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We’ve all been there. You have some leftover hair dye or developer from the last time you did your hair, and now you want to use it. Or maybe you forgot you bought extra, and it’s still unopened! Is it still good? What’s the worst that could happen? We’ve done the research to give you the answers to these questions and more.
Both hair dye and developer have limited shelf lives; they both expire.
- Unopened permanent hair dye and unopened developer can last up to 3 years. In comparison, unopened semi-permanent dye lasts up to 2 years.
- Previously opened hair dye that is closed and properly stored should be used within 1 year and developer within 6 months.
- Other factors can speed up the expiration of both products.
Expired hair dye or developer can be easy to spot once you know what to look for. Proper storage of these products is super important. Using expired hair dye or developer can have unintended outcomes on both your look and your health. When in doubt, throw it out!
Keep reading to learn the tell-tale signs that your hair dye or developer is expired and what can happen if you still decide to use it. We’ll also elaborate on the specifics and let you know what you can do with that unused dye.
How Long Can You Store Hair Dye?
Unfortunately, it’s not an exact science. Many manufacturers say unopened hair dye can be stored indefinitely. But the actual shelf life of the dye depends on the kind of dye and the storage conditions.
Hair dye is best stored in a cool, dry place, away from direct sunlight. Peroxide and ammonia are common ingredients, and they react quickly to heat. Storing hair dye in environments with high heat and humidity can degrade the chemicals and speed up expiration.
When stored properly, professional and permanent dyes can last up to 3 years. Semi-permanent dyes and most popular drug store brands last up to 2 years. This difference in shelf life is due to the types and strengths of the chemicals involved.
Once opened, if stored properly, you can keep hair dye for up to a year. However, some manufacturers suggest using hair dye within 6 weeks of opening for the best results.
How To Tell If Hair Dye Or Developer Is Expired
First, look at the packaging or bottle. If the box or bottle is swollen, wet, leaking, dented, or otherwise damaged, throw it out. These could be signs of oxidation, suggesting that the chemical composition may have changed. Another possibility is the contamination of the product by bacteria or fungi.
If everything looks good on the outside, it’s time to open it up. A yellow or orange color around the lid means air got in. Toss it. Any major color changes to the dye or developer are another giveaway. Expired dye will often appear separated or milky rather than smooth. Expired developer may be extra liquidy or have a yellowish tint.
If you noticed a sour or spoiled smell when you opened the dye, this is another sign of unwanted bacteria. It’s done.
What Happens If You Use Expired Hair Dye Or Developer?
Using expired hair dye or developer can result in a range of effects, from simply wasting your time to requiring a call to your salon or doctor ASAP. Ultimately, it’s just not worth the risk. You may end up spending more time or money than if you just bought new products from the beginning.
The likely best-case scenario is that the expired dye or developer won't work. If it does work, you might get a slightly darker shade than intended. Other possibilities are uneven color, greenish hues, or color that fades very quickly. Expired dye or developer could also lead to damaged, frizzy hair.
Other possibilities include allergic reactions or burns to your scalp. These things can happen to some people with skin sensitivities even if the product is not expired. Once expired, we are talking about a change to the chemical composition of some powerful chemicals. If you notice any itching or burning when using your dye or developer, rinse it out right away.
Can You Use Hair Dye If You Left It Opened Overnight?
If you left your hair dye opened overnight, you should still be able to use it with a few conditions in mind. Make sure that your dye has not been mixed with the developer and that it has not been left in direct sunlight or exposed to heat. If you don’t see any signs of expiration, you’re good to go!
Can You Save Hair Dye After It's Mixed With Developer?
No. Do not save this potentially dangerous combo. Once your dye and developer are mixed, you have one hour at most to use it.
What Can You Do With Unused Hair Dye?
Unused hair dye can be great for touch-ups. It also comes in handy when you realize you didn’t buy quite enough to get the job done, but you remember you saved some from last time.
If you recently dyed your hair and have some unmixed product left, grab a sharpie, and write the date opened on the bottle. Store it in a cool, dark, dry place, and pay attention to any signs of expiration before your next use.
If your unused dye is not expired and unopened, but you want to try a new color, consider giving it away rather than tossing it.
If your product is expired, do not pour it down the drain. These chemicals can be dangerous if they get into the ground or local water supply. You can check out the US EPA website for info on local resources that aim to dispose of household chemicals safely.
Leftover hair dye or developer can ultimately save you some money and a trip to the store or salon. But it’s essential to consider the shelf life of these products. It’s not worth the time or money saved if you end up using an expired product. Bookmark this post and feel confident in the products you use the next time you do your hair!