Does Hair Dye Expire? Here's What You Need to Know

If you're someone who dyes your hair at home, you've probably had the experience of encountering an unopened, old hair dye box that's past the expiration date. But should you use this particular box of hair dye, or will it result in damaged hair and other unwanted side effects?

VEGAMOUR talked to a hair color expert to discover whether you need to worry about that expired hair dye lurking at the back of your bathroom cabinet. Plus, discover the color-safe products you really need to nourish your hair from root to tip.

Does Hair Dye Expire?

If you're rediscovering an old box of unopened hair dye, are the expiration dates important? According to vegan hair and beauty expert Liis Hainla, yes!

"Hair dye does expire," she explained. "The life span of a hair dye can vary depending on the type and how often it is used, but in general, most dyes will last about 6-12 months after opening."

If your unopened dye is in damaged packaging or you're wondering whether to use already opened hair dye or even mixed hair dye, it's best to trash it since the shelf life of an opened product is fairly short. But in general, box dye from many drugstore brands lasts for a longer period when properly stored.

Hainla said that using expired hair dye can have negative effects. "After some time, hair dye can form chemicals harmful to your skin and hair, which can cause irritation or an allergic reaction," she explained.

Allergic reactions to expired permanent hair dye or semi-permanent hair dye might include a burning sensation, scalp itchiness, hair loss and other negative effects. Ingredients in semi-permanent and permanent dyes like hydrogen peroxide, ammonia, resorcinol and paraphenylenediamine are more likely to cause allergic reactions the longer they sit on a shelf or in your bathroom cabinet.

"If you experience any of these symptoms after using expired hair dye, immediately stop wearing it and wash your affected areas with regular soap and water," advised Hainla.

Read More: How Long Does Hair Dye Last? Plus, 5 Tips to Make It Last Longer

How to Safely Store Your Hair Dye

Most hair dye manufacturers say their dyes will last past the expiration date if stored correctly, but Hainla explained that this is only true if you carefully store them in an appropriate manner.

"Hair dye can be harmful if not stored properly, so it is important to follow a few simple tips to avoid potential damage," she said. "First and foremost, make sure that the hair dye is kept out of direct sunlight or heat. This will help to prevent oxidative damage and deterioration."

Both sunlight and heat are can cause your dye to change color from exposure, becoming less effective and altering the stability of the chemicals within the permanent dye. If you use hair dye that's been overexposed to sunlight, it might not take or your hair might turn out a darker shade than you expect. To prevent this, keep any hair dyes you aren't ready to use safely tucked away in a cabinet, box or other light-blocking containers.

Hainla said exposure to oxygen could be as damaging as exposure to heat and light. An unscrewed bottle cap can cause damaging leakage. "Keep the bottle cap on tightly when you’re not using the hair color product," she said. "This way, the liquid won't seep into the container and cause corrosion." If your hair dye leaks out of the bottle, it might oxidize or gel, creating a foul odor and altering the color and composition of the dye."

Last but not least, Hainla said that hair dye should be kept on its own away from other chemicals in your bathroom. "Store your hair color in an airtight container away from other chemicals or foods that might contaminate it," she said. If your hair dye smells foul or has an off color, it might have mixed with another chemical and should be trashed immediately.

How to Tell if Old Hair Dye is Safe to Use

If your expired hair dye is closed, packaged and properly stored, Hainla said that it still might be safe to use on your strands, but it's important to practice caution.

"The best way to tell if hair dye is expired is by the date printed on the bottle or squeeze tube. If that date has passed, then it’s best to throw the dye away," she said.

However, just because that sell-by date hasn't come yet doesn't mean that your dye is at its peak. If you have an older bottle or box on hand, Hainla said that it's important to double-check before using, even if the expiration date has yet to come.

"If your dye hasn’t expired but you’re still not sure whether it’s okay to use, do a visual inspection of the product for signs of age, such as clumps or flaking," she recommended. "If either of these is present, it's likely that the product should not be used and instead replaced. If you don’t notice anything different with the product, then it’s probably safe to use."

Hair dye is relatively inexpensive and can do serious damage to your strands if it's gone bad. When in doubt, it's best to find another mode of self-expression or go back to the drugstore for a replacement box.

Read: How to Prepare Hair for Bleaching

The Best Way to Upkeep Colored Hair

Once you've got your new box of dye in hand, Hainla had plenty of recommendations for helping your hair color stay at its best for as long as possible.

"To make sure your hair color stays vibrant longer, as a hair-care expert, I suggest avoiding using harsh shampoos or conditioners that contain sulfates or parabens," she said. "

Switch to a natural shampoo and conditioner duo that gently cleanses your strands while protecting them from environmental damage and strengthening them from the inside out. Because dyed hair tends to be lacking in moisture, you should condition every day to make sure your strands are nourished and supported, but keep your shampooing to a minimum to avoid stripping your hair of its natural oils.

"When it comes to styling, try not to overdo it by wearing too many hair products or putting excessive heat on your locks," said Hainla. Dyed hair is naturally more porous and fragile than undyed strands, so using damaging styling tools not only fades color, but it might also lead to stress, breakage and other hair problems down the line.

Read: How Often Can You Dye Your Hair?

A Color-Safe Haircare Routine

Aside from not using expired hair dye, one of the best things you can do to protect your hair from damage and distress is to follow a color-safe haircare routine that supports and nourishes each and every strand from the inside out. Support your locks with products that feature clean, high-performing, plant-based ingredients for optimal scalp and hair wellness. Toss that expired hair dye and start treating your strands right! Your hair will thank you later.

More From VEGAMOUR

• Shop: Color-Safe Shampoos and Conditioners
• Thinking of Going Copper? Here's How to Upkeep Your New Hue
• Can Hair Dye Cause Hair Loss?
• How to Cover Gray Hair

Photo credit: Maria Geller/Pexels