Does Hair Dye Expire? Learn How Long Hair Dye Last After Opening It

Our hair color may not last forever, but our desire to maintain our preferred hair color often does.

Society has a seemingly double standard for men and women when it comes to going gray (a graying man is a “pepper pot” or “silver fox,” whereas a graying woman all too often gets treated like Mrs. Havishamn-esque hags).

Either way, few of us would choose to “go gray” if we could keep our current hair color, which is why hair dye flourishes.

Plus, if you consider those who choose to dye their hair, not to cover up gray, but as a form of self-expression, it’s no small wonder why the beauty industry (and the hair dyes it sells) is expected to top $40 billion within the next two years.

In fact, according to the national average, you can expect to pay approximately $100 per month for professional hair dying services.

Although, whatever the reason you dye your hair, and however much you may spend on it, you definitely don’t want to spend all that time and money only to see it go bad, which begs the question – does hair dye expire?

If so, how soon? How can you determine if hair dye has expired? What can you do to keep it in the best condition for as long as possible?

How Long Does Hair Dye Last Before It Expires?

Does hair dye expire? Unopened hair dye can last up to three years. However, once you open it, it will likely only stay good for one to two years at most.

Expired hair dye will often show signs going bad, including packaging damage, foul orders, discoloration, oxidation, and a breakdown of the dye’s chemical makeup (i.e., noticeable separation).

Hair coloring treatments can be damaging to the hair shaft, even when the product isn’t expired. Consequently, we don’t recommend using expired hair dyes due to the potential side effects, including hair loss.

Why Does Hair Dye Go Bad?

There are several reasons that hair dye goes bad, not the least of which being that once you open the bottle, moisture can seep in and cause problems.

While moisture may not spoil the hair dye, it can lead to many problems, including oxidation.

The more water that seeps in, the worse the oxidation gets, and the faster that expiration clock ticks away until time’s up and you have a watery spoiled mess.

This problem is worsened by the fact that hair dyes typically contain peroxide, which reacts with oxygen and, in the process, spoils the dye.

Then there’s the issue of sunlight. There are reasons why you shouldn’t expose freshly-dyed hair to sunlight, but even before you make it that far, you need to ensure that the dye stays good long enough to use it. Prematurely exposing it to the sun’s rays and UV radiation can cause it to spoil. 

Part of this has to do with temperature. If the hair dye starts to heat up even while it’s in the box, it will quickly start to degrade as the heat separates the ingredients.

Moisture, sunlight, and oxygen aren’t the only bad things that can arise from cracking the seal and exposing your hair dye to the elements.

Certain microorganisms can thrive in the ammonia that is contained in hair dye. If you think hair dye separating and spoiling sounds bad, wait until it becomes a bacterial cesspool.

What breeds bacterial infestations faster than standing fluid plus sunlight? The combination of both plus some heat is enough to transform your hair dye container into a petri dish.

How to Tell If Hair Dye Has Expired?

When buying conditioner and shampoo, you’ll want to be on the lookout for indications on the bottle that mark how long it will remain good, for example, 3M for 3 months and 12M for 12 months.

You may think that you’ll be able to simply check the date on your hair dye in the same way – but you’d be wrong.

While some hair dyes do indicate an expiration date, others lack this kind of identification. Thankfully, there are several signs that hair dye has gone bad. Some of the most evident and notable are discussed below.

1. Foul Odor

This is probably the most obvious indication that you shouldn’t use any beauty product. It’s fair to say that if something reeks, it probably isn’t something you should be rubbing into your hair.

Expired hair dye will often smell foul as a result of the product’s chemical makeup breaking down.

2. Changes in the Packaging

One of the most important shopping adages is to leave packages that seem damaged alone, especially if they contain something perishable.

Organic and chemical-based products can be finicky, and all it takes is the slightest dent or rip in the packaging to expose them to the elements, which, as demonstrated above, could mean exposing them to a whole world of trouble.

If you see that the package is dented, lumpy, swollen, or otherwise out of the ordinary, you’re better off tossing it.

One of the most obvious examples of this and another sign that your hair dye has seen better days is if it is leaking.

The packaging should not be so flimsy as to allow hair dye to seep out, and it shouldn’t be that watery in the first place. If it is starting to leak out, it’s ready to be thrown out.

3. Discoloration

Strange discolorations around the cap are another sign that your hair dye isn’t in good shape. Whatever hair color it may be, it should not leave a discolored ring around your container.

Red, yellow, and orange are all common colors that can indicate discoloration when not the primary color of the dye.

4. Changes in Consistency

As mentioned above, exposure to sunlight and heat while the hair dye is still in its original packaging can cause it to prematurely separate and affect its shelf life.

Once it has separated, the integrity of the hair coloring solution will quickly start to degrade.

Think about how hair dye is “supposed” to feel in your hands and hair.

The dye should also have a consistent texture. If its consistency has started to clump into pieces, become hard, or looks murky, the hair dye is probably bad.

Why Is Expired Hair Dye a Problem? Are There Side Effects?

While nobody buys perishable products expecting to use them once they’ve gone bad, you might wonder what’s so bad about expired hair dye. Are there actual reasons women shouldn’t use hair dye beyond its reasonable shelf life?

After all, you’re not going to consume it, and in any case, hair dye doesn’t typically come with a “Use By” date like food.

Even if it did, foodstuffs don’t magically go from perfectly fine to instantly rancid on the day after that “Use By” date, so what’s the big deal about using expired hair dye?

For one thing, as noted above, hair dyes that have gone bad can start to smell and become a cesspool of bacteria – not exactly the kind of mixture you want to go mixing into your hair.

Even setting that aside, expired hair dye can not only change color itself but using expired hair dye can cause your hair to change color. Unless you want your hair turned chlorine green, you’ll want to steer clear of bad hair dye.

Even if you do like green hair, there’s actually no telling what kind of color bad hair dye may produce, or even if you’ll get a single color or a rainbow of discoloration.

Even worse, using expired hair dye can cause allergic reactions, which in turn can cause an itchy scalp and redness.

Add to that the potential danger that comes with adding bacteria to your hair, and the danger of using spoiled hair dye starts to become clear.

How to Extend the Shelf Life of Hair Color

The simplest thing you can do to extend the shelf life of hair dye is to keep it sealed. This is true for drugstore brands and other DIY box dye kits.

That may seem obvious, but from the second the bottle is sealed in the factory, the clock is already ticking on its expiration. The second you open the bottle, you cause the hands of that clock to tick faster. Unopened hair dye generally has a longer expiration date.

The practical upshot of this is not opening a bottle unless you’re sure that you’re ready to use it. What’s more, it’s worth considering how much of the hair dye you are ready to use.

If you are only going to use a little, it’s worth considering whether you want to open a new bottle or if you can use one that’s already open.

You may also want to consider applying dry shampoo to your hair rather than wash it as much when dyeing. Washing your hair too much immediately after a hair dyeing session risks rinsing the dye out.

On the other hand, you might want to try and pre-shampoo your hair to prep it for your dye.

You’ll also want to make sure that you keep your hair dye away from any warm areas. In fact, you might even consider refrigerating it, though you’ll need to be careful not to overheat it.

Cool, neutral conditions away from light are the best storage option for hair dye products, including temporary and permanent hair dye.

In Conclusion

Hair dye can add a lot of color to your hair care regimen, but only if you make sure that it hasn’t passed the expiration date or prematurely spoiled.

While it may seem harmless, expired hair dyes can cause side effects. Spoiled hair dye can harm your scalp, lead to bacterial infections and potentially hair loss.

By keeping your hair dye in cool, well-controlled conditions, being careful about when you open it, and looking out for warning signs, you can get the most out of your hair dye and ensure that it remains good for as long as possible.