1,3,7-Trimethylxanthine, commonly known as caffeine, is a methylxanthine alkaloid used topically for its antioxidant, anti-inflammatory, and vasoconstrictive properties. It is often included in formulations targeting puffiness, dark under-eye circles, and as a supportive antioxidant.
| Reported effect | How often | Notes |
|---|---|---|
Mild transient skin irritation or redness | Uncommon | Usually mild and resolves after discontinuation; more likely at higher concentrations. |
Skin dryness | Uncommon | May occur with frequent use or in sensitive skin. |
Contact dermatitis / allergic sensitization | Rare | Allergic reactions to topical caffeine are infrequently reported. |
Stinging or tingling sensation | Rare | Typically associated with application near the eye area or on compromised skin. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.