Methylene blue is a phenothiazine dye that acts as a potent antioxidant and mitochondrial-supporting agent, and in dermatology it is also used as a photosensitizer in photodynamic therapy. In skincare research it has been explored for its ability to reduce oxidative stress and support skin cell viability.
| Reported effect | How often | Notes |
|---|---|---|
| Skin discoloration / blue staining | Common | Temporary bluish tint to skin at application site due to the dye's intense color. |
| Localized irritation or contact dermatitis | Uncommon | Redness, itching or stinging may occur in sensitive individuals. |
| Photosensitivity reactions | Uncommon | Increased sensitivity to light, particularly relevant when used in photodynamic applications. |
| Allergic hypersensitivity | Rare | True allergic responses to the dye are infrequently reported. |
| Tissue necrosis at high concentrations | Very rare | Reported mainly with concentrated injectable or medical use, not typical cosmetic formulations. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.