A skin sensitivity and strand test are a super important first step before any colouring procedure. They help rule out unwanted allergic reactions and also help indicate if your hair is in good enough condition to be bleached or if it is suitable for the colour or toner you wish to use.
We recommend ALWAYS doing these tests before colouring your hair, even if you have used the same products before or if you have used them recently. Allergies can occur at any time and hair colours can look different to the expected results.
Remember, if your hair has not been bleached to a very pale yellow then you will need to do this before using any pastel Super Cool Colours or Shampoos and Conditioners. Use Bleach London Total Bleach or Bleach London Plex Bleach!

If you’re colouring your hair you need to do an allergy test 48 hours beforehand. For a Super Cool Colour or shampoo or conditioner, apply a thin layer of product to a small area inside your elbow using a cotton bud or something similar.
For No Bleach Bleach or any of our Toner Kits, start by mixing one teaspoon of colourant and two teaspoons of developing lotion (using a non-metallic spoon and bowl), then apply a thin layer of the mix to a small area inside your elbow using a cotton bud or something similar.
Leave it for 45 minutes, and avoid contact with clothes while you do. When the time’s up just rinse it off with lukewarm water. If ANY reaction occurs at any point in the next 48 hours do not use the product. It’s worth remembering that sometimes even with an allergy test you may still have a reaction when colouring your hair. This is different for everyone, so if there’s anything you’re unsure about speak to your doctor.

It’s important to always do a strand test before colouring. The colour your hair will end up depends on its current condition and any other products you’ve been using on it, meaning you won’t always see the same results each time. A strand test is the best way of finding out what the end result will look and feel like without risking a seriously bad hair day. The easiest way of doing it is cutting off a small piece of hair, around 1 inch from the root, underneath the crown. Make sure it’s a good example of the overall colour and condition. Secure it somewhere you won’t lose it with sticky tape or cotton. Following the same mixing procedure for the strand test, apply enough mixture of bleach, toner, Super Cool Colour or shampoo and conditioner to cover the strand then leave for the recommended time while you get on with your life.  When the time’s up come back and rinse it thoroughly then let it dry. If the condition feels brittle, gummy or very stretchy then DO NOT bleach or colour your hair.
If you are happy with the colour and condition then you’re all good to go ahead using the instructions included.