Alpha Skin Care's Clarifying Toner has an old school formula…and not in a good, nostalgic way. The first red flag? A high concentration of alcohol (the second ingredient) poses a risk for all skin types (see More Info to learn why). The alcohol is joined by witch hazel and, shortly thereafter, menthol—both of which can incite pro-aging inflammation.
By the way, for those curious, the pH of this formula is too high for the glycolic acid to function as an exfoliant—a surprising shortcoming from a brand that normally gets this critical issue correct.
Long story short: Leave this one off your beauty shopping list and check out our Best Toners list for options that can truly improve skin.
Alcohol helps ingredients penetrate into the skin more effectively, but it does that by breaking down the skin's barrier—destroying the very substances that keep your skin healthy over the long term (Biochimica et Biophysica Acta, 2012 and Journal of Hospital Infection, 2003).
A significant amount of research shows alcohol causes free-radical damage in skin even at low levels (Biochimica et Biophysica Acta, 2012). Small amounts of alcohol on skin cells in lab settings (about 3%, but keep in mind skin-care products contain amounts ranging from 5% to 60% or greater) over the course of two days increased cell death by 26%. It also destroyed the substances in cells that reduce inflammation and defend against free radicals—this process actually causes more free-radical damage. If this weren't bad enough, exposure to alcohol actually causes skin cells to self-destruct (Alcohol, 2002).
Research also shows that these destructive, aging effects on skin cells increased the longer skin was exposed to alcohol; for example, two days of exposure was dramatically more harmful than one day, and that's at only a 3% concentration (Alcohol, 2002). In fact, the effect of inflammation in the skin is cumulative, and repeated exposure to irritants contributes to a weakened skin barrier, slower healing (including of red marks from breakouts), and a dull, uneven complexion (Aging, 2012 & Chemical Immunology and Allergy, 2012).
For more on alcohol's (as in, ethanol, denatured alcohol, and ethyl alcohol) effects on skin, see the Paula's Choice Research Team's Expert Advice article on the topic, Alcohol in Skin Care: The Facts.