Does Hair Developer Expire? How to Know

Does hair developer expire

So you decide you want to change up your look and dye your hair. You reach into the back of your bathroom cabinet for a box of hair dye and that bottle of hair developer that you bought forever ago. Before you get to work on your new look you think to yourself, “Does hair developer expire?” In short, yes. Hair developer can expire, and it is best to get a new bottle before you risk damage to your ‘do.

Is Hair Developer the Same as Hair Color?

Hair developer, or activator, is a creamy product containing hydrogen peroxide that is mixed with dye or bleach to activate the hair color and allow it to penetrate the hair cuticles, essentially making your color permanent. Without it, your hair color would be ineffective.

When buying boxed hair dye, there are typically 2 bottles in the box: a bottle of the dye and a bottle of developer. Alternatively, hair developer can be bought separately, and in different volumes or strengths depending on your desired results.

Different volumes of hair developer depend on their oxidizing potential. You can find developers with volume levels of 10, 20, 30, or 40.

10 Volume Developer

10 volume developer contains 3% hydrogen peroxide and is best used when darkening your hair by 1 level or to tint hair that is already the same lightness level.  It should not be used to lighten your hair.

20 Volume Developer

If you are lifting your hair by 1-2 levels, you should use 20 volume developer. This is the most common strength of developer and is typically used for permanent dye as well as temporary color.

30 Volume Developer

This strength of developer can lighten your hair up to 3 levels. It can also be used to completely cover gray hair.

40 Volume Developer

40 Volume Developer is the least common force of developer and is used only for lightning. It can lighten hair up to 8 levels. However, this strength of developer is for professional and salon use only and should not be used at home.

Does Hair Developer Expire – How to Tell When Hair Developer Is Bad

Your hair developer may not come with an expiration date clearly labeled on the bottle, but there are a few practices to identify when it is time to toss your bottle. These include:

The 6 Month Rule

How long does hair developer last after opening? An easy way to make sure you’re not using expired product is to throw it out after it has been opened for 6 months. Write the date on your bottle after opening to keep track of time passed.

Smell It

The age-old rule “when in doubt, throw it out,” applies to more than just food. If your developer smells strange, or different from when you originally purchased it, it may be time to toss it. Warning: Be sure not to get too close to the product when smelling, as there are still active chemicals in it that could irritate your nose and skin. The safest way to smell your developer is to notice if it discharges a strange smell when opening the bottle. If you do not notice a change in smell, try one of the following strategies to determine whether your bottle is bad.


Developer is typically creamy and smooth. If your developer seems to be more liquid, or the texture is inconsistent, it has most likely degraded and gone bad.


If your developer has taken on more of a yellowish tint, it has probably expired. Hair developer can go bad in the heat, and a yellow color can indicate it was exposed to the sun. Since developer contains active hydrogen peroxide, it needs to be kept out of direct sunlight. You should store your developer somewhere room temperature and away from moisture and sunlight, such as a closet or cabinet.

Swelling to Packaging

If your bottle of developer has swelling or has taken on an unnatural shape, it is best to dispose of it.

Is it Mixed?

When purchasing a box of hair dye, the box typically contains a container of dye and a container of developer instructed to be mixed together. Once combined, the mixture is to be used immediately. After 30 minutes, the mixture is no longer good and can be ineffective or cause damage to your hair. Once applied, the mixture should not stay on your head for more than an hour.

Does Unopened Hair Developer Expire?

When unopened, hair developer has a longer lifespan. If unopened, it is best to use your hair developer within 3 years. After this time, the developer can cause a risk to your hair health. Even unopened, your developer should still be stored away from sunlight and moisture, as the heat and moisture can damage it or reduce the effectiveness of the product. So it is best to keep it away from your bathroom window or sink when storing.

Why Does My Developer Not Have An Expiration Date?

Hair developer, like many other hair products, is intended for use soon after purchasing. For this reason, manufacturers often do not print expiration dates on products like developer, dye, hairspray, shampoo, and conditioner because they assume the product will be used before expiring. For this reason, the FDA does not require manufacturers to provide expiration dates on many of their hair products.

As a general rule of thumb, opened products usually do not have a shelf life of more than 6 months. So next time your favorite hair dye has a 2-for-1 deal, think twice before you make a mass purchase, as your product won’t be good forever.

Can You Use Expired Hair Developer?

You should not use expired hair developer. Using expired developer can result in many consequences to your hair and scalp. Some of these include:

1. Your Hair Product Won’t Work

As mentioned before, permanent hair color is the result of the dye and developer working together. Using expired developer may cause your desired color not to stay, or turn out different than expected. It’s better to avoid the expired product and save yourself a possible color nightmare.

2. Damaged Hair

Using your developer past the recommended time frame can damage and even burn your hair, leaving your locks looking dry and brittle. This damage often leads to breakage and split ends as well.

3. Itchiness

Your scalp is made up of very sensitive skin, which is why many people consider themselves tender-headed. Irritation to sensitive skin, especially when chemicals like peroxide are involved, can lead to itching and scabbing.

4. Bacterial Infections

Another side effect of using expired hair developer is a bacterial infection. After itching away at your scalp from the use of expired chemicals, damaged skin can start producing bacteria from a combination of irritants, leading to an infection on your head. If this happens, call your doctor or dermatologist, who may be able to prescribe you medicine to fix the problem.

5. Loss of Hair

Using an expired developer may also result in loss of hair. The expired developer could damage the hair follicle to the point of hair loss. This is a more extreme side effect and one that you do not want to experience.

What to Do if You Use Expired Hair Developer

If you have already used your bad developer, there are a couple of things you can do for damage control.

1. Rinse Immediately

If you are in the middle of your dye job, it is best to rinse out the mixture immediately to limit the amount of possible damage that could be done to your hair and scalp

2. Avoid Heat Tools

If you’ve already used the bad developer for your dye job, it is probably wise to avoid using heat tools like a curler or flat iron for a little while to avoid further damage. Since expired developer can cause dry and brittle hair, heat damage will only worsen your hair’s texture. If you absolutely must use a heating tool, apply heat protectant on your hair first.

3. Use Reparative Products

Products such as hair masks or deep conditioners may help repair damaged or dry hair. Hair masks are usually a cream product that you apply to your hair for an extended amount of time, depending on the instructions of the specific manufacturer. They can be used to repair damage and restore moisture to your hair.

How to Dispose of Expired Hair Developer

The safest way to dispose of your old hair developer is to close it tightly, seal it in a bag, and throw it in your normal garbage can. It is important to put it in a sealed bag as it may have a strong smell, and you don’t want that to linger in your bathroom. Do not pour it down the drain or flush it, as the chemicals could disrupt the sewage system, especially when mixed with bleach or hair dye.


While hair developer is an overall safe product to put in your hair when used correctly, it is always important to take precautions, especially when you think it may be expired. If you follow these tips and know the risks of using a bad developer, you’ll keep your hair looking healthy and amazing after every dye job!

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