So far I’ve had 2 rinses in my hair, Jazzings and Adore. Out of the two I believe that Jazzings was not harmful at all, in fact, the hairdresser who put in it my hair told me it’s more like a conditioning treatment with some color. As far as the time frame in which the color stays in your hair…well…let’s just say this color rinses out after 4 shampoos, so if you wash your hair a lot or apply products that contain water, beware of that color going fast and all over the place (it’s very messy). As for Adore, I’m really enjoying this rinse that I have in my hair. Some of the ladies who praise this rinse say that it lasts longer and I can agree with that! So far I have had my hair washed 3 times since putting it in and not once have I seen it run down the drain and it’s still as noticeable as ever! I don’t think rinses are harmful; they don’t contain ammonia or peroxide, but some don’t last as long. If you do decide to get a rinse I recommend you use heat with it (if you use heat) to get the most out of the color. HTH.