Many of us may not know that remaining box hair dye that you have purchased can be kept, sealed and used again if it hasn’t been mixed with peroxide. You can’t reuse leftover dye if it has been mixed with peroxide. You have no other option but to throw it away. If you are new to colouring your hair at home, there are different types of box hair dyes which are temporary, semi-permanent, demi-permanent and permanent colour. Permanent dyes have a longer shelf life than other types of dyes which is around 4-5 years. However, it is important to verify the expiration date of any dye before you use it.

box hair dye

Our salon has many clients who ask our hairdressers, “Can I dye it again after I have opened it?” The conclusion is, yes, it is possible to use it again if it hasn’t been mixed with peroxide. What does this mean?

Permanent dyes is used by mixing with peroxide. Peroxide is the chemical reaction that allows hair colour to penetrate into the hair. Mixing peroxide with both the tube dyes used in professional salons and the box dyes found in supermarkets or pharmacies is necessary. So, let us ask you a question. What do you do with dyes that have been mixed with peroxide already? You can’t use the dye again if you have already mixed it with peroxide. Once you have completed the hair colouring process, the only choice is to throw it away. You can save the dye if you don’t mix it with peroxide. All of the information we have discussed so far is applicable only to permanent hair dye.

box hair dye

What happens if the dye leftover is semi-permanent? 

Semi-permanent dyes can be a completely different ballgame. Semi-permanent dyes are usually packaged in small packs. Only some of them are packaged in resealable bottles. These semi-permanent dyes are only reusable it came in with containers that are resealable. You can’t re-use it if it comes in a package.

Practically, peroxide is use together with semi-permanent dyes. Instead, they react easily with oxygen so if the container isn’t sealed tightly, the dye will be losing their effectiveness and no longer work on the hair after the dye application. Now you know what you should do if there is leftover dye. However, dyes that come in tubes and box dyes are both available, as we have already mentioned. Every type of animal has its own storage requirements. We will share with you what are the requirements.

Leftover Box Dye: What can you do?

There are many choices when you visit a beauty or pharmacy shop to purchase hair dye. A colour kit is the most common option. A colour kit is a small box that contains everything you need to colour your hair.

  • Tube of dye
  • Peroxide
  • Hydrating oil
  • Post-colour treatment
  • Gloves

At times, you will just need to touch-ups at the root colour. For such small area, you should not be using the entire tube of dye. Even if you squeeze out half of the tube dye, you’ll end up with more than sufficient dye. Mix half the dye tube with half the peroxide jar with the hydrating oils to achieve this. There will be approximately half a tube dye and half a container of peroxide left. Apply the colour according the directions and you are good to go.

box hair dye

You might be asking, “What do I do with the leftover?”

After using the mixture for the root touchup application, you may have some leftover and you probably wonder what to do with it. If there is any leftover of mixture for this case, do not save it. This is because, after 30 minutes, the mixture will stop working so it’s useless for anything and can be thrown away. The dye tube and peroxide jars should be kept separate. It is best to keep everything together in the original box kit so that things will not be separated and get lost easily.

Permanent Dye in A Tube Which Contains Peroxide

You might be able to purchase the peroxide, dye tube and gloves separately at a beauty or pharmacy shop. This is an option for those women who are more experienced in dyeing their hair at-home. Take a moment to consider all the steps of what you are going to do before mixing the dye and peroxide. Also think about the amount of dye the you need for the area and amount of hair your are applying?

Do you plan to dye your entire head or just your roots touch up?

You will need to use all of the dye in the tube and all of the peroxide if you want to apply on your entire head. If it’s a minor root touch-up, you can use half the dye tube and half the peroxide jar. You should throw out any leftovers. It will be useless and no longer has any chemical effect on your hair after half an hour. Peroxide is usually packaged in sealed jars that can be kept for as long as you need them. Besides, peroxide is a chemical that reacts at high temperatures so it is important to keep them away from heat or any exposure to the sunlight. It will lose effectiveness if it comes in contact with heat or the jar of peroxide may even explode. Let us now share with you more about semi-permanent colours.

Can You Keep The Leftovers of Semi Permanent Dyes?

Semi-permanent colours are mostly available in bright colours. They can be applied to damp or wet hair and don’t need to use with any peroxide at all. These semi permanent products are easily available in hair care shops and pharmacies. You can find them in both containers and packets. Semi-permanent dyes that are stored in small packets cannot be kept or reused because they degrade over time as they are very susceptible to oxygen.

This means that once the packet is opened for a while, the dyes will not be as effective on the hair as compared to the results when you performed the hair application immediately after opened.  Semi-permanent dyes that are stored in plastic containers or jars are a different story. Because they are sealed with an airtight lid, the dye won’t deteriorate and can be used again and again simply because there is no oxygen reaction.

The only step you may need to perform is bleaching of hair before the dye application. In order for any bright vivid hair colour application to take effect, it is important for the bleach to achieve a buttery yellowish like blonde colour before you carry out the dye application. Apply the dye to damp hair and let it sit for a while before rinsing. You can save and keep the dye leftovers if it is originally stored in a air-tight container. This will allow you to know that it is ready for reuse again. It is very important to take not to keep it out of direct heat.


You now know how to save money on dyeing your hair as you can keep and reuse the leftover dye tubes and bottles of peroxide after colouring the hair. These tips will help you save money on your beauty routine.

If you need any professional advice on any kinds of hair colouring, you may book a free consultation at any of our Hera Hair Beauty salons in Singapore! Here at Hera Hair Beauty salons, we have highly experienced and skilled international stylists expertly trained in all hair colouring techniques ready to guide you through every step of your hair transformation journey.

To book your appointment click here ,

or call to book at +6592371254

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