Most people don’t think about the expiry date on their hair developer until it’s too late.
But if you want to keep your hair looking its best, it’s important to know when your developer is no longer effective.
In this article, we’ll take a look at how to tell if your hair developer has expired, and what to do if it has.

What is a Hair Developer?
A hair developer, or oxidizing agent, is a chemical used in hair coloring to open the hair cuticle and allow the color to penetrate the hair shaft. It comes in two forms, liquid and powder, and is usually mixed with a colorant to create a hair dye.
When mixed with a colorant, the developer activates the color molecules in the hair dye and helps to deposit the color onto the hair. Developers come in different strengths, or volumes, which determine how light or dark the hair dye will be.
Does Hair Developer Expire? How Long Does Hair Developer Last?
Yes, hair developers do expire. The shelf life of a hair developer depends on the type of developer and how it’s stored, and how often it’s used. Developers that are used infrequently will last longer than those that are used regularly. Powder developers should be used within 6 months of opening.
When it comes to hair developer, there are two types: liquid and powder. Liquid developers have a shelf life of about two years, while powder developers can last up to three years.
However, these are just general guidelines – the actual shelf life of your developer will depend on how you store it.

How to Store Hair Developer
If you want your hair developer to last as long as possible, it’s important to store it properly.
Hair developers should be stored in a cool, dark place, away from direct sunlight or heat.
Powder developers should be kept in their original containers, whereas liquid developers can be transferred to airtight bottles or containers.
It’s also important to make sure that the lid of the container is secure and not leaking, as this can cause the developer to lose its efficacy.
By following these storage guidelines, you can help to prolong the shelf life of your hair developer.
How to Extend the Shelf Life of Your Hair Developer
To extend the shelf life of your hair developer, you can add a preservative to it. One common preservative is glycerin. You can add it yourself, or you can buy a developer that already has glycerin in it.
If you add glycerin to your developer, mix it in well. You don’t want any clumps.
Another way to extend the shelf life of your hair developer is to store it in a cool, dark place. Heat and light can cause the chemicals in the developer to break down over time.
You should also make sure that the lid is tightly closed when you’re not using it. This will keep air from getting in and cause the developer to oxidize.
If you follow these tips, your hair developer should last for several months. However, it’s always best to check the expiration date before using it, just to be safe.
It’s better to err on the side of caution and assume your developer has expired if you’re not sure how long it’s been since you installed it or whether you can recall where you put it.

Signs That Your Hair Developer Has Expired
Here are some signs that your hair developer has gone bad:
- The color has changed: If the color of your developer has changed, it’s no longer effective. The developer that has been exposed to light or heat will often turn yellow or brown.
- The consistency has changed: If the consistency of your developer has changed, it’s no longer effective.
- Liquid developers that have gone bad will often become thick and clumpy.
- Powder developers that have gone bad will often harden or turn to dust.
- It smells different: If your developer has a strange smell, it’s no longer effective. The developer that has gone bad will often have an unpleasant odor.
If you notice any of these signs, throw out your hair developer and buy a new one. It’s not worth taking the risk of using an expired developer, as it could damage your hair.
What to Do With Expired Hair Developer?
If you think your hair developer may have expired, the first thing you should do is perform a patch test.
To do this, mix a small amount of the developer with a colorant, and apply it to a small area of skin, such as your forearm.
If you develop any irritation or swelling, it’s an indication that the developer has expired and you should dispose of it.
Expired hair developer can also be used to remove semi-permanent hair color.
To do this, mix the developer with a color remover, and apply it to your hair. Leave it on for the recommended

Can I Use the Expired Developer?
Expired hair developers may not work as well as they should, so it’s best to avoid using them. If you must use an expired developer, make sure to test it first on a small section of hair to see if it’s still effective.
If the expired developer doesn’t work as well as it should, it could end up damaging your hair. So, it’s generally best to just buy a new one.
Developer Expiration: Things to Keep in Mind
Here are some tips to keep in mind when using a developer:
- Always check the expiration date on your developer before using it; an expired developer may not work as well
- Store it in a cool, dark place: Heat and light can cause the chemicals in the developer to break down over time. So, it’s best to store your developer in a cool, dark place.
- Don’t open it until you’re ready to use it: Once you open the developer, the chemicals start to break down. So, only open it when you’re ready to use it.
- Use it within 6 months of opening: Once you open the developer, you should use it within 6 months. After that, the chemicals will have broken down too much and it won’t work as well.
- Don’t freeze it: Freezing can also damage the chemicals in the developer. So, don’t store it in the freezer.
Following these suggestions will assist you in keeping your hair developer from expiring.

Conclusion
That is all there is to know about hair developer and when it expires. Hair developer does expire, so be aware of the warning signals. If you believe your hair developer has expired, test it on a tiny sample of hair first.
Keep in mind to double-check the expiration date before using it, and store it in a cool, dark location. If you follow these instructions, your hair developer should last a long time.
It’s also usually best to just purchase a new one rather than risk causing damage to your hair with an expired developer.
Following the recommendations for safe storage can also help to keep your hair developer from going rancid.