Sodium methylparaben is the water-soluble sodium salt of methylparaben, used as a broad-spectrum antimicrobial preservative to prevent the growth of bacteria, yeast, and mold in cosmetic and topical formulations. It is typically used at low concentrations as part of a formulation's preservative system.
| Reported effect | How often | Notes |
|---|---|---|
| Skin irritation | Uncommon | Mild redness or stinging, more likely on sensitive or compromised skin. |
| Allergic contact dermatitis | Rare | Parabens have a relatively low sensitization rate; reactions are more common on already damaged or inflamed skin (the 'paraben paradox'). |
| Contact urticaria | Very rare | Isolated reports of immediate hypersensitivity reactions. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.