Geneviève put me in touch with the dermatologist who developed the formula four years ago. Her name is Hélène. She has her practice in the Paris region, and a small independent laboratory in the provinces where the serum is manufactured.
I asked her directly. Why would one serum, among so many others, make a difference for women over 60, when most products sold to them do nothing?
Her answer lasted an hour. I'll summarize it.
After menopause, facial skin loses up to 30% of its collagen in five years. But the real problem isn't collagen. It's the loss of the ability to reflect light. The skin becomes dull, grey, closed. Wrinkles are just a visible part of the phenomenon. The real reason why our face doesn't look like us anymore at 60 is this gradual extinction of natural radiance.
Most commercial serums are formulated for skin between 30 and 45 years old. The vitamin C they contain, L-ascorbic acid, is unstable. It oxidizes on contact with air, loses its potency in a few weeks, and often burns skin weakened by menopause.
Hélène and her team spent three years stabilizing another form of vitamin C, which they called Stay-C. Three characteristics distinguish it. It remains stable in the bottle. It doesn't burn, even on sensitive or reactive skin. And most importantly, it penetrates better into skin that has lost density after 50 years old.
"This last point is what makes the difference," Hélène told me. "Classic vitamin C remains on the surface of mature skin. Stay-C reaches the layers where it can truly act."