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4 Clever Ways to Use The Leftover Hair Dye

If you have gone through the DIY hair dyeing process, you know that the dye doesn’t always get used up. After purchasing the dye kit, following the instructions, and using it, you may have nearly half of it remaining.

Throwing away the leftover hair dye may feel like a loss since you spent your funds on the products. So, naturally, you may wonder if there is a way to use leftover hair dye in the future.

The answer differs depending on factors such as whether you have mixed the dye. Keep reading to find out more.

What To Do With Leftover Hair Dye

Let’s take a look at which hair dyes can be saved for later use.

Permanent Hair Dye

what to do with leftover permanent hair dye

When you mix hair dye with peroxide or developer, it causes the start of a chemical process that ensures the dye works. It enables the dye to penetrate your hair better for a great result. But once you mix hair dye with peroxide, it quickly loses effectiveness. If you keep this mixture for reuse, it will not work.

So, if you purchased a permanent dye kit and some of the mixtures of dye and peroxide remained, discard it. If some products remain untouched, keep them safe for future use.

Semi-Permanent Dye

Semi-permanent dye works differently. It doesn’t need to get mixed with peroxide to work. The hair dye comes in containers, jars, or packets.

You cannot save semi-permanent dye that comes in a packet. That is because the dye reacts with oxygen when you open the packet and becomes less effective.

If semi-permanent dye comes in a plastic container or a jar, you can reuse it multiple times. These storage containers are airtight, preventing an oxygen reaction and ensuring the dye remains effective over time.

Henna Hair Dye

Reusable Henna Hair Dye

You can reuse henna hair dye, a natural hair dye if you keep the powder in its package or an airtight bag in a dry place. Henna paste is reusable if you place it in an airtight container or wrap it with aluminum foil and freeze it.

Box Dye

Box dye is readily available in pharmacies and cosmetics shops. The color kit contains a tube of dye, gloves, peroxide, hydrating oil, and treatment. If you only need to do a root touch-up, you will likely have some leftover box dye. Any dye that has been mixed will need to be discarded.

If any dye or peroxide remains in their respective containers, save them for the future.

How To Dispose of Leftover Hair Dye (Dos and Don’ts)

How To Dispose of Leftover Hair Dye

Hair dyes contain chemical properties that make them dangerous to the environment. So, you must dispose of hair dyes correctly to ensure the safety of people and ecosystems. Make sure you throw leftovers in a hazardous waste container after finishing the process of dyeing hair. If the dye container has no chemicals, you can throw it in a mixed recycling container.

Don’t discard leftover hair dye in a common waste container if it still has chemicals. If you don’t have hazardous waste containers near you, take the leftovers to a nearby hazardous waste collection center.

It is good practice to look at your local laws on discarding hazardous waste. Doing so will ensure you properly throw away the leftover dye and accompanying containers. Your local government may also have easily accessible drop-off locations for hazardous waste. Use these if you don’t want to make the trip to the waste center.


Here are some commonly asked questions about leftover hair dye.

Can I freeze leftover hair dye?

No. For most hair dyes, freezing them will cause them to become inactive. Thus, they will not produce the desired result. The case is different for henna. You can freeze henna paste and reuse it later after defrosting.

Can I reuse leftover dye?

Generally, you can reuse leftover permanent and box dye if you have not mixed it with peroxide. You cannot reuse the mixture because it will become ineffective after some time. You can also reuse henna paste and semi-permanent dye if stored correctly.

How long does leftover hair dye last?

Leftover hair dye mixed with peroxide lasts 30 minutes to 1 hour before it loses effectiveness. The reaction between the hair dye and peroxide causes a rapid deterioration in potency. Here

Can I put leftover hair dye in my conditioner?

Yes, you can put semi-permanent leftover hair dye in your conditioner. Note that the resulting hair color will be less vibrant since the conditioner serves as a barrier. Mixing conditioner with permanent dye may cause uneven color application.

Whether you use permanent, semi-permanent, henna, or box hair dye, your primary concern is likely what to do with what remains. Now you know when to save the remaining hair dye for later and when to discard it.

The knowledge you have acquired will help you save some money. Also, knowing how to throw away leftover hair dye properly will help you become a better gatekeeper to the environment. With the information provided here, you are well on becoming better at dyeing your hair.

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