In this session, Cheri Frey, MD, provided an in-depth look at popular cosmeceutical ingredients on the market that all dermatologists should be aware of. Beginning with retinoids, Dr Frey reviewed a new ester of all trans retinoic acid, hydroxypinacolone retinoate, which demonstrates less skin irritation than retinol. Newer combination products containing double-conjugated retinoids and alpha hydroxy acids can improve skin clarity and pore appearance while also having high tolerability. Moving on to antioxidants, Dr Frey discussed flavonoids such as silymarin before diving into the various formulations of vitamin C. L-ascorbic acid is the most biologically active form of vitamin C but is highly unstable as it is oxidized by air and degraded by light and heat. Other more stable forms include magnesium ascorbyl phosphate and tetrahexyldecyl ascorbate. Common additives for vitamin C products include ferulic acid, an antioxidant free-radical scavenger, and vitamin E, a lipophilic antioxidant that works synergistically with vitamin C to provide photoprotection from UV radiation.

Dr Frey briefly reviewed alpha and beta hydroxy acids before finishing off with a discussion of lightening agents. Hydroquinone 2% is no longer available as a cosmeceutical but remains available in pharmaceutical strengths (4% and up). L-cysteamine is a biological antioxidant produced by metabolization of cysteine that inhibits tyrosinase and removes dopaquinone from the melanin synthesis pathway. It is available in a short-contact, wash-off product. Tranexamic acid (TXA) is another lightening agent available in oral or topical form. TXA is a synthetic derivative of lysine that decreases melanogenesis via inhibition of the plasmin/plasminogen pathway and blocks the interaction between melanocytes and keratinocytes. Other lightening agents include ascorbic acid, kojic acid, arbutin, licorice extract, linoleic acid, and aloesin.