Everything You Need To Know About Demi-Permanent Hair Dye

If you’re a hair color fanatic like us, then you’re probably aware that there are several different types of hair dyes to choose from. Permanent hair dye is arguably the most popular pick, but there’s also semi-permanent and demi-permanent hair dye—the latter of which is perfect for those seeking a low-commitment way to try a new hue. Whether you’re considering trying a demi-permanent hair color or just want to learn more about it, you’ve come to the right place. Ahead, we’ll explain what demi-permanent hair dye is, how it differs from semi-permanent dye, and offer advice on who demi-permanent color is best suited for.

What Is Demi-Permanent Hair Color?

You likely know what permanent hair dye is, and chances are good you’re familiar with semi-permanent dye—but what does demi-permanent mean? Put simply, demi-permanent hair color is a type of hair dye designed for a long-lasting, yet temporary, change. These formulas are ammonia-free and deliver a wash of color that can last for a month or longer, depending on how frequently you shampoo your hair. Professional hair glosses often fall into this category, but you can also buy demi-permanent dyes to use at home.

How Demi-Permanent Hair Dye Works

In order to understand how demi-permanent hair dye works, a brief chemistry lesson is in order. Permanent hair dyes—both salon options and boxed dyes—typically contain ammonia and a developer. The ammonia lifts your natural color so your chosen hue—be it beachy blonde or vibrant copper—can show up as intended. The developer, meanwhile, opens up your hair’s cuticle so the dye pigments can penetrate into your hair’s inner cortex. The chemical reaction that occurs with the use of ammonia and developer ensures the color pigments will stay in your hair, regardless of how many times you wash it (though they may become less vibrant over time). 

Demi-permanent hair dyes, however, only contain a small amount of developer (and no ammonia). As such, these formulas won’t lighten your hair or significantly alter your natural hue. Instead, the developer allows the dye pigments to lightly penetrate the hair, providing a tint of color that gradually fades with each shampoo. 

Demi vs. Semi-Permanent Hair Color

The primary difference between demi- and semi-permanent hair color is that the former contains developer, while the latter doesn’t. As explained above, the small amount of developer in demi-permanent hair dyes allows the color to penetrate the hair’s cuticle. This allows the color to last up to a month or more. 

Semi-permanent dyes, however, are formulated without developer. The pigments in these formulas simply coat the surface of your hair and gradually wash away with each shampoo. While this is ideal for those seeking a damage-free way to change their hair color, it also makes semi-permanent dyes fade fairly quickly—usually, within a week or two. The L’Oréal Paris Colorista Semi-Permanent Hair Color is a perfect example of this type of hair dye. It comes in a range of bold hues and delivers vibrant results that last for 10+ washes.

How Long Does Demi-Permanent Hair Color Last?

Like any hair color, how long demi-permanent hair dye lasts depends on several factors, including the formula used and your haircare routine. However, you can expect most demi-permanent dyes to last between 24 and 28 washes—roughly a month to a month and a half, depending on how often you wash your hair.

Factors that can affect how long demi-permanent hair dye lasts

Factors that can cause your demi-permanent dye to fade more rapidly than you’d like include: 

• Washing your hair too frequently: Demi-permanent dye gradually fades each time you shampoo. To extend the longevity of your color, it’s a good idea to adjust your shampoo schedule. Try lathering up once every few days instead of every day, and use dry shampoo on non-wash days to keep greasy roots at bay.

• Heat styling: Exposure to high temperatures can damage your hair and cause your hair color to fade or lose its vibrancy more quickly than expected. Stick with heat-free hairstyles when you can, and if you must blow-dry or flatiron your hair, be sure to prep your strands with a heat protectant first (we love the L’Oréal Paris EverPure Sulfate-Free Moisture 21-in-1 Leave-In Conditioner for Dry Hair).

• Sun or chlorine exposure: If you’re coloring your hair in the summertime, be sure to snag a hat to wear while outdoors. Sun exposure can cause your hair color to fade more rapidly than it otherwise would. Chlorine can affect your hue, too—so limit your time in the pool, if you can. 

• Exposure to hot water: Long, hot showers feel great after a hard day’s work, but they can be hard on your mane. To help prevent your everything shower from stripping your color, try bathing in lukewarm (rather than hot) water. 

• Not using color-safe products: Using color-safe haircare products is one of the best things you can do to help preserve the life of your color (demi-permanent or otherwise). Consider swapping out your go-to shampoo and conditioner for a duo designed for color-treated hair, such as the L’Oréal Paris EverPure Sulfate-Free Bond Repair Shampoo and L’Oréal Paris EverPure Sulfate-Free Bond Repair Conditioner. The pair is suitable for all hair types and helps smooth and strengthen damaged, color-treated hair. 

Is Demi-Permanent Hair Color Damaging?

Since demi-permanent hair dye doesn’t contain ammonia, it’s generally considered less damaging than permanent hair color. However, it’s not quite as gentle as semi-permanent color, as the color pigments do penetrate your strands. Still, it’s a low-damage option perfect for those who want to rock a new hue without subjecting their strands to unnecessary stress. 

When Should You Use Demi-Permanent Hair Dye?

If you’re wondering whether demi-permanent dye is right for you, keep reading. Below, find a few situations in which it may be worth opting for a demi-permanent hair color over other types of hair dye.

When you want to try a new color

We often find ourselves scrolling through TikTok and Pinterest, trying to determine the perfect new hue to color our mane. If you’re like us and frequently find yourself torn between options, try a demi-permanent hair dye. This will give you the freedom to try a different hue each month (or after around 24 washes, whichever comes first).

You’re not ready to commit to permanent color

A demi-permanent hair color is ideal for those who aren’t quite sure if they want to commit to a new ‘do. The color will last longer than its semi-permanent alternative, allowing you to get a better feel for whether you want to color your locks permanently. If you decide the hue isn’t for you, no worries—after around 24 shampoos, you’ll be back to your starting hair color sans damage.

To refresh dull, lackluster hair

If your mane is looking a little lackluster, a demi-permanent hair dye is an easy way to give your locks a refresh. Use one in a shade that’s close to your natural hair color to enhance your natural hue and give your mane added depth and dimension.

When you’re looking for a low-damage hair transformation

Since demi-permanent hair color doesn’t contain ammonia, it won’t cause damage like other hair color options might. This is an ideal option for those who want to color their strands without risking damage or breakage.

To go darker (temporarily)

While demi-permanent dyes can’t lighten your hair, they can darken it. If you’re a blonde toying with the idea of going to the dark side, testing your desired hue with demi-permanent hair dye may be the perfect option for you.

How To Take Care of Demi-Permanent Hair Color

Once you decide to try demi-permanent hair dye, it’s essential to learn how to maintain your new hue. Follow the three tips below to help care for your newly colored strands the right way.

1. Switch to a color-safe system

Using haircare products specifically designed for color-treated hair is a must if you dye your hair. To help keep your color looking fresh and vibrant, try the L’Oréal Paris Elvive Color Vibrancy Protecting Shampoo and L’Oréal Paris Elvive Color Vibrancy Protecting Conditioner. The antioxidant-packed duo is formulated with protective UV filters and helps lock in color vibrancy for brilliant, lasting color. 

2. Wash with lukewarm water

While there's nothing like enjoying a hot, steamy shower, you may want to scale back on it once you opt for demi-permanent hair color. Super-hot H2O can strip your hair of its natural oils, leaving you with a dry and dull mane. Simply turn down the dial in the shower to keep your strands and your hair color in mint condition. And if you’ve indulged in one too many hot showers and need to infuse some shine back into your hue, reach for the L’Oréal Paris EverPure Sulfate-Free Glossing Shampoo and L’Oréal Paris EverPure Sulfate-Free Glossing Conditioner  once or twice per week. The luxe pair cleanses, moisturizes, smooths, and boosts shine for healthy-looking hair. Finish things off with the L’Oréal Paris EverPure Sulfate-Free Glossing 5-Min Lamination Mask for up to five days of intense, glass-like shine.

3. Minimize heat styling

As we mentioned, heat styling can take a toll on your color-treated hair. To help protect your new hue from premature fading, try to limit your use of hot tools as much as possible. If you can’t totally part ways with your blow dryer (understandable), that’s okay—just be sure to protect your strands with a quality heat protectant first. The L’Oréal Paris EverPure Bond Repair Oil-in-Serum is an excellent pick—it strengthens the hair, boosts shine, and helps shield strands from temperatures up to 450 degrees Fahrenheit.

Next Up: How To Dye Hair at Home in 8 Easy Steps

Photo courtesy of L’Oréal Paris