Sun-In was one of these products that you asked every friend or relative that travelled to the US back in the 80s or early 90s to bring. The spray gave a sun-kissed look to the hair without the need of staying in the beach for hours (and frying your skin). I was 11 or 12 when my mother brought it from a trip to Orlando. You needed to spray it sparingly and then blow dry, so the heat would activate the bleaching effect.
I never cared to learn what was in the formula, but researching for the post, found out the obvious: it’s peroxide. This means that it contained a recipe to damage your hair after a while… Anyway, who cares about that when you are a tween?
I really thought that Sun In was resting in peace along with other 80s fads (that dirty blonde and bad perm look…) since there are so many modern techniques to lighten your colour. Surprise! It is still available and you can purchase at Amazon, now with improved formulas, containing lemon extract and nourishing oils. But I’m sure the fun factor is hidden somewhere in 1990!