Patch test hair dye? is this something that everyone should be doing?

Dyeing your hair is a great way to achieve a new style, or keep up with the latest trends. It can completely transform your look and is a perfect way to express yourself.

But before you take the plunge, there’s one important step you need to take: the patch test.

A patch test will help you determine if you’re allergic to the hair dye. It’s a simple test that only takes a few minutes, and it could save you a lot of discomfort and irritation.

Patch tests can often be carried out at home, but if you have the pleasure of an experienced stylist working on your hair, you will need to visit their salon before your appointment; as this is a requirement by the company.

Patch tests are important because they can help you avoid a potentially serious allergic reaction.

In this article, we’ll show you how to do a patch test for hair dye and what to do if you’re booked in with a professional.



What is a Patch Test?

A patch test is a way to test for an allergic reaction to a new hair dye. It is usually done by mixing a small amount of hair dye and rubbing it on an area of skin, typically behind the ear.

The patch test will show results within 48 hours of application so you can see if you having any reaction to the hair dye. This usually comes in the form of redness or swelling.

The reaction is caused by certain chemicals and other ingredients within the hair dye not agreeing with your body, the same as any other allergic reaction a person can experience.

They are often used for other products in addition to hair dye such as soaps and new cosmetics.

If you’re visiting a salon, the stylist will apply the same hair dye that they intend to use at your appointment to ensure the chemicals are safe to use.


Why do I need to do a patch test?

A patch test can save you from having an allergic reaction to the hair dye being used.

As we mentioned above, a person can have a reaction to certain chemicals in the dye. On occasion, these reactions can be severe, and much more than just swelling and redness.

Doing a patch test will ensure the risk is minimised as you are only applying a small amount of dye. If you were to dye your hair without carrying out a test, the reaction could be amplified due to your whole head being covered.


Is a hair dye allergy test necessary?

If you’re booked in with a salon, a hair dye allergy test (also known as a ‘patch test’) is a compulsory requirement.

The salon is required to perform a patch test on clients before applying hair dye, so you will need to book an appointment at least 48 hours before you are due for application.

If you are dying your hair at home, it is also vital that you perform a patch test. Not only can it test to see if your body is having any adverse effects to the hair dye, but it can also prevent you from having extreme allergic reactions.


How long does a hair dye patch test take?

It is recommended to leave the hair dye on your skin for at least 48 hours after your patch test to ensure you don’t have an allergic reaction.

If you don’t have any signs of a reaction within this time, then it is typically safe to go ahead with the application.

When visiting a salon, you will need to book a patch test at least 48 hours before your colouring appointment. The stylist will also ask you a few questions to make sure that it is safe to continue applying the dye.


Where to do a patch test

A patch test should be done somewhere your body grows little to no hair. Typically a patch test is done behind the ear as this produces the best results, but can also be done in places such as your wrist, or inner elbow.


How to remove hair dye after a patch test

After your 48-hour window of applying a small application of hair dye to your skin, you can safely wash the dye off.

There is no specific way that you need to remove the dye, though alcohol-based products have the best chance of removing it. Of course, only use ones that are safe for your skin and be careful not to rub too hard and graze the skin.


How to do a patch test for hair dye

To do a patch test for hair dye, mix a small amount of the dye in a bowl. Apply the small amount of the mixture to a clean area of skin, such as the back of your ear.

You will need to monitor the area for the next 48 hours. If you do not experience any redness, itching, or swelling, you are not allergic to the dye and it is safe to use. Here’s a breakdown of how to do a patch test step by step.

Step 1: Apply the hair dye

The first step in performing a patch test is to apply the hair dye to your skin. You will need to mix a small amount of hair dye (make sure you don’t do the whole box as it won’t last until you’re ready to apply it all over!) onto a soft substance such as a cotton bud.

You will then need to rub the cotton bud onto a small area of skin; the best place for application is behind the ear.

Step 2: Wait and monitor

Once you have applied the small amount of dye, you will need to wait at least 48 hours to check if you have any sort of allergic reaction.

This is typically displayed in the form of swelling, redness, or itchiness.

The dye will need to be kept on the skin and not washed or rubbed around in the 48-hour window.

If you do have an allergic reaction to the hair dye you should wash it off immediately and inform your doctor.

If you are booked in with a stylist, you will also need to contact the salon to let them know you have had a reaction.

Step 3: Wash if off

Once your patch test is complete you are safe to wash the dye off your skin.

If you haven’t had an allergic reaction within this time it is likely that the hair dye is safe to use and you can continue with the application.


In case you prefer a more visual guide, Garnier UK has a great short clip on YouTube showing the process in action.

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Can you shower after a patch test?

You can shower and wash off the hair dye used in your patch test after 48 hours have passed since it has been applied.

This will give your body ample time to react to the dye.


To Wrap Up

As you can see, performing a patch test before colouring your hair is essential. It can save you any irritation, and in some cases, severe allergic reactions. You will need to carry out this process 48 hours before your plan to dye your hair. If you’re booked in with a professional stylist, you will need to make sure you visit their salon at least 48 hours prior to your appointment for this test.