Of the countless different ingredients used in hair and skin care formulas, most are generally safe and effective for the majority of the population. However, many of these ingredients also carry the potential to be sensitizers for some people, producing reactions ranging from mildly unpleasant to truly severe. It is wise to know if you have any specific allergies and to carefully read labels and ask questions of manufacturers to determine whether or not a product is safe for you.
One thing is safe to say, and that is that we are daily exposed to a far greater number of complex substances than our ancestors ever were: medicines both topically applied and ingested, foods treated with many chemicals, processed foods containing many additives, lawn care chemicals, pesticides, cosmetics with long ingredient lists, and chemically-treated clothing and furniture and carpet, just to name a few. The potential for cumulative and synergistic effects is simply staggering when one considers it.
For these reasons, it is nearly impossible to predict when and if a specific ingredient or combination of ingredients in a hair care product may produce a deleterious response. One way to reduce the potential for a sensitization reaction is to reduce your exposure to all of these materials overall. Another thing you can do is to rotate your products, so that exposure is limited and your immune system can “rest.” Restricting the number of ingredients to which you are exposed by choosing products with shorter ingredient lists may be helpful as well. Unfortunately, in the case of allergies, natural is not always better, as many plant and animal-derived products are responsible for allergic reactions. There are companies who strive to create products that are truly hypoallergenic, such as Arbonne, but even still, there may be some who react to one of their ingredients.