Does Hair Dye Expire? How to Tell if Your Hair Dye is Safe to Use

Have you ever noticed how most hair dye products don’t come with expiration dates? For the manufacturers, it’s because all the chemicals in the dye help preserve the product for an indefinite amount of time, especially when stored in a cool dry place.

But for us consumers, this can make things a bit confusing, especially if you’ve got an old box of unopened dye at home, or an extra squeeze from when you last colored your hair. You might find yourself wondering whether that hair dye is expired, or still safe to use.

Well, here’s the answer:

Does hair dye expire?

The short answer is yes, hair dye does expire. While the chemicals in the dye can slow this progression, these chemicals can also stop working or separate over time. The question is after how long, and this depends on a variety of factors, including the type of dye, whether it’s a premium or drug store brand, and the conditions in which the dye is stored.

On average, permanent hair dyes can last for around 3 years, while it’s about 2 years for semi-permanent dyes since they contain less harsh chemicals than their permanent counterparts, and a mere 3 months for henna and temporary dyes since henna hair colors are typically derived from plant products.

Of course, this is all under the assumption that the container is unopened and stored under proper conditions. So, how about an opened box of hair dye?

How long before an opened box of hair dye expires?

Now, this gets tricky. If the box has been opened but you haven’t touched the mixtures and chemicals, permanent and semi-permanent hair dyes can still last for about 1 to 2 years, although the recommendation of most manufacturers is to use the dye within 6 weeks if you want to ensure accurate color results.

Again, this time frame is for professional grade colors stored under the right conditions. Cult products, drugstore brands, and at-home coloring kits will go stale much quicker, and all the more so for natural-based hair color treatments.

Having said all that, if you have already mixed the dyes, whether in preparation for a hair coloring session that you got lazy to do, or some leftover dyes from your last session, the mixture will go bad in a matter of days. You can still attempt to use the product as it likely won’t cause any adverse reaction, but you likely won’t achieve stellar results. Read also: Best black hair dye.

How to tell if your hair dye is expired

For an opened box of dye, whether it’s been mixed or not, there are lots of clear indicators as to whether that dye is still safe to use, such as extreme color changes of the dye being a dead giveaway. Here are some ways you can tell whether your hair dye is still good to go:

Look for changes in the product

• A murky appearance, in which case the chemicals in the dye have separated and the hair dye looks like it needs to be stirred or shaken in order to re-incorporate the mixture. Hint: don’t do it, it won’t work.
• A watery liquid sitting on top of the dye, or an orange or yellow liquid anywhere within the dye (or around the lid) are also indicators that the chemicals in the dye have separated and the product isn’t safe to use.
• A strong, unpleasant odor, likely the cause of contamination with fungi or bacteria since the box is open and exposed to the elements. Again, it’s best to just toss the dye into the trash at this point.
• Any change in smell can also be a sign of expiration, whether it’s the dye smelling a lot more potent or having a weaker odor than you would expect.

Look for changes in the packaging

Now, if your hair dye is still in the box, unopened, what you have to watch out for are changes in the packaging. At the very least, this will tell you if the hair dye is being stored under proper conditions. Look for any dents, swelling, or sogginess, as well as cracks, leaks, and caking. Any of these can mean that air is leaking into the product, thereby causing oxidation.

That said, regardless of the state of the packaging, the dye itself might still be okay to use, so what’s really important is to inspect the dye itself.

Side effects of using expired hair dye

After a certain amount of time (again, depending on the type of dye and the storage conditions), you can expect that the box of hair dye you’ve got sitting on your shelves won’t work effectively. While it technically won’t be dangerous to use, using expired hair dye does come with potential side effects on your hair and scalp.

For instance, temporary and henna hair dyes can quickly become stale, which means that the color will fade very fast once exposed to air. The same is largely true for other types of hair dye. Meaning, if you use an old box of dye, you can expect a faded look (aka not as much intensity and pigmentation) that will fade even faster.

Other side effects include:

• Greenish discoloration especially on gray, white, or blonde hair, largely due to oxidation of the hard metals in the dye, such as copper
• Wrong and/or uneven colors (or no color change at all), since there’s no telling how the dye has reacted over time
• Frizzy and brittle hair strands (or in the rare occasion, even hair loss), which can be a result of changes in the hair dye’s chemical makeup
• Burning sensation on your scalp and around the forehead, ears, and skin, caused by the harsh chemicals in the hair dye, such as hydrogen peroxide, ammonia, resorcinol, and paraphenylenediamine (PPD)

All the chemicals we just mentioned can cause that burning sensation whether you’re using a new or old box of dye, but the oxidation that happens with improperly stored dye can exacerbate this burning effect.

Not to mention, there’s always the risk of allergic reactions, again regardless of how old your hair dye is. This can present as anything from minor redness and itching to irritation, sores, hives, swelling, difficulty breathing, and full-on anaphylaxis.

Final tips

While some manufacturers may claim that their hair coloring products don’t expire or can sit on the shelf indefinitely, it is the general understanding that hair dye can last anywhere from 6 weeks to 3 years depending on the type of dye to the storage conditions.

If for some reason you feel like stocking up on hair dye, here are some ways to help keep it in pristine condition and working perfectly once you’re ready to finally use it:

Don’t open the box. Keep the hair dye mixtures sealed and untouched to prevent any reaction or contamination. Remember, your hair dye likely contains ammonia, which is a thriving environment for bacteria and microorganisms.

Store the dye in a cool, dry place away from sunlight. Heat will warm up the chemicals and cause them to separate, while air and moisture can damage the packaging and cause oxidation, especially if the dye contains peroxide.