Over-the-Counter Topical Skincare Products: A Review of the Literature

This antioxidant has been shown to speed wound contraction and closure.³² Topically, it also has been shown to protect against UV radiation in humans.³³ Interestingly, a 2011 study found that oral use of grape seed extract was associated with a significantly decreased prevalence of squamous cell carcinoma.³⁴

Although these grape compounds show promise as effective actives, in vivo studies need to be conducted to further evaluate their effects on photoaged skin.

These naturally occurring organic compounds in soybeans can act as phytoestrogens in mammals. Several studies have shown that oral soy isoflavones can improve skin appearance, especially in postmenopausal women. There is little literature supporting their role in improving skin appearance topically, but they have been shown to protect against UVB radiation.³⁵

Green tea has long been thought to be associated with various health benefits ranging from decreased risk for heart disease to weight loss. Some recent research has shown that polyphenols from green tea as well as white tea can suppress carcinogenic activity from UV radiation.³⁶

However, another recent study found that histopathologic analysis of sun-exposed skin treated with topical green tea polyphenols showed no statistically significant difference in photoaging parameters compared with placebo. Moreover, the green tea-treated group actually had significantly more wrinkling from baseline compared with the placebo group. Overall, there seems to be conflicting literature on the function of green tea polyphenols, and more comprehensive studies are needed.³⁷

Extracts from C. arabica berries, which are used in the production of coffee, contain polyphenols. They have stronger antioxidant properties than pomegranate, vitamins C and E, and green tea. In a vehicle-controlled blinded study, C. arabica was shown to improve fine lines, skin texture, and skin pigmentation. Interestingly, extracts from the leaves (caffeine) has been used to reduce undereye puffiness and temporarily improve the appearance of cellulite.³⁸

Dimethylaminoethanol (DMAE) is an analog of choline and a precursor of acetylcholine. A 2005 study showed that a 3% DMAE facial gel applied daily for 16 weeks reduced forehead lines and periorbital fine wrinkles.³⁹ The formulation also improved lip shape and fullness and the overall appearance of aging skin. A more recent study in both hairless mice and human skin showed that a DMAE-supplemented formulation led to increased dermal thickness, and DMAE also induced an increase in collagen fiber thickness.⁴⁰ Formulations both with and without DMAE enhanced the stratum corneum water content in forearm skin.

There are a multitude of studies evaluating specific active ingredients, yet there are few studies of OTC formulations, which are often a mixture of many ingredients. Although there is a significant lack of rigorous trials of efficacy for these products, we review the existing literature on OTC formulations below.

A 2009 study¹² evaluated the No7 Protect & Perfect Intense Beauty Serum by Alliance Boots (a water-in-silicone emulsion with glycerin, emollients, and ingredient complex comprising sodium ascorbyl phosphate, Panax ginseng, Morus alba, Lupinus alba, tocopherol, palmitoyl oligopeptide, palmitoyl tetrapeptide- 7, Medicago sativa, and retinyl palmitate). This is one of very few studies evaluating an OTC cosmetic “anti-aging” product with a rigorous double-blind, vehicle-controlled trial of efficacy. This study effectively showed that an OTC product can cause fibrillin-1 deposition and may have the potential to repair and clinically improve photoaged skin.

Sixty photoaged subjects were recruited to a controlled trial of the test product used once daily for 6 months on the face and hands. Clinical assessments were performed at recruitment and following 1, 3, and 6 months of use. Twenty-eight subjects had skin biopsies at baseline and at 6 months of treatment for immunohistochemical assessment of fibrillin. All subjects received the test product for an additional 6 months. Final clinical assessments were performed at the end of this open period, and 27 subjects received the test product for the full 12 months.

In the clinical trial, at 6 months, 43% of subjects on the test product had an improvement in facial wrinkles, whereas only 22% of subjects using the vehicle (product without ingredient complex) had clinical improvement. After 12 months, there was a significant benefit of the test product over that projected for the vehicle. Most interestingly, there was significant deposition of fibrillin-1 in skin treated for 6 months with the test product.

However, the study had several weaknesses. First, there was no statistically significant improvement clinically in facial wrinkles. Also, only 27 subjects received the product for 12 months (when the significant benefit of the test product was seen). Also, more clinical and histological markers could have been evaluated in order to provide even more valuable information about efficacy.

Another recent study evaluated Olay Professional Pro-X: Age Repair Lotion SPF 30, Wrinkle Smoothing Cream, and Deep Wrinkle Treatment (all of the test products in the regimen contained niacinamide, the peptides Pal-KT and Pal-KTTKS, and carnosine.⁴¹ The daytime SPF 30 lotion also contained a broad-spectrum sunscreen