Water is the most common base ingredient in skincare formulations, serving as a solvent for water-soluble actives and as the continuous phase in emulsions. It is considered inert and non-active, providing hydration to the formula rather than direct therapeutic effect.
| Reported effect | How often | Notes |
|---|---|---|
| Irritation or sensitivity | Very rare | Purified water itself is essentially non-irritating; rare reactions relate to impurities or hardness minerals rather than water itself |
| Transepidermal water loss from excess evaporation | Uncommon | Water-heavy products without occlusives may evaporate and contribute to skin dryness in some individuals |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.