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Bleaching Hair Side Effects: What You Need To Know

It’s common knowledge that bleaching can be damaging to the hair. I’m not here to scare you out of switching up your hair color, I just want my readers to know the bleaching hair side effects before taking this bold step.

We’ll explore just how hair bleaching works, and what its side effects on the hair are. Hopefully, this will help you to make the decision on whether to bleach your hair or not!

What Is Bleaching And How Does It Work?

Hair bleaching is a chemical process geared at lightening one’s hair color.

Generally, bleach is used to lighten the hair in a process known as oxidation in order to make your current hair pigment colorless.

Bleaching often makes use of hydrogen peroxide, a common lightening agent.

This is usually added to persulfate salts, which help speed up the process of lightening your hair.

Let’s break down this process step by step:


Your strands swell

This might be an unexpected first step, but this is actually very necessary for the process of bleaching to be successful.

The first step in the process is the swelling of your hair strands.

Lighteners such as hydrogen peroxide are alkaline agents, which have the capacity to make hair strands enlarge.

This is also why bleached hair tends to look fuller and more voluminous.

With the hair cuticles open, it becomes much easier for the lightening agent to penetrate each hair strand to do its work of lightening your hair color.

In fact, a more swollen shaft means a more successful coloring (or decolorizing) process for the hair!


Melanin is dissolved

An open cuticle means an open door for the whitening agents, or oxidative agents, to do their work!

What they do is dissolve the hair’s natural pigment, which is called melanin.

It’s this pigment that gives the hair (and also the skin) its dark color.

What the oxidative agents do is react with melanin in a process known as oxidation.

It breaks the double bonds present in melanin to eliminate its capacity to absorb light.

In doing so, melanin becomes colorless and unable to reflect the dark hair color we originally have.

However, melanin takes time to dissolve, which makes bleaching a long process.

Additionally, the longer you bleach your hair, the lighter or more colorless your hair will start to look.


Hair porosity increases

Hair porosity refers to the hair’s ability to absorb moisture.

When bleaching the hair, you’ll notice that the oxidizing agents come at different levels – 6% or 12% hydrogen peroxide, typically.

A higher volume means a faster penetration of the cortex and the dissolution of melanin.

bleaching hair side effects

This is what causes the hair to be porous.

A higher level of hydrogen peroxide concentration will make the hair more porous, as more of the chemicals get absorbed into the hair shaft.

However, it’s important to know that the hair’s natural size is not affected by bleaching.

The change in texture is simply a product of more porous hair, which gives it more volume but can also tend to make it dry out faster.


Can Bleaching Damage Your Hair?

Now, if you’re still waiting for the answer if bleaching can actually cause damage to the hair, the short answer is that, yes, it damages the hair.

As you can surmise from the explanation early on, bleaching causes a permanent change or alteration in the hair’s chemical composition, which is a recipe for hair damage.

In addition, the hair shaft’s larger opening, as a result of bleaching, can also make it more prone to damage, as well as hair drying out.

There are various side effects of bleaching the hair, both short-term and long-term, which we’ll be discussing shortly.


Bleaching Hair Side Effects

The fact that bleaching is a product of a chemical reaction already speaks volumes about the drastic changes your hair will be undergoing because of this process.

As such, it only makes sense that it has side effects on your hair, and even on you, as an individual.

Let’s break these down into short-term and long-term side effects.


Short-Term Effects Of Bleaching Hair

The following are the short-term side effects of hair bleaching:


Bleaching burns the scalp

The process of bleaching is a very harsh one, so a burning sensation is to be expected.

This is something you can protect your scalp against, though, as the burning feeling you get on your scalp before and after bleaching is dependent on a couple of factors.

First, the darker your hair is, the more bleach is needed to lighten it.

That means that people with darker hair color are more likely to feel the burn due to bleaching.

Darker hair colors might need more than one round of bleaching just to achieve their desired blonde or platinum color, actually!

The amount of hydrogen peroxide (and the level they use) is also a major factor, along with how close the bleach gets to your roots or your scalp.

So long as your bleach is near your roots, you’re bound to feel some burning, too.

To protect against this, it’s advisable not to shampoo your hair at least a day before you bleach.

Having extra oil on your scalp will definitely help protect against bleach burns.


Bleaching causes redness of the scalp

As bleach is a chemical, it’s expected that your scalp is going to be quite red during and after your bleaching procedure.

It’s good to treat this as some kind of burn and put an aloe vera ointment to help with the redness and inflammation.

In some instances, you might even have scabs on your scalps.

This isn’t a normal reaction, but it can happen.

Try not to shampoo or use other hair products for a few days in this case.


Bleaching causes itchiness of the scalp

This isn’t anything to be alarmed about – it’s usually just a side effect of the burning!

If you’re careful during the bleaching process, this shouldn’t also be a problem you’ll face.

However, if you do feel an itching sensation even weeks after bleaching, it would be best to consult a dermatologist regarding your condition.


Bleaching can cause allergic reactions

Hair dyes, as well as bleach, can cause allergic reactions due to an ingredient called paraphenylenediamine, a common allergen.

People with contact dermatitis are prone to this, as well as people with skin conditions such as eczema and psoriasis.

If you’ve had a history of these conditions, it’s advisable to avoid bleaching or dyeing your hair.

Mild cases of allergic reactions to bleaches include itching, redness, skin irritation, and swelling on the scalp, face, or neck.

Asthma is also a common allergic reaction to dyes, especially given the pungent odor they give off.

Inhaling the smell of bleach can lead to wheezing, throat discomfort, and even asthma attacks.


Bleaching can cause conjunctivitis

Your eyes are very near your scalp, so being careless in handling harsh chemicals like bleach can be detrimental when it comes in contact with other sensitive parts of the face, such as the eyes.

Conjunctivitis, also called pink eye, is an issue you might face if the bleach comes in close contact with your eyes.


Bleaching can cause discoloration

Certain areas of your scalp can appear discolored when it comes in contact with bleach.

After all, melanin is also present in these areas.

This isn’t any cause for worry, though!

With time, your scalp will return to its natural color.


Long-Term Effects Of Bleaching Hair

Let’s now look at the long-term side effects of bleaching your hair:


It dries out the hair

As mentioned earlier, bleaching can strip the moisture from your hair.

This makes your hair more porous – meaning the shaft is more open.

As a result, you’ll find that while moisture can enter easily, it can leave the hair more easily as well.

Using different chemicals on your hair tends to take a toll on your mane.

Bleaching, on top of other damaging activities such as styling and environmental damage, can inevitably dry out your hair.

Accumulated damage, especially to your hair cuticle, may make your hair unable to hold moisture, leading to dryness.


It makes the hair prone to breakage

Opening your cuticles doesn’t only pose a danger to moisture retention, it’s also a leading cause of hair damage.

Bleaching can keep opening the shaft up to the point that nothing holds it together anymore.

When this happens, the cortex becomes exposed, thereby leading to split ends and breakage in the hair.

Bleach is also a harsh chemical that can damage the hair.

Thankfully, there are products that help protect the hair from the damage bleaching can bring.

Remember to ask your hairdresser to add Olaplex to the bleach.

Olaplex is a bonding agent that helps to avoid the damage that is caused by bleaching and coloring your hair.

Overtreating or overprocessing your hair with chemicals will also cause it to look dull and break easily.

If not done correctly (for instance when bleaching is done at home), it can even break your hair enough to wash it away with water.

The sad news is that damage from bleaching is irreversible if the procedure is not done properly.

The only way to reverse the damage is to chop off your bleached hair, grow out your hair and keep it healthy.


It alters your curl pattern

Another downside is that bleaching can change your curl pattern.

This doesn’t always happen, but it can be a possibility for some people.

This is also a result of changing the hair’s porosity.

Lower porosity can certainly help enhance your curls and make your hair hold better.

Chemical processes such as bleaching and coloring your hair make it overly porous.

As a result of the high porosity, your hair is unable to hold moisture and also loses its natural curl pattern.


Creates the illusion of volume

As discussed earlier, the alkaline agents of bleach cause your hair shaft to swell and to open further.

This gives the illusion and texture of fuller hair, although the actual size or diameter of your hair isn’t really altered.

This may actually be good news to some, especially those wanting some volume for the hair.

However, if you’re not one to want your hair’s overall look to change, then this may be bad news.


It requires excessive upkeep and maintenance

This isn’t necessarily a side effect, but it can be a very inconvenient thing to contend with for people who want to bleach their hair.

Colored hair is sensitive and requires a lot of care.

You need to maintain it carefully for long periods of time.

In fact, having your hair bleached or colored really requires commitment on your end, to the point that you might need to visit the salon every now and then.

Due to the vulnerability and susceptibility of bleached hair to damage, you’ll need to buy products specifically geared toward keeping it healthy and strong.

Otherwise, you’ll end up with dry, lifeless hair, which we definitely wouldn’t like!

Related Post: How To Fix Bleached Hair Breakage



Sometimes it’s just hard not to entertain the idea of sporting a new hair color.

After all, who doesn’t want to experience the fun of seeing their hair in a different shade, far from the usual color you see in the mirror every day?

However, it’s also scary to take that leap of faith and just color your hair. 

At the back of our minds, we have to think about bleaching hair side effects.

The thing is, bleaching is a big decision that you have to mull over carefully if you’re looking to do it.

While bleaching and coloring your hair might look very pretty, refreshing, and unique, it’s also good to consider the damage that your hair will be taking because of it.

Nonetheless, these side effects may be present, but they’re not completely unavoidable nor irreversible.

With time and proper maintenance, your hair will surely be as healthy as you want it to be.

Not to mention, the experience of having your hair colored and seeing the results is a wonderful experience in itself!

The final decision is of course, up to you.

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