CEM
3. Clinics in Dermatology. 2012, 30(3). Effect of moisturizers on epidermal barrier function. Lodén M
4. Journal of Drugs in Dermatology 2011:11. Efficacy of cream-based novel formulations of Hyaluronic acid of different molecular weights in anti-wrinkle treatment.Pavicic T, Gauglitz GG, Lersch P, Schwach-Abdellaoui K, Malle B, Korting HC, Farwicka M.
5. British Journal of Dermatology; 2005:153(3). Effects and side-effects of 2% progesterone cream on the skin of peri- and postmenopausal women: results from a double-blind, vehicle-controlled, randomized study. Holzer G, Riegler E, Hönigsmann H, Farokhnia S, Schmidt B.
6. Am J Clin Derm. 2011:12(5). Estrogen and Skin Therapeutic Options. Shu YY, Maibach HI
7. J Cosm Derm 2008. Anti-aging properties of resveratrol: review and report of a potent new antioxidant skin care formulation. Richard A Baxter, MD
8. Br J Derm 2003. Randomized, placebo-controlled, double blind study on the clinical efficacy of a cream containing 5% ot-lipoic acid related to photoageing of facial skin. Beitner H
9. Exp Derm 2008. Clinical, biometric and structural evaluation of the long-term effects of a topical treatment with ascorbic acid and madecassoside in photoaged human skin. Haftek M, et al
10. Int J Cosm Sci 2005. Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin. Robinson et al