Choosing between the two is very much a matter of convenience and colour preference.
Henna is completely natural. When used on its own, it will make your hair an orange-red, if you are starting from grey or bleached hair, or it will give brown hair a red tint, and black hair a red glow.
But, by adding other natural ingredients, henna can also be used to dye hair brown or black.
Henna has three great benefits: it doesn’t fade as quickly as the other dyes; it helps strengthen and conditions your hair, and it is translucent. It blends over the colour you already have, so there is a certain seamlessness when dying your roots.
Dyeing your hair with henna
Henna should be left in for at least four hours, for a good strong stain, and for a deep red colour (rather than orange) you will want to do this process twice.
The easiest thing to do is apply before going to bed and cover your hair in glad wrap, a plastic bag, or a shower cap, then wash off in the morning.
It does tend to fade a little after a few months, but by then you will likely want to update your roots anyway.
Our hair dyes are without ammonia and are enriched with plant and seed oils to help protect your hair and scalp. They come with a tube of multi-care mask to use after application and in the following weeks to help maintain the dye colour.
In general, permanent hair colour lasts until your hair grows out or you recolour, depending on the hair colour that you use. Hair colour should be refreshed when your roots start to show, which is usually 4-6 weeks.
This does depend on a couple of factors (eg hair dye used, the persons hair etc) but generally speaking hair can be coloured as long as hair fiber is strong and the scalp is in good condition.
If hair is dry, damaged or at risk of breakage, switch to semi-permanent hair colour and start a rigorous conditioning process to restore the hair.
Generally speaking, permanent dye will stay on your hair until the hair grows and roots are exposed. This can take anywhere between four and six weeks, and during this time permanent colour will begin to fade, which is normally around 28 shampoos.