I had two allergic reactions to patch tests last year and one earlier this year to different brands of hair colour (home and salon) All I can say in regards to the Flowerology Colour is WOW, FANTASTIC, AMAZING, AND PHEW................ No allergic reaction at all. The colour (Chocolate Brown 5.7) is great, such a deep, warm brown with gorgeous red undertones. It's covered all my greys as well. My hair is so soft as well. I love the fact that the colour is 95% natural and 75% organic. This must be the reason why I haven't had an allergic reaction to it? I will definitely be back for more when I need to re-colour. Thank you, Umberto Giannini :-)