Aqua (water) is the most common base ingredient in skincare, serving as a solvent and carrier that dissolves water-soluble ingredients and forms the foundation of emulsions. It has no inherent treatment activity and primarily provides texture and delivery of other components.
| Reported effect | How often | Notes |
|---|---|---|
Irritation or sensitivity | Very rare | Purified water is essentially inert; reactions are not attributable to water itself but to contaminants or accompanying ingredients. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.