Glossary

Surfactant

Written by Reviewed by the SYNC editorial team Published Last reviewed Editorial standards

Surfactant — a versatile ingredient that lowers the tension between two surfaces, allowing substances like oil, water, and dirt to mix or lift away more easily. In skincare it can act as a cleanser, foaming agent, emulsifier, or wetting agent depending on its structure. Surfactants work because their molecules have one end that is attracted to water and another that is attracted to oil.

Key points

  • Surfactants reduce surface tension, helping otherwise incompatible substances interact.
  • Their dual-natured molecules let them cleanse, foam, emulsify, or improve spreadability.
  • In cleansers they surround oil and debris so it can be rinsed away with water.
  • Surfactants range from very gentle to more stripping, which affects how they are used in formulas.

Frequently asked

What do surfactants do in a cleanser?

They allow oil, dirt, and makeup to bind with water so these can be lifted from the skin and rinsed away.

Are all surfactants harsh on the skin?

No, surfactants vary widely, and many modern cleansers use mild types chosen to clean effectively while minimizing barrier disruption.

Related topics

This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.

Encyclopedia

Further reading

This entry was written and checked against the sources below. They are published by clinical and scientific bodies, they are listed most readable first, and each one opens in a new tab. They are background for the whole entry rather than footnotes to individual sentences.

  1. Soaps and cleansers DermNet NZ Clinical guidance dermnetnz.org
  2. Skin Cleansing without or with Compromise: Soaps and Syndets PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  3. Cleansing Formulations That Respect Skin Barrier Integrity PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  4. Investigation of the Chemical Content and User Comments on Facial Cleansing Products PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  5. Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing PubMed Peer-reviewed (abstract) pubmed.ncbi.nlm.nih.gov
  6. Surfactants have multi-fold effects on skin barrier function PubMed Peer-reviewed (abstract) pubmed.ncbi.nlm.nih.gov

SYNC does not publish medical advice. Nothing here replaces a consultation with a doctor or a pharmacist about your own skin.