Dying hair by yourself is all fun and games until you’ve to choose the right hair developer to use. The most asked question in this regard is — does developer damage hair. We’re gonna answer it by thoroughly explaining ins and outs of developers.
For now, let’s look into the basics of hair developer and the cautions that need to be adopted to avoid hair damage caused by the developer- or else results won’t be worth your efforts.

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What Does Hair Developer Do?
Hair developer is a product that changes hair color by altering or removing unwanted hair pigments. It’s named so as it primarily develops hair color. It comes in powdery and creamy forms and is composed of lightning agent hydrogen peroxide along with some color imparting chemicals such as ammonia and p-phenylenediamine. Thus it’s also called as peroxide or activator.
These chemicals open up the hair cuticles and let the color penetrate the cortex, deeper into the hair shafts. The color-imparting chemicals in hair developer activate the peroxide inside it- removing the natural melanin and eventually developing the dye in hair. Developer is applied with bleach and dye as bleach tends to remove the previous color from hair after which the dye would have better access deeper in the hair fibers.
Composition of Different Volumes of Hair Developers
In the market, various strengths of activators are available. Most commonly, 10, 20, 30 and 40 volumes are used as higher concentrations can lead to an increased potential of hair damage. Quantities of hydrogen peroxide determine the activator volumes. Their strengths are expressed in the form of percentages.
Equivalent strengths of commonly used developers are:
10 volume developer = 3%
20 volume developer = 6%
30 volume developer = 9%
40 volume developer = 12%
Correct Processing Time of Different Developers
The next detail to comprehend before hair dying is how long the developer needs to be left on for getting the desired shade. The recommended exposure times of different hair developer volumes vary greatly:
- 10 volume developer: 40 minutes
- 20 volume developer: 20 to 30 minutes
- 30 volume developer:15 to 30 minutes maximum
- 40 volume developer: not more than 10 to 20 minutes
The right processing times may vary depending upon the hair color you’ve, before dying. For example, developer 20 volume can lift about 2 tones in blonde hair in even 10 minutes while darker, more resistant hair need a minimum of 20 to 30 minutes for similar results.
Now the question arises is it unsafe to leave the hair developer for longer spans and does developer damage hair due to longer retention times? The answer is obviously yes. Expert stylists advise not to let hair developer stay for more than 30 minutes. Even 20 minutes is safe in most cases for different hair volumes and tones. The processing span of the activator completes in a particular time. After that, it’s not gonna make your hair lighter, rather the detrimental chemicals present in hair developer would severely affect the hair fibers besides damaging the scalp.
What would be the outcome? You’ll be left with very rough and frizzy hair, that would prone to fall.
How to Select the Most Appropriate Volume and Strength of Developer?
Now coming to the most critical step – choosing the suitable developer volume or strength for optimal results. Below is a complete guide:
10 Volume Developer:
If you’re thinking of using 10 volume developer to lighten hair, then it might not be the right choice as it doesn’t lift the base color notably, rather only deposits it in hair. It is ideal for those who want to cover grey hair with fine or medium texture or just wanna add a slight tint to their hair. It can help you change your unwanted dye by a slight tone. However, it can lift hair tone by 1 level when applied to fine hair. Developer 10 volume is used for covering hair with less than 25% greys.
With only 3% hydrogen peroxide, this accelerator is the safest among others available in stores and slightly opens the cuticle for color deposit. 10 developer with bleach can lift 1 to over 4 color levels—based on the nature of hair and bleach used.
20 Volume Developer:
This activator can help you deposit color and then lift about 1 to 2 color levels from your previous dye. It’s great for grey coverage. It provides 1 shade lift on medium and rough hair texture and 2 tones lift on the application on fine hair. 20 volume developer with bleach can boost up to 5 levels of lift on natural virgin hair. So, if you want natural blonde hair, try this concentration.
Now the concern is, does 20 developer damage hair. The answer is no. It wouldn’t be harmful if it’s not left on hair longer than its recommended processing time i.e. 30 minutes.
30 Volume Developer:
This 9% peroxide activator is great for those looking for higher color lifts. It should be used by people with healthy hair and wanting light hair dye. Due to its increased strength, it can be a bit harsh and irritating. Then does 30 developer damage hair. Yes, it can be damaging if not used cautiously or used on sensitive, rough, lighter hair.
Use 20 or developer 30 volume if you have greater than 50% grey hair and wanna cover them completely.
40 Volume Developer:
This activator can be the top pick for the ones who want deeper, high- lift dyes – without mixing with bleach. This way, the developer alone can change the hair color up to 4 tones. For fine hair textures, it offers 4 to 5 shades of lifting and about 3 to 4 tones on rough or medium textures.
But this hair developer should never be used by the ones with sensitive hair or scalps due to its high strength of about 12% hydrogen peroxide. In this case, using 20 or 10 volume developer with bleach or repeated applications of lower strength accelerator is a comparatively safer option. Don’t forget to apply large amounts of conditioner or protein serums if you’re gonna use 40 volume developer.
Apart from the developer’s strengths, the result of every activator is based on the hair texture to which it’s being applied.
Does Developer Damage Hair?
Now after knowing the basics of developer, you need to understand is developer bad for your hair or not.
Developer is safe to use if it’s used cautiously, in the right way, as recommended by expert hair stylists as this product is formulated for hair.
- However, developer can damage hair if it is used along with bleach or dye. Developer itself has mild bleaching properties and is quite safe to use unless its activation by combination with bleach or dye which can affect hair by ripping off the cuticles and penetrating inside them.
- Activators used alone have lesser hair-lightening abilities so they need to be used excessively and repeatedly. This way, they can be harmful to hair.
- Does developer damage hair if you keep it on longer? Yes, the higher retention times can pose great damage.
- If you don’t opt for its right volume or strength according to your present hair type or desired hair color, your hair will have to face fizziness apart from not getting your desired color. More the developer’s strength and volume, greater would be the possibility of resulting damage. Mostly, 20 and 30 volume developer are considered safe for all hair types.
- Does developer damage hair if it is purchased from any unknown, cheap brand? Yes, using activators from unrecognized brands containing harmful, unapproved chemicals, without testing can result in pretty serious side effects.
- If you use it on unhealthy, dry, coarse hair, it can affect them even more.
All these factors might have cleared your query i.e. does developer damage hair.
Can You Use Developer By Itself?
If you’re a person new to hair dying, you might’ve wondered what does hair developer do by itself, at least once. The developer contains hydrogen peroxide. Due to its hair lightening properties, it alone can lighten hair to some extent by removing melanin. But you shouldn’t conclude using developer on your hair without combining it with bleach or color as it’s not recommended by hair stylists at all!
The reason is developers are not made to function by themselves. When applied on its own, the results of the developer i.e. pulling apart hair cuticles and lifting hair dyes are minimal so hair damage caused by it would also be less. But don’t use it if you need instant results as it needs repeated applications for attaining deeper dyes. These multiple developer applications can in turn intensely damage the hair – eventually causing rough, brassy hair.
Developers cause mild color lifting as they contain lesser quantities of ammonia compared to that present in hair dyes. Ammonia increases the hair’s pH, activating the peroxide present in dye eventually causing the color to be penetrated deeper into the hair cortex.
Thus, for a perfect hair dye, developer, bleach and color, all need to be mixed in the right quantities.

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Pros and Cons of Using Hair Developer
Now as you know does developer damage hair or not, let’s have a look at some of its pros and cons:
Pros:
- Gives subtle results: If by mistake, you’ve dyed your hair bolder or lighter than your desired color, you can fix it by using developer- as its application would give you subtle changes .
- Causes minimal damage: Using low volume developers can relatively decrease hair damage (due to lesser cuticle opening) compared to their application with bleach to remove the previous color.
- Budget friendly: Purchasing hair developer alone is quite inexpensive than buying bleach powder and shampoo with it or getting it done by any professional stylist.
- Lifts 1 to 2 hair tones: Developer can be a good option if you wanna lift your hair shades slightly as going from blonde to medium blonde.
Cons:
- Gives lesser shade lifts: Hair developer can only lift tones slightly so its use isn’t gonna be advantageous for somebody who wanna go from darker to completely blonde hair.
- Greater risk of hair damage: If you don’t select the right volume developer or don’t consider the above-mentioned factors during its application, your hair and scalp can be affected.
- Higher exposure time can be harmful: The recommended processing time of whatever strength or volume of activator you’re using should be followed, keeping in view your desired pigment.
Summing Up
If you’re intending to dye your hair and wanna avoid damage caused by the developer, then do consider the above-mentioned instructions and factors before using the hair developer.
FAQs
No, shampoo can’t be used as a replacement for developer as both of them have dissimilar compositions and effects. Mixing hair color with a developer is inevitable for perfect results. Using shampoo in place of developer can lead to patchy dye.
A bleach bath is a process that involves diluting the bleach which is far less harmful than regular hair bleaching. It is done to lighten or color correct the messed-up hair a bit.
Bleach bath works by mixing developer, bleach and shampoo in the ratio 1:1:1 unlike the standard bleaching method involving mixing the developer and bleach in proportions 2 : 1. Bleach bath can also be done by mixing bleach with shampoo in 2:1 ratio — without developer — for avoiding any hair damage at all.