Thiamine diphosphate (the active coenzyme form of vitamin B1) is used in some cosmetic formulations as a skin-conditioning agent with antioxidant and metabolic-support properties. It is water-soluble and generally included at low concentrations.
| Reported effect | How often | Notes |
|---|---|---|
| Mild transient skin irritation | Rare | Occasional redness or stinging, typically at higher concentrations or on compromised skin. |
| Contact dermatitis / allergic sensitization | Very rare | Isolated reports; thiamine derivatives have been linked to rare cutaneous hypersensitivity. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.