Aqua (Water) at a Glance
- The most common first ingredient in skincare formulas
- Acts as the base and solvent for water-soluble ingredients
- Purified before use to remove minerals and impurities
What Is Aqua?
Aqua, listed by its INCI name, is purified water used as the base of most serums, cleansers and moisturisers. It carries and dilutes water-soluble ingredients like glycerin, niacinamide and hyaluronic acid so they can be evenly distributed through a formula.
Being the first ingredient on a label simply means it makes up the largest proportion by weight — it's the canvas the rest of the formula is built on.