Glucomannan is prebiotic sugar that combines the simples sugars mannose with glucose. It’s derived from the root of the konjac plant, and is a good source of hydrating polysaccharides for skin.

As a prebiotic, glucomannan serves as a food source for the probiotics that make up each person’s skin microbiome. By supplying food (energy) to your skin’s probiotic strains, prebiotics like glucomannan play an important role in keeping skin’s microbiome balanced, which translates to healthier-looking skin.

In vitro research has shown glucomannan works with a wide range of probiotics to help control the proliferation of acne-causing bacteria on skin. It also has antioxidant ability, which isn’t too surprising given glucomannan comes from a plant.

Glucomannan is also a food ingredient, such as konjac flour. Research has documented its contribution to health benefits, such as weight management and controlling glucose levels in the body.

References for this information:

International Journal of Biological Macromolecules, April 2019, pages 273-281
Food and Science Nutrition, February 2019, pages 788-796
Journal of Zhejiang University Science B, July 2018, pages 505-514
Carbohydrate Polymers, October 2015, pages 398-404
International Journal of Cosmetic Science, April 2010, pages 139-142

Back to Ingredient Dictionary

About the Experts

Paula Begoun is the best-selling author of 20 books about skincare and makeup. She is known worldwide as The Cosmetics Cop and creator of Paula’s Choice Skincare. Paula’s expertise has led to hundreds of appearances on national and international radio, print, and television including:

The Paula's Choice Research Team is dedicated to busting beauty myths and providing expert advice that solves your skincare frustrations so you can have the best skin of your life!