How To Tell If Hair Developer Has Expired (3 Easy Ways)

Hair developer is mixed with hair dye to activate it and allow it to penetrate the hair cuticle. But what happens if it’s out of date? Can you still use it? Read on for our tips on how to tell if hair developer has expired.

How To Tell If Hair Developer Has Expired

There are a few symptoms that will indicate if hair developer has expired. These include:

  1. It looks very runny
  2. It has a yellowish color
  3. It no longer has a creamy consistency

How To Tell If Hair Developer Has Expired

All hair products have expiration dates, including shampoos and conditioners we use on a regular basis.

The expiration date on these products is not usually an issue as we tend to finish these before they expire.

When checking if your hair developer has expired, an important thing to be aware of is that you should avoid smelling it too closely.

It might be tempting as it is something we tend to do when we suspect something is out of date.

However, hair developer contains toxic chemicals which can irritate the nose and skin if inhaled at close range.

Having said that, when you open the top of the developer the first thing you may notice is that it smells differently to how it did when you opened it previously. This is the first sign that it may have gone off.

So, what do we do instead?

Check by looking for certain indicators which will tell you that your hair developer is no longer fit for purpose.

  1. If the developer is a liquid developer and it is more liquid than normal, do not use it. This developer is not fit for use.
  2. If you notice a yellowish tinge to your liquid developer, do not use it. This may be a result of exposure to heat.
  3. If the developer is a creamy developer but it no longer has a creamy consistency, do not use it – this is a sign that it has degraded.
  4. If you can see any swelling in the container, avoid use and dispose of it.

Does Unopened Developer Expire? 

DeveloperpProducts don’t tend to carry an expiration date as the manufacturer assumes when you buy it you will use it quite soon after. 

A standard developer can be used within three years if it is closed with the seal intact. As long as the product has not passed its expiration date, it is safe to use. 

It might be worth marking the date you buy the developer on the container so you can keep track of when it needs to be used.

How Long Does Hair Developer Last After Opening?

Once the developer is opened, it will last for 6 months. Again,  mark the date you opened the product onto the product itself so you are very clear on how long you can use it for.

Also Read: Does Dry Shampoo Affect Hair Dye? ( How To Tell)

How Long Does Developer Last After Mixing?

A box of hair dye usually contains the container of hair dye and the container of developer. These need to be mixed.

After mixing, the mixture must be used straight away. After 30 minutes the mixture is no longer suitable for use and one of two things will happen: it won’t work or it can cause damage to the hair.

What Happens If I Use Expired Developer?

How To Tell If Hair Developer Has Expired

It is strongly advised that you do not use a hair developer which has expired nor one which has been opened for over 6 months.

This is because:

The Hair Dye Won’t Work

The hair dye simply won’t work if the developer has expired. This is the least damaging outcome for your hair and a pointless exercise you can avoid by using hair developer that has not expired.

Damaged Hair

Hair developer which has gone out of date can cause damage to your hair leaving your lovely locks brittle and dry which can lead to breakage.

Hair Loss

Don’t forget- hair developer contains chemicals including chemical hydrogen peroxide which can be harmful when it has expired. The hair follicle can be damaged to the point that the result is hair loss.


The skin that makes up your scalp is sensitive and can become easily irritated, in particular when chemicals like hydrogen peroxide are involved.

Chemicals that have passed their expiration date can exacerbate this sensitive skin further, leading to scabbing and itching.


Itching means you will be compelled to scratch that itch. This can damage the skin and produce bacteria which may result in a bacterial infection on your scalp.

In this event, seek advice from a medical professional who should be able to advise you on the matter.

Developers can vary in their ingredients and their volume strength. This means that not all hair or scalps will react in the same way to the different products out there.

Also Read: Too Much Developer In Hair Dye? Easy Ways To Fix

What To Do If You Have Used Expired Hair Developer

If the worst has happened and you have already used the expired hair developer, there are a few things you can try to reduce the extent of the damage:


Even if you are in the middle of dying your hair, and you have realized that the developer you have mixed with the dye has expired, you need to stop the process immediately and get rinsing.

Rinse the entire mixture out of your hair to prevent further damage.

Avoid Heat Tools

Avoid, avoid, avoid! The expired hair developer will possibly have made your hair very dry and brittle. Using heat tools will add to the damage of the weakened hair and possibly cause breakage.

Show Your Hair Some Love

Use nourishing products on your hair to replenish it and restore the lost moisture. Hair masks and deep conditioners are good for this.

How Long Can Developer Stay In Your Hair?

You should closely follow the instructions that come with the product. But as a very general rule of thumb, the mixture of developer and hair dye should not stay on your head for more than 1 hour.

Does Heat Affect Hair Developer?

Yes, it does! Since developer contains the ingredient hydrogen peroxide, it needs to be kept away from direct sunlight. See more on this below.

How To Properly Store Developer 

To keep your hair developer in good condition for use, you need to store it in the correct conditions.

  • Avoid Direct Sunlight

Your hair developer should be stored away from direct sunlight to keep it fit for purpose. A cupboard or a closet would be an ideal place.

  • Correct temperature

Store it somewhere in which the temperature is around 7-20 degrees Celsius.

  • Avoid humidity

Areas like the bathroom can become very humid so avoid leaving the developer out and exposed in your bathroom.

  • Aerated Area

Store the developer in an area that has good airflow in order to help maintain a safe temperature.

To sum up the conditions: the developer should be stored where it is cool and away from moisture and direct sunlight.

How Do You Dispose Of Expired Hair Developer?

How To Tell If Hair Developer Has Expired

A safe way to dispose of hair developer you no longer want is to close it tight, put it into a bag and seal the bag. You can then put this in the garbage. The sealed bag will ensure the smell does not linger.

It is important that you do not pour the developer down the drain or down the toilet as the chemicals could have adverse effects on the sewage system, particularly when mixed with bleach or hair dye. You do not want you and your hair to be responsible for that!

Overall, hair developer is a safe product when used correctly and with due caution. Now that you know the tips to spot expired hair dye and the risks involved to your hair, you can dye your hair safely and keep it healthy and beautiful.

Disclaimer: This site is not intended to provide professional or medical advice. All of the content on is for informational purposes only. All advice should be followed at your own discretion. Ingredients may change at any time so always check the product label before using. Check our full disclaimer policy here.