I used to dye my hair regularly for about a decade using L'Oreal Casting Creme Gloss, which is a semi-permanent hair dye. No ammonia, but it does have PPD, which is another ingredient that people react to.
Never had an issue with it and never did a patch test before (I know I should have).
Haven't used it for about 6 years and have been dealing with health issues which have caused quite sensitive skin and mild allergies to things I didn't have issues with before (ie cat hair).
So I've done a couple patch tests this time. 1 on my inner forearm and 1 behind my eye, both for 45 mins as suggested by dye instructions. The inner forearm at 10 mins in had a very minor stinging sensation for about a minute. Behind my ear at about 5 mins had a very minor itching sensation, also for about a minute. Other than that no sensation and change to the skin at all. Will wait to see if any further reaction over the next 48hrs as recommended.
I'm just really unsure as to whether to go ahead now or not. They were such minor reactions, barely there really, that I imagine it'd be fine. But I'm anxious about risking it, especially as I feel I never know how my body's going to react to things these days.
I had wanted to dye it before a haircut later on this week so I could have a fresh new look. My hair colour's looking very dull and have started getting quite a few greys, which I feel self-conscious about as am only in my early 30s. Also just not been feeling good about my appearance recently and sitting in public in front of a mirror under glaring lights for an hour could send me into a spiral, so I wanted to look my best to prevent that. But I don't want to rush into it and then get a terrible dye reaction.
Any advice?