The Allergy Alert Test represents an important precaution and provides an indication that a reaction could occur if you go on to colour your hair. The Allergy Alert Test simply means checking whether or not you may tolerate the hair colorant of choice on a small, discreet skin area. A positive reaction is a clear signal that your body may have been sensitised to a substance in that product.
You always should do the Allergy Alert Test before you intend to colour your hair even if you have coloured you hair before without any problems. This is because the hair colorant you are planning to use may feature a hair dye you haven’t used before; and most importantly, allergies can develop over time. Also allergies make be caused by other products that you may have used, for example temporary ‘black henna’ tattoos.
Therefore, one should always carry out the Allergy Alert Test for reassurance.
Please be aware that even if an Allergy Alert Test has been carried out you may still experience an allergic reaction when you colour your hair. The Allergy Alert Test is not a guarantee of avoiding future allergic reactions. Please consult a doctor, if you have any doubts.