Bentonite at a glance

  • Clay derived from volcanic ash (which is purified before becoming a cosmetic ingredient)
  • Most famously used as an oil-absorbing agent in facial masks
  • Also functions as a thickener, emulsion stabiliser, and opacifying agent in cosmetic formulas
  • Helpful for oily skin but can be drying for other skin types (when used in high amounts)

Bentonite description

Bentonite is a type of natural clay that is most famously used as an oil-absorbing agent in facial masks and other cosmetics. While its absorbent properties are helpful for those with oily skin, it can be drying for other skin types (especially when used in very high amounts). To overcome this, some formulators pair bentonite with hydrating/soothing ingredients. These work to limit the absorbency of bentonite while still allowing skin to benefit without becoming dried out. Other reported functions of bentonite in cosmetics include bulking agent/thickener, emulsion stabiliser, opacifying agent, and suspending agent. Raw bentonite is derived from the alteration of volcanic ash and is mainly composed of the minerals montmorillonite and illite. It undergoes a purification process before being sold as a cosmetic ingredient and has a long history of safe use. Further backing bentonite’s safety, it is generally recognized as safe (also known as GRAS status) by the US FDA as a direct food additive.

Bentonite references

  • BMC Chemistry, September 2021, pages 1-11
  • SN Applied Sciences, May 2019, pages 1-13
  • Journal of pharmaceutical investigation, May 2016, pages 363–375
  • International Journal of Toxicology, March 2003, pages 37-102

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.


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Not rated

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