Allium Cepa (onion bulb extract) is used in topical formulations for its antioxidant, anti-inflammatory, and antimicrobial properties, and is a common component of scar-treatment gels. Evidence for its efficacy in scar improvement is mixed but it is widely included for these purposes.
| Reported effect | How often | Notes |
|---|---|---|
| Mild skin irritation or burning sensation | Uncommon | Transient stinging or redness, especially on broken or sensitive skin. |
| Allergic contact dermatitis | Rare | Sensitization to onion components reported in susceptible individuals. |
| Contact urticaria | Very rare | Immediate hives on contact, mostly in those with onion/garlic allergy. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.
Peer-reviewed papers on this ingredient, via PubMed.