One of my readers recently asked a rather interesting question about saving unused hair dye. After I responded to her question it prompted me to research the matter a bit more to see what others had to say about the subject.
I was surprised to learn that the question had been asked quite frequently going back five years — at least that’s how far back I checked. I was surprised to see that this is something that some people have actually done. The responses to the question were pretty much all the same coming from different people from different walks of life.
Although it is possible to color our hair at home, we still have to follow the rules. Saving unused hair dye after it has been mixed is not recommended even if you are just coloring a portion of your hair. Discard any unused hair dye that has been mixed because it is said to deactivate after 30 minutes to an hour. And no matter what you do to it later on, you will not achieve any coloring results.
Don’t mix any saved hair dye with fresh coloring.
Using expired hair dye can result in producing the wrong color results, you could experience a burned scalp, other other issues may results such as itch scalp, or it may have no affect at all. What I learned, which was most fascinating, is that hair doesn’t usually have expiration dates but some some have a “use by date” and it is said that hair dye unopened with the tubes unpunctured has a shelf life of about a few years.
The worse that could happen is that it could oxidize, or just “turn off.” if the bottles look to have swelled, or after you open the bottles they look as if the liquid has separated, it is best to dispose of the product and purchase a fresh box. Even if you use half and half of the products, it is best to used the remaining product within a day or two or no more than a week before it loses its ability to provide the desired color results you are looking for.
To be on the safe side, I recommend consulting a hair care consultant. Better safe than sorry. Or just buying a whole new box, following the instructions as they are provided, and going from there.
I will update this information as I look into it more.
Savvy Hair Studio101 