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What Is Hair Developer | & Why Do You Need It?

What is hair developer? And why the heck do you need it? We’ll answer these questions and much more in our complete guide. Read on to learn all you need to know about hair developer.

Considering Hair Developer?

For a piece on what is hair developer, a number of these products in a lay flat image against a green background

The percentage of American women who dye their hair has grown from 7% in the 1950s to 75% in 2001. The number for guys is much lower in the US, at around 7%, up from 2%. 

If you fall into the “hair dyed” category, regardless of whether you have your hair colored in a salon or do it at home, you may not be aware of some of the processes involved in achieving that gorgeous color.

One necessary process is using a hair developer to lighten the hair. These chemicals play an essential role in hair lightening. Without it, your color simply wouldn’t look as good.

With that in mind, this guide will walk you through:

  • What hair developer is
  • Why you need it
  • What it does
  • How much you need to use

Let’s get started!

What Is Hair Developer?

What does hair developer do graphic

A hair developer is a liquid you mix with your hair dye that activates the color. Once the dye is activated, it opens your hair cuticles to allow the dye to penetrate your hair. The most crucial ingredient in a hair developer is hydrogen peroxide. This lifts your hair color.

Suppose you go to the salon to have your hair colored. In that case, you’ll likely have watched your colorist mix two separate liquids together before applying them to your hair. One of these is a hair developer.

Likewise, if you dye your hair at home, the box you bought from the drugstore or supermarket will have two bottles. Again, one is hair dye, the other is hair developer. You mix them together before applying them to your mane.

Suppose you want to buy professional hair color to use at home. In that case, you’ll have to buy your developer separately and use a specific volume depending on your hair type. 

Types of Hair Developer

What type of hair developer should I use?

Unfortunately, there’s no set answer to this question. Remember, the hair developer determines the end result of the coloring process; that’s why it’s super important to choose the right one. 

Hair developer comes in five different volumes. The one you opt for depends on the look you’re hoping to achieve. For example, if you just want a very gradual, subtle look, use a lower volume. If, however, you’re going all in and bleaching your hair for that sun-kissed beach look, you’ll need a higher-volume developer. 

The higher the hair developer’s volume, the more the hair cuticles open, making it possible for your natural hair pigment to be stripped from your locks.

The critical thing to remember is that the volume you choose doesn’t affect the long-term results of your hair color. 

Let’s take a look at the different volumes out there:

10 Volume Hair Developer

When to use a 10 hair developer

Hair developers can damage your hair. Fact. This volume hair developer is the one to go for if you’re aiming for the least damage and a gentler tone to your hair. It’s the obvious choice for anyone who doesn’t want to lift their base color; instead, they just want to add a tint or tone to their hair. 

20 Volume Hair Developer

When to use a 20 hair developer

If you want to lift your hair color a couple of levels or have a lot of gray showing (50%+), then the 20 volume hair developer is your friend. This is the one you mix with permanent or semi-permanent hair color to cover that gray.

If you have less than 50% gray, use the 10 volume instead. While you won’t get total coverage, the 10 volume will give your gray hair a highlighted look. If, however, your hair’s naturally blonde and you want to lighten it a bit, use a 20 volume.

30 Volume Hair Developer

When to use a 30 hair developer

Used when lightening hair by more than a couple of levels – it’s stronger, enabling the pigment to set in your hair shaft. It’s probably a good idea not to use this if your hair is very damaged because your hair could end up looking very dry and lacking in shine.

If your hair isn’t super porous and therefore doesn’t take color easily, 30 volume is a good bet for you. Some colorists will use this to lighten hair that’s light brown or medium brown hair. 

40 Volume Hair Developer

When to use a 40 hair developer

If you love highlights (who doesn’t?) and don’t want to use bleach, 40 volume will lighten your hair by up to four shades. If you’re doing this at home, we recommend that rather than going all-in with the 40, do a gradual process using 20 or 30 instead.

Then, be sure to use a ton of conditioner in-between coloring. That way, you’re protecting your hair and your scalp.

Remember, this stuff is strong. If you have black or brown hair and use this, you’ll get lighter hair. But this strength can damage your hair and burn sensitive scalps, so be careful. 

50 Volume Hair Developer

When to use a 50 hair developer

Yes, it exists, and no don’t use it. It’ll damage your hair, maybe even burn it. But, if you do go ahead, use a strong hair bond builder like Olaplex. If you use another hair repair treatment and lighten your hair gradually, remember to condition your hair and scalp each time.

Do You Really Need a Hair Developer?

Yes, of course, your results won’t be as long-lasting without it. Some home hair dye kits come without it, but our advice would be to lower your expectations.

How Much Developer Should You Use?

That depends. If the color you’re aiming for is close to your base color, i.e., no more than two shades different, the ratio is 1:1. I.e., if you use 100ml of dye, you also use 100ml hair developer. Simple.

If, however, you want to lighten your hair by three or even four shades, you need to use a 1:2 ratio, so if you use 100ml of dye, you use 200ml of the developer. This ratio will likely be adopted if you’re using 30 or 40 to achieve a lighter color.

So, What Is Hair Developer?

So there you go; we hope we’ve answered the question, “what is hair developer?” Armed with your newfound knowledge, you’re all set to add color to your hair, or you feel better informed ahead of your next salon visit. Good luck!