If you are thinking on the level of these chemicals causing any changes to the skin's DNA, then I don't think that question can be answered with any positivity. You would have to investigate to see if there have been any good studies done on this.
If you are asking in terms of will prolonged use of bleaching and depilatories products make a hair problem worse, the answer is they could very well make a hair problem worse. Anything that irritates the skin over time can cause hair to arouse and grow sturdier. This is nature's way of protecting the skin by providing a cushion of hair.
Dee
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Dee Fahey, R.N., C.T.
Licensed by the State Medical Board of Ohio for Nursing license and Cosmetic Therapy/Electrolysis license