I've been using Boots henna and horsechestnut shampoo and conditioner for some time and am now wanting to dye my hair a permenant colour. Can I do this safely as I've read that you shouldn't use a chemical dye (like Loreal Feria) after dying your hair with henna. Is the same true if you've used a shampoo containing henna?
I've been using Boots henna and horsechestnut shampoo and conditioner for some time and am now wanting to dye my hair a permenant colour. Can I do this safely as I've read that you shouldn't use a chemical dye (like Loreal Feria) after dying your hair with henna. Is the same true if you've used a shampoo containing henna?

Edit: The shampoo states that it enhances the colour and shine of red and brown hair