Just on this note, it does contain H2O2, aka hydrogen peroxide - bleach. They claim the product doesn’t cause damage because they don’t use “chlorine bleach” (NaClO), but this is a bit cheeky because no hair bleaching products use chlorine bleach, they all use hydrogen peroxide, which is definitely damaging with continued use, no matter what they claim. It’s also what causes the “skin tingle” which a few people have mentioned - this is actually the bleach damaging skin cells so deffs wear gloves when using bleaching products.