Hydroxyethylpiperazine Ethane Sulfonic Acid



No known benefits

Hydroxyethylpiperazine Ethane Sulfonic Acid description

Also known by the acronym HEPES, hydroxyethylpiperazine ethane sulfonic acid is a buffering ingredient typically used to establish a neutral pH in water-based solutions. There’s research indicating it can generate free radical damage in the presence of oxygen, which means it could be a problem when used in skincare products. Even though research on how this directly impacts skin hasn’t been done, it’s an ingredient we advise avoiding in cosmetic products. There are definitely other buffering agents that are less problematic and have had safe concentration protocols established.

Hydroxyethylpiperazine Ethane Sulfonic Acid references

  • Journal of Inorganic Biochemistry, August 2005, pages 1,653-1,660 and November 2004, issue 11, pages 1696-1702

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.