Hypoallergenic hair dye is a type of hair coloring that's formulated to be less likely to cause allergic reactions in sensitive users. Allergic reactions are still possible with these options.
About 5 percent of permanent hair dye users experience allergic reactions after using products. The most common reactions are redness and an itchy feeling on the scalp. In rare cases, those symptoms progress and cause systemic reactions in bodily organs. Although allergic reactions usually occur shortly after applying hair dyes, some symptoms can result days or weeks later. Hair dyes that are labeled as being created with all-natural ingredients may be less likely to cause problems than those that contain synthetic chemicals.