The Larousse Dictionary defines the term hypoallergenic as follows:
“A substance that causes few allergic reactions.”
We are therefore talking about substances that reduce the risk of allergies or that cause few allergies. It does not mean materials that are completely anti-allergy.
The thing is, allergies vary widely from one person to another. It would therefore be too hard to identify a product as being anti-allergy.
And since the term hypoallergenic or hypoallergen is not regulated, you can rest assured that unfortunately, it will be used anyway.
Therefore, if you reacted to some products in the past, it is better to identify them correctly and then to avoid them, as the term hypoallergenic is not a term that guarantees that the product will be suitable for you and your allergies.
The synonyms you may find written on products are hypo-allergenic, hypoallergenic, and hypoallergen.
For anti-allergy products, the term anti-allergy (which does not cause allergy) is generally used or these other terms: anti-allergic, antiallergic, antiallergenic, or anti-allergenic.