Gluconolactone

Gluconolactone is a type of polyhydroxy acid, or PHA. PHAs are supposed to be as effective as AHAs, but less sensitizing.

Gluconolactone is chemically and functionally similar to AHAs (such as glycolic acid). The significant difference between it and AHAs is that gluconolactone has a larger molecular structure, which limits its ability to penetrate the skin, resulting in less potential for sensitizing side-effects. Supposedly, this reduced absorption into the skin does not hamper their effectiveness.

Does that mean gluconolactone is better for your skin than AHAs in the form of glycolic acid or lactic acid? According to an Internet-published class lecture by Dr. Mark G. Rubin, a board-certified dermatologist and assistant clinical professor of dermatology at the University of California, San Diego, research on gluconolactone demonstrated only a “6% decrease in dermal penetration” in comparison to glycol acid, which “isn’t a dramatic improvement.”

Gluconolactone may be slightly less sensitizing for some skin types, but this isn’t the magic bullet for exfoliation some cosmetics companies have been extolling. Polyhydroxy acids can also function as antioxidants and may promote some amount of improvement in skin’s surface strength.