Have you ever tried leaving conditioner in your hair overnight? Many people are under the impression that this is a good idea, but there is some debate about how good it actually is to do this to your hair.
This has become an area of great confusion for many people and I get asked this question all the time at my beauty parlor. The best way to find out whether it’s a good idea to do this is to understand what happens if you leave conditioner in your hair overnight.
Here, I’m going to dig out the facts for you so that you can learn some of the science behind what happens to your hair when you leave conditioner in it. This will help you decide whether or not you want to leave it in your hair overnight or re-think your bedtime routine.
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What Makes Your Hair Shine?

It’s a pretty well-known fact that conditioner is primarily used to make your hairy shiny. It does this by keeping the hair shaft coated in chemicals that simulate the effect of keratin, which then fills in the broken and damaged parts of the shafts. This is what makes them shiny and able to reflect light in a mirror-like manner.
When the shafts of your hair get exposed to dust and pollution, it becomes damaged. Your hair can have several fractured bits of protein, which exposes the rough and dull layers of the shaft, thus making your hair look dull.
By keeping the shaft coated in a protein-rich chemicals, it can add an ad hoc layer of protein, thus mimicking the shine of natural hair for several hours. In fact, a small amount of conditioner can be used to keep your hair protected all day long and make it appear shiny.
But, is it bad to leave conditioner applied on your hair overnight?
Long-Term Conditioning is bad for Your Hair

It turns out that almost most of the time conditioner will not cause any significant harm to your hair by being left on your hair for long hours. However, the problems may occur if you keep it in contact with your hair several times, especially if you make a habit of leaving it overnight for many days.
The main problem that can occur is that your scalp may end up absorbing the ingredients. This may cause harm to your hair because of the ingredients in the conditioner. So, what is a typical conditioner composed of?
Composition of the Common Conditioner

Let’s take a look at some of the standard ingredients commonly found in popular hair conditioning brands, such as Pantene.
These conditioners contain chemicals such as Sodium Laureth Sulfate, Sodium Chloride, Parfum, Sodium Xylenesulfonate, Cocamide MEA, Tetrasodium EDTA, Benzyl Salicylate, Fumaric Acid, Citric Acid, and many others.
These are all ingredients that you wouldn’t dare ingest. They’re each dangerous and harmful in their own ways. When you leave conditioner in your hair, these chemicals get absorbed through your scalp, which is essentially a layer of skin and then enter your bloodstream.
It is understood that the amount of chemicals that get absorbed by the skin is far less compared to the amount that enters your bloodstream if you were to orally ingest the conditioner.
But, consider this: if you leave conditioner on your scalp for long hours overnight throughout the year, it would absorb a lot more of those chemicals, and that is a scary thought.
Can Conditioner Cause Hair Fall?

Although it doesn’t cause much hair fall compared to the leading causes of hair fall, which are dust and pollution, it can do permanent damage to your scalp. The roots of your hair may become weakened, making it prone to being easily damaged by the plethora of dust and pollution that is out there.
For instance, if you keep leaving conditioner on your hair unwashed for hours, after a few years of this practice, the shaft will be permanently damaged. So the next time you dye your hair, it will seep through the shaft and go all the way down to the roots. This is one of the leading causes of hair fall.
So you can see that while it is not directly involved in hair loss, it can leave the protective system of your hair damaged, thereby leaving it exposed to the plethora of things that can easily cause hair loss.
- Do Not Leave the Rinse-out Conditioner Overnight
You need to keep in mind that conditioners that were made to be rinsed out in the shower are made with powerful chemicals that make hair softer in a short period of time. Using a conditioner that has heavy silicone chemicals is not ideal for the hair.
Furthermore, conditioners that contain protein have been proven to cause itchiness and irritation in some people. But the most compelling case against the arbitrary use of conditioners as a hair pack is that conditioners can lead to build up.
Many conditioners are heavily laden with positively charged ions in a gel-like solution, whereas most shampoos have negatively charged ions in them. These charges can interact, causing a build-up of chemicals against the shaft of the hair, which can lead to irreparable damage.
Therefore, it is imperative to use conditioner judiciously and not leave it in your hair for several hours at a stretch.
The Reason Most People Do It

It turns out that most people leave conditioner in their hair overnight because they think that this enables them to seal the moisture around the shaft. They also think this will make their hair appear soft and light. Not all of this is true.
Compare hair with fingernails as they are both made of keratin. It turns out that if you leave a nail in water it will absorb the moisture and it will become softer in texture.
But, if you leave it long enough, it will eventually soften up in a way that threatens its structural integrity vis-à-vis the skin and other tissues involved in keeping the nail attached to the body.
This leads to the nail becoming easy to break away. It can be safely assumed that the human hair behaves in a similar way and becomes vulnerable to breakage upon the exposure to excess moisture. Therefore, keeping your hair on a deep conditioning regime can eventually lead to its breakage.
How To Use Conditioner After Shampoo | Healthy Hair Tips
The Conclusion: Avoid Overnight Conditioning
Deep conditioning with conditioner that is meant to be rinsed out immediately is not good for your hair. When you leave this conditioner on your scalp for long periods of time, it can and will lead to eventual hair fall and damage. This is not a risk not worth taking.
Here are some useful tips to keep your hair conditioned without damage:
- Try not to put the conditioner directly on the scalp. It is meant to be applied on the ends.
- Read the list of ingredients that are contained in your shampoo. Try and avoid the ones that contain silicones.
- Pick a product that doesn’t have too many synthesized proteins.
- Be sure to rinse your hair entirely after conditioning.
- Try and use a moisturizing shampoo itself which will do half the job of the conditioner.
Finally, tell me about your personal experiences regarding what happens if you leave conditioner in your hair overnight. What differences did you note in your hair after following this method? Do you have any questions for me? I’m always happy to hear from you.
After several rounds of chemo and radiation, my hair is extremely sparse and thin. Where exposed to radiation, there is no hair at all. After nearly ten years, it has been challenging to make my hair appear near-normal. I have tried leaving conditioner in from shampoo to shampoo and eventually I have noticed small bumps appearing on my scalp. After reading this article, I will stop using conditioner immediately and begin rinsing my hair thoroughly. Hopefully, my scalp will return to normal.
I have really curly blonde hair and seem to need a leave in conditioner every day. .. applied like a mist. Is there a good product for me that won’t hurt my hair. I am 70 and am distressed that my hair is thinner than before.
I left some heat defence leave in conditioner in my hair for 3 days now I have big lumps on my scalp and it hurts really bad ,they keep coming up but there is no discharge except for a lil blood , what can I do to fix this