This year marks the tenth anniversary of Kiehl’s Powerful-Strength Line-Reducing Concentrate, a formula that has attracted lines to the counter while diminishing those visible markers of age from countless patrons: the company sells one bottle per minute, globally. Kiehl’s has sold over three million bottles to date, a Nikean feat for an elixir that took a year to develop and which, the company boasts, contains only nine ingredients.

One of those is pure Vitamin C (L-Ascorbic Acid) at 10.5% concentration. Vitamin C in facial serums is proven to smoothen out lines and wrinkles. It is an antioxidant that helps neutralise damaging free radicals to promote tautness and glow in the skin; supports collagen synthesis; and supplements the vitamin deficit that occurs when UV exposure and the ruthlessness of natural ageing collude in vitiating youth. “The degradation of Ascorbic Acid makes skin more vulnerable to ageing and less able to effectively treat lines, wrinkles and texture issues,” says Dr. Adam Geyer, Kiehl’s consulting dermatologist.

L-Ascorbic Acid is an organic compound that, in its pure form, is a white crystalline powder highly soluble in water. It yellows and becomes less stable when exposed to oxygen and heat. Kiehl’s chemists have stabilised this pure form of Vitamin C with an anhydrous base. When it is applied topically—externally, to a specific region of the body—the formula, attests Dr. Geoff Genesky, Kiehl’s head chemist, offers “efficacy while still remaining gentle on the skin.”

Kiehl’s tested the potency of the Powerful-Strength-Line-Reducing Concentrate over a period of eight weeks on 112 subjects: women aged between 35 and 65 years, across Caucasian, Asian, Hispanic and African American ethnicities. At two weeks, 75% showed significant improvement of fine lines; at four, 83% demonstrated significant improvement in wrinkles. By the eighth week, 86% experienced improvement in elasticity and 90% showed, overall, a more healthy appearance and skin condition.

To complement the serum, Kiehl’s is also offering the Powerful Strength Line-Reducing Eye-Brightening Concentrate. It is engineered to smooth out crow’s feet around the corner of the eyes, a result of the skin losing elasticity. The eye serum is also made to minimise sub-orbital wrinkles and dark circles around the eyes, the thinnest skin on the body strained by constant facial movements. The serum also includes Vitamin C at 10.5%; as well as Haloxyl, a powerhouse ingredient which enhances the skin’s firmness and tonicity; and Lauroyl Lysine, an amino acid derivative that offers a natural, instant blurring effect.