Limonene is a naturally occurring terpene derived from citrus peel oils, used in cosmetics primarily as a fragrance and as a solvent. On exposure to air it oxidizes into hydroperoxides, which are the main sensitizing components.
| Reported effect | How often | Notes |
|---|---|---|
| Allergic contact dermatitis | Common | Oxidized limonene (hydroperoxides) is a recognized contact allergen; reactions more frequent in sensitized individuals. |
| Skin irritation | Uncommon | Can cause redness, stinging or dryness, especially on compromised or sensitive skin. |
| Photosensitivity / phototoxic reaction | Rare | Associated more with citrus oils containing furocoumarins than with pure limonene itself. |
| Respiratory or mucosal irritation | Rare | Reported mainly with high airborne concentrations rather than topical cosmetic use. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.