Glucomannan description

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 blemish-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.

Glucomannan references

  • 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

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings


Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.


Necessary to improve a formula's texture, stability, or penetration.


Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.


There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.


May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.


We couldn't find this in our ingredient dictionary. We log all missing ingredients and make continuous updates.

Not rated

We have not yet rated this ingredient because we have not had a chance to review the research on it.