When it comes to new styles, colors, cuts, and hair trends, you often hear people say, “It’s just hair. It’ll grow back!”
We say, go for it!
Whether you want to do pastels, a dip-dye, maybe just go a tone warmer or cooler, dyeing your hair is a quick and easy way to stay on top of trends or just to change up your look.
But not all dyes are created equal, of course!
And depending on your need, you might want one that lasts longer to maintain a certain look or maybe something you can change at the drop of a new trend.
You might just want to change up your look to suit a certain season, or maybe you’re looking for something more of a long-term change.
Well, there’s a dye for just about anyone’s needs, whether you want it to last a day, a week, or a month or two!
Hate to break it to you, but permanent hair dye doesn’t really last forever.
Now, while that may not seem like quite a shock, some people might think they’re in for a long-term commitment when they try out permanent hair dye.
However, you can usually go only 6-10 weeks without re-touching or recoloring, depending on how it’s applied and maintained. 1
But don’t worry! This isn’t because the color fades or washes away.
On the contrary, the way permanent hair dye works is by embedding color right into your hair. If processed properly, the hair shaft opens up and absorbs this color, making it pretty resistant to just regular washing.
The only reason why it’s recommended to get a re-touch every month or two is that this is how long it takes for your hair to grow. Your roots will start showing by the end of 4-8 weeks, and the dye job won’t be as consistent.
But of course, the length of time before your next re-color depends entirely on how fast your hair grows.
You can take this as a sign to get your roots touched up, or maybe think of shifting to another color!
We wouldn’t recommend cycling through colors too quickly, though, because having to re-process your hair would mean possible damage as well.
Although damaged colored hair can be fixed by a hair bonding treatment like Olaplex, prevention is still better than cure.
Unlike permanent hair dye, semi-permanent dye starts fading at the 4-6 week point.
This is mainly because of HOW semi-permanent hair dye colors your hair. Unlike permanent dyes, semi-permanent hair dye only coats the outermost layer of your hair.
As a benefit, this means it is less likely to damage your hair. It doesn’t need any peroxides or ammonia, which are notoriously drying and damaging as well. 2
So for someone who just wants a quick change-up, then semi-permanent hair dye comes with the perks of a fast color change without the commitment or damage.
If you wanted to prevent damage and had the time and patience to recolor, you could even swap out your permanent dye for something semi-permanent. It’ll do the trick for as long as you touch up once you notice fading.
However, if you’re looking for something that can withstand a month’s worth of washing, and want salon-vibrant hair for a whole two months, then permanent hair dye would be a better option.
Semi-permanent dyes are also great for those experimenting with coloring for the first time. You can try out a new trend without having to commit to longevity and damage.
If you like it, then you can go for something more permanent once it fades. If it’s not for you, then you can wait it out and watch that color go down the drain after a few weeks’ showers.
Also known as a gloss or a stain, semi-permanent hair color works by surface of your hair.
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Demi-permanent hair color hits that sweet spot right in between the benefits of semi-permanent and permanent colors.
While semi-permanent hair dye is like a gloss or a stain that sits on top of your hair, demi-permanent dye has just enough peroxide to let color penetrate your hair shaft, just like a permanent one would. 3
However, it doesn’t have the peroxide that causes permanent dyes to be a bit more damaging. What a combo!
Demi-permanent dye is a lot better for darkening hair than it is for lifting colors. So, that may be one downside to it. But because of this, it’s a great, safe option for covering up grays.
While it is a similarly vibrant option, unfortunately, it doesn’t have the longevity of permanent hair dye. The way it penetrates hair only lets it last for 10-12 washes, so it really depends on how you maintain it.
But it is often preferred because of its minimized chemical damage and bright results. It’s also great for people with more textured hair as its chemical components won’t straighten out your curl pattern.
Does it just coat your hair like a semi-permanent dye? It’s probably going to wash out soon.
Does it involve some chemical process that opens up the hair shaft? It’s likely to last longer.
But in the case of most temporary dyes, it’s the stain or gloss-type effect that you’re likely going to achieve. Especially when you’re using more natural dyes such as vegetable dye and henna, these can last you up to a few weeks max.
There are one-time use temporary hair colors that come in sprays, wax, shampoos, hair mascaras, or even chalk!
Semi-permanent hair color can also be called a stain or a gloss. This is because its mode of action involves covering the hair up with color only on the surface. It usually lasts up to a few weeks before eventually fading.
Demi-permanent hair dye, on the other hand, is a hybrid between permanent and semi-permanent colors. Like a permanent dye, it has some ammonia to open up the hair shaft to embed color, making it more vibrant.
However, it does fade like semi-permanent hair dye as it doesn’t lift as much as permanent processing does. This also means it’s a lot safer for sensitive hair.
Demi-permanent hair dye is also peroxide-free and alkaline, making it safer and less drying for the hair than permanent dyes.
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The quick answer is it depends.
Semi-permanent dyes could fade completely within weeks as it only coats the outermost layer of hair. It can get washed out by shampooing and will eventually fade away. 5
Permanent hair dye might take a while longer to fade. When using permanent hair dye, it changes the structure of your hair to take on a different color. This means it will be more persistent than a dye you can wash away.
However, it can start to fade as well. But because of how it changes the hair on a molecular level, it won’t ever fade away completely, unless you grow out your hair and cut it off.
It depends on what your concept of permanent is.
If what you want “permanent” to be is something that will never need any touch-ups, then you’re out of luck. You’ll still need to do retouches once your roots grow out or when the environment (like light, washing, and pollution) starts to affect your hair color.
But when it comes to the effects of getting permanent colors done, it’s definitely permanent. What does this mean? Once a portion of your hair is processed with permanent dye, the structure of your hair is changed forever.
That dyed portion has undergone chemical changes that allowed it to be the color you dyed it to. So, it’s never just going to fade back to your natural color on its own.
A completely unopened package of hair dye can last months on the shelf. But once you open it up and start preparing the mixture, make sure there’s no turning back--at least in the next 30 minutes.
If you’re wondering “How long does hair dye last after mixing?”, then the answer is 30 minutes to an hour (max!)
Hair dye and developer mixed together cause a chemical reaction called oxidation. Chemical reactions are often pretty quick and irreversible, so if you don’t have those thirty minutes to work quickly, better reschedule your dye job for another day!
Never use mixed hair dye that’s been left out for more than 30 minutes to an hour — best case is you’d end up with a bad color. But the worst case we really want to avoid is some permanent, irreversible chemical damage to your hair and scalp.
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So now you know! Whether you want something that’s more long-lasting, something that will fade in a couple of weeks, or maybe even just some color for a day, there’s a dye option out there for you.
All you have to do is figure out what you need, how healthy your hair is, how much chemical load your hair can take, and you’re all set!
Don’t even worry about experimenting.
Just like the trends, your dye can be hair today, gone tomorrow if you want it to!