A substance used to blend two liquids that would not otherwise mix due to differences in their chemical compositions.

Emulsifiers play an important role in many personal lubricant formulas. They work by altering the lubricant’s chemical kinetics, allowing opposing substances to work together – for instance, water and oil – and preventing those substances from separating.

Common emulsifiers include methyl cellulose, cetyl alcohol, methosulfate, and hydroxypropyl cellulose.