Assessing the Efficacy of Anti-Aging Cosmeceuticals

By Coyle S. Connolly, DO

Despite the extensive and unparalleled knowledge of cutaneous physiology within the dermatology field, many clinicians lack confidence to provide specific recommendations to patients regarding antiaging skin care. Instead, they may emphasize the need for certain categories of skin care products, such as a moisturizing sunscreen in the morning and a reparative moisturizer each evening, or even recommend only broad ingredient classes, such as antioxidants or hydroxy-acids. This had been understandable in the past, when “cosmeceutical” formulations often were not well studied in human subjects with photodamage or results of studies were not published in peer-reviewed publications. Plus, the FDA does not oversee or approve these products,^1-3 leading to confusion among patients as well as dermatologists. ⁴ Nonetheless, some cosmeceutical formulations provide efficacy and are suitable for use alone or in combination with other antiaging interventions.^1,4 Given the number of products now marketed to patients, clinicians should focus on educating patients about wise product selection rather than permit them to blindly choose potentially expensive products that, despite containing possibly effective ingredients, may not provide their proposed effects.¹ In recent years, more reliable studies of finished formulations have appeared in the peer-reviewed literature, enabling clinicians to make better-informed, specific product recommendations to their patients.

Patient Concerns

Clinical signs of photodamage include wrinkling, pigmentary changes, roughness, laxity and telangiectasia; Various histological and cytological changes induced by acute or chronic UV exposure are considered primary drivers of these skin signs of aging.5 One model conceptualizes the cumulative nature of photodamage based on three main categories:

Type A includes color changes, including hyperpigmentation, lentigines, and telangiectases.
Type B includes wrinkling, including both deep and fine rhytides, texture changes, large pores, and reduced skin laxity.
Type C includes actinic keratoses and cutaneous malignancies.⁶

While procedures such as microdermabrasion, chemical peels, injectables, and energybased treatments all may provide some degree of improvement of these signs of photodamage— and are increasingly popular with patients—anti-aging skin care remains the most accessible and popular form of “treatment” for photodamage. The prestige antiaging skin care market, comprised largely of so-called “cosmeceuticals,” is estimated at more that $1.2 billion in the US, and a survey of 6,403 consumers showed that anti-aging is the key driver of facial skin care product purchases. ⁷ This consumer spending is in addition to any purchases of mass-market or storebrand skin care products that increasingly tout anti-aging effects. Spending so much on skin care products, women and men want to know that their investment is worthwhile, and they expect dermatology practices to guide them.

Cosmeceuticals in Context

The term “cosmeceuticals,” coined to describe a pharmaceutical-quality cosmetic, is not used or recognized by FDA or any other regulatory agency. As far as the FDA is concerned, products popularly called cosmeceuticals are properly classified as “cosmetics.” A publication clarifies, “Traditional cosmeceuticals involve the topical application of biologically active ingredients that affect the skin barrier and overall skin health. … In the United States, cosmeceuticals are sold as cosmetics, making marketing, packaging, and aesthetic appeal important considerations.”³ Because FDA classifies any substance that alters the structure or function of the skin as a drug, cosmeceutical marketers carefully describe the “benefits” of their products. Were they to demonstrate that a product modified the structure or function of the skin, they would have to seek approval to market the formulation as a drug, requiring a new drug application and the extensive and expensive trials that process entails. Instead, cosmeceutical marketers emphasize a formulation’s ability to improve skin appearance.³

To market a cosmetic, one need only show that the product or formulation is safe for human use. Marketers need not conduct any trials of a formulation, though many perform small-scale studies in humans. Unlike drug trials, these studies often are not blinded or controlled, and they typically involve only small cohorts. The emphasis it may seem is on acquiring compelling images or case reports to support marketing and advertisements. This should not suggest, however, a dearth of reliable scientific evidence for cosmeceuticals.

A substantial body of evidence exists to suggest skin enhancing benefits for a wide variety of popular cosmeceutical ingredients, including vitamin C (ascorbic acid), retinol, hydroxy acids, and numerous botanical extracts. However, these studies are often performed in vitro on cultured fibroblasts or in mice. In vivo human data is less abundant. Plus, studies typically involve direct topical application of pure agents. In everyday use, the optimal concentration of active agent, the impact of the formulation, and any beneficial or detrimental effects of inactive ingredients cannot be overlooked. For example, one in vivo comparative study found that the antioxidant capacity of ascorbic acid is optimized in an aqueous vehicle while a derivative, ascorbyl tetra-isopalmitate, had greater antioxidant potential in a lipid-based formulation.⁸

Clearly it is not enough to simply show in the laboratory that a particular agent can confer rejuvenating benefits. Proper steps must be taken during product formulation to preserve the potency and optimize the efficacy of the ingredient. Furthermore, to increase clinicians’ confidence in prescribing such agents, in vivo evidence of the efficacy of a finished product is desired. In response to clinical need, a growing body of reliable in vivo evidence is accumulating and being published for some products.

Evaluating Evidence

In order to make meaningful anti-aging skin care recommendations, clinicians may need to do some legwork. For practice-dispensed formulations, company representatives should be able to provide a summary of all available data, including any peer-reviewed publications of their finished formulation.

Data can also be found through a search of the published data, which is evolving rapidly. For example, a positive 12-week, single-arm, open-label study investigating the efficacy and tolerability of C8 Peptide Intensive Treatment (Kinerase®, Valeant) facial serum has recently been published.⁹ Thirty-four female subjects aged 40-60 with Fitzpatrick classification I-IV with early to advanced photodamage at baseline completed the study. Subjects could use no other anti-aging, anti-wrinkle, skin lightening or other topical or systemic product known to affect skin aging or dyschromia at least 30 days prior to study entry and through the study period. They were instructed to use a gentle cleansing wash (provided to them) prior to applying facial serum and a provided moisturizer lotion with SPF 15, each morning. Clinical assessments and patient selfassessments were made at baseline and weeks weeks 4, 8 and 12. Resiliency was measured with a cutometer; digital photography was used to document visible changes in other parameters.

As early as week 4, there were significant improvements in all parameters and skin conditions (p≤0.05), and by week 12 there was an 18 percent improvement in overall appearance (p≤0.05). Statistically significant improvements in wrinkling, pigmentation, elasticity, and other parameters were also identified. Fine lines and coarse winkles improved by 27 percent and 15 percent, respectively. Uneven pigmentation improved 10 percent, firmness/elasticity 11 percent, tone/resiliency 18 percent, skin radiance 21 percent, tone 16 percent, and tactile roughness/ smoothness 47 percent.

Subjects reported a 43 percent improvement in overall facial skin appearance and 24 percent reduction in mean scores for facial lines and wrinkles at week 12. Patient reports also indicated improvements in overall skin tone, firmness, dryness, appearance of pores, appearance of brown spots/facial discoloration, skin radiance and texture (37 percent, 35 percent, 35 percent, 28 percent, 24 percent, 39 percent, 38 percent, respectively, all p≤0.05). Subjects reported a 71 percent reduction in erythema and 94 percent reduction in skin dryness (both p≤0.05) at the study’s conclusion.

Sharing Expertise

Much of dermatology practice centers on educating patients and encouraging them to take an active role in the prevention and management of skin conditions like acne, psoriasis, atopic dermatitis, and rosacea. Management of photodamage is no different. In addition to providing instruction on proper use of sunscreen and UV avoidance strategies and encouraging regular at-home and inoffice skin exams, dermatology care providers can also provide specific advice for the topical management of the signs of photodamage. Keeping abreast of the literature allows clinicians to understand how cosmeceutical formulations perform in practice and supports meaning product recommendation.

Cosmetic Skin Care in Dermatology Practices

According to recent data from the American Academy of Dermatology Association (AADA), dermatologists on average dedicate about eight percent of their patient care time to cosmetic dermatology, while physician extenders in these same practices spend 10 percent of their time in cosmetic dermatology, on average. About a quarter of all dermatology practices employ an aesthetician. Of these, many practices employ more than one aesthetician. Clearly, dermatology practices dispense a good deal of cosmetic skin care advice—and often skin care products. It is not known for certain what percentage of dermatology practices dispense skin care products, but it is clear that many do.

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