Allergen Cross-Reactor Checker
If you're allergic to one ingredient, you might react to others. Select an allergen to see its known cross-reactors and hidden sources.
Frequently Asked Questions
What is allergen cross-reactivity?
Cross-reactivity occurs when the proteins or chemical structures in one substance are similar to those in another. If you are allergic to one, your immune system may mistake the other for the same allergen and trigger a reaction.
Do I need to avoid all cross-reactors if I'm allergic to the main ingredient?
Not necessarily, but you should be cautious. While some people react to all related compounds (like all formaldehyde releasers), others only react to the specific allergen they tested positive for. Consult your dermatologist for personalized advice.
What is co-sensitization?
Co-sensitization means that people who are allergic to one substance are very likely to also become allergic to another, often because they appear together in nature or in products (like Nickel and Cobalt).
How can I check products for all these different names?
Memorizing all INCI synonyms and cross-reactors is difficult. You can use the AllerNote scanner — once you add your primary allergen to your profile, the AI automatically checks for known synonyms and related compounds.