Ingredient dictionary
Aqua
Also listed as: Water
Aqua is purified water, used as the main base of most skincare, haircare and makeup. It dissolves other ingredients and carries the product's texture. Checked against our library November 6, 2026.
What Aqua does
- Dissolves water-soluble ingredients
- Makes up most of the formula
- Helps spread the product evenly
Aqua is water that has been purified before use, usually through filtering and treatment steps that remove minerals and microbes. Because it is inexpensive, easy to source and blends with almost everything, it is the most common ingredient in beauty products.
Water is the carrier that lets other ingredients spread evenly across skin or hair. It feels light and cool as it evaporates, which is why lotions and cleansers feel fresh. Because water can support microbes, formulas that contain it also include preservatives.
Good for
Suits nearly all skin and hair types, since it is the base of most formulas and is well tolerated by most people.
Frequently asked questions
Is water in skincare bad for my skin?
No. Water is a well-established, widely used base in skincare. It does not harm skin on its own. Most people tolerate it well, and it is the main ingredient in many gentle cleansers and moisturizers. Any irritation usually comes from other ingredients in the formula.
Why does water need preservatives?
Water can support the growth of bacteria, yeast and mold once it is in a product. Preservatives help keep the formula stable and safe to use over time. This is why most water-based products list a preservative.