In our reference data, Alpha-Isomethyl Ionone is an EU-declared allergen.
Alpha-Isomethyl Ionone is a synthetic fragrance compound with a sweet, violet-like floral scent used to impart or enhance aroma in cosmetic and skincare formulations. It has no therapeutic skin benefit and serves purely an olfactory/sensory role.
| Reported effect | How often | Notes |
|---|---|---|
Allergic contact dermatitis (skin sensitization) | Uncommon | Recognized as one of the 26 EU-regulated fragrance allergens requiring label declaration; can cause delayed eczematous reactions in sensitized individuals. |
Skin irritation or redness | Uncommon | Mild irritation possible, particularly on compromised or sensitive skin. |
Positive patch-test reactions | Rare | Documented in fragrance-allergic patients during diagnostic patch testing, though at relatively low rates compared with other fragrance allergens. |
Photosensitivity or photoallergic reaction | Very rare | Rarely reported; not considered a significant phototoxic agent. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.