Sodium metabisulphite is an inorganic sulfite salt used in cosmetic and pharmaceutical formulations primarily as an antioxidant and preservative to prevent oxidation and discoloration of sensitive ingredients. It is typically present at low concentrations as a formulation stabilizer rather than as a therapeutic active.
| Reported effect | How often | Notes |
|---|---|---|
| Contact irritation (stinging, redness) | Uncommon | Mild local irritation can occur, particularly on compromised or sensitive skin. |
| Allergic contact dermatitis | Uncommon | Sulfites are recognized contact allergens and can cause delayed hypersensitivity reactions in sensitized individuals. |
| Urticaria or hypersensitivity reactions | Rare | Sulfite-sensitive individuals may develop hives or immediate-type reactions. |
| Respiratory/anaphylactic reactions | Very rare | Severe systemic sulfite sensitivity reactions are documented mainly with ingestion/inhalation but rarely reported with topical exposure. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.