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What Is the Ingredient in Shampoo That Causes Hair Loss?

You’ve probably always heard that certain chemicals can be bad for your hair. But what is the ingredient in shampoo that causes hair loss? Read on to find out what you really need to know about your daily shampoo.

What Is the Ingredient in Shampoo That Causes Hair Loss?

Ingredients helping answer what is the ingredient in shampoo that causes hair loss

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When you choose a new shampoo, you might read over the label and check out the benefits the shampoo offers. Then, you’ll likely pick up the matching conditioner and be on your way.

But what happens if your shampoo’s label is hiding something that could actually do your hair more harm than good?

The ingredient list on a shampoo bottle is often filled with long, complex names that many of us might struggle to understand without a solid understanding of chemistry.

But based on the benefits the bottle lists, we might also think it’s safe to assume that the ingredients that cause those benefits are perfectly safe to use. However, that may not always be the case.

In some cases, certain ingredients could actually do the complete opposite of what the shampoo claims to do. There are certain chemicals in some shampoos that have reportedly caused a user’s hair to break, fray, or even fall out.

The worst part? There’s actually no single ingredient that’s scientifically proven to make your hair fall out on its own. Instead, there’s a list of them that fall into a few specific categories. These include:

  • Preservatives
  • Irritants
  • Emulsifiers

So, what do each of these groups of ingredients do? And most importantly, how do they work together to contribute to hair loss? Let’s discuss.

1. Preservatives

Most shampoo companies will include preservatives in their shampoo formulas that will prevent them from spoiling.

In addition, these preservatives help prevent bacteria and mold growth, which helps extend the shelf life of your shampoo. If you’re the kind of person who goes a few days without giving your hair a scrub, you’ll understand the importance of a long shelf life.


Shampoo manufacturers often add a formaldehyde-releaser called DMDM hydantoin to shampoo to act as a preservative. It’s an antimicrobial compound that helps keep bacteria from forming in the shampoo.

Unfortunately, there are a number of risks when it comes to formaldehyde exposure, including allergic reactions, rashes, and other skin irritations.

Although hair loss isn’t considered a direct side effect of DMDM hydantoin exposure, skin irritation caused by formaldehyde could lead to hair loss. In addition, the level of formaldehyde in most shampoos is low enough that the risk of formaldehyde alone, leading to hair loss is minimal.

That said, when combined with other ingredients, formaldehyde could play a contributing factor in hair loss. Unfortunately, this is the case with most of the ingredients listed here.


Parabens are another ingredient that can cause skin irritation and disrupt the hormones that help keep your hair healthy. As with formaldehyde, the skin irritation that the parabens cause may lead to hair loss, especially when combined with other ingredients that can irritate your hair and scalp. 

Another major cause of hair loss is a hormonal disruption. Since some evidence shows parabens may cause hormone imbalances, it stands to reason they can also lead to hair loss. You’ll typically see parabens listed as methylparaben or propylparaben. 

2. Irritants

Shampoos often contain a number of irritants that can be harmful to your scalp and hair.

If you’ve ever shampooed your hair and ended up with an itchy scalp, you likely had a reaction to an irritant in the shampoo. The two most common irritants you’ll find in shampoo are fragrances and dyes.


Most shampoos, conditioners, and soaps contain some type of fragrance. A nice scent is one of the main reasons many people choose one shampoo over another.

However, certain fragrances can be very damaging to your hair, which is why you should avoid them. Some fragrances come from natural sources.

For example, you can find shampoos made with peppermint, eucalyptus, lemongrass, or other essential oils that smell lovely but aren’t filled with chemicals. Unless you have an allergy to a natural fragrance, it’s unlikely to cause any type of harm. 

The shampoos you should avoid are those containing artificial fragrances. These fragrances can lead to scalp, skin, and eye irritation, which can also contribute to hair loss. 

Another reason to avoid artificial fragrances is that there’s no FDA requirement for companies to disclose their fragrance’s ingredients. Simply stating “fragrance” on the bottle is sufficient, even though it doesn’t give you any information on what the fragrance actually contains. 


Most shampoos contain some type of dye. These dyes can give your shampoo a vibrant color, a pearly appearance, or a shimmery look. However, dyes and other artificial colors can be pretty damaging to your hair, especially if you’re sensitive to the ingredients. 

More than five dozen color additives are approved under the Food, Drug, & Cosmetic Act. However, most of these will simply appear on a label as FD&C, followed by a color.

As with fragrance, there’s no legal requirement for a manufacturer to list the ingredients that make up a dye. Many artificial dyes can irritate your skin, dry out your hair, or cause other damage.

Each of these things can lead to hair loss, which is why choosing a dye-free shampoo is a good choice if you want to try and prevent hair loss. Just remember that there’s usually no reason for dye in shampoo aside from aesthetic purposes. 


Phthalates are a type of chemical often found in products with a gel-like consistency, such as shampoo, hairspray, or hair gel. They’re a popular additive to shampoos because they add a pleasant scent.

But, unfortunately, they’re also very bad for you. Just like parabens, phthalates are considered hormone disruptors. Since your hormones play a significant role in hair growth, it stands to reason that phthalates can lead to damaged or weakened hair.

Between damaging your hair and irritating your scalp, it’s essential to avoid shampoos and other hair products that contain phthalates because they can contribute to hair loss.

3. Emulsifiers

A key ingredient in shampoo is an emulsifier, which is the additive that gives your shampoo that nice, thick lather. There are several kinds of emulsifiers, but the most common are sodium lauryl sulfate, sodium chloride, polyethylene glycol, and DEA.

Sodium Lauryl Sulfate

Sodium lauryl sulfate, or SLS, is a common emulsifier in shampoo. It’s excellent at binding to grease and dirt, which is how it helps get your hair and scalp so clean.

This detergent removes all of the grime from your hair and washes it away. However, it still leaves a residue behind even once it’s gone. SLS residue can be very irritating to the skin on your scalp.

In addition, as the SLS continues to dry out your scalp, it also dries out your hair. The combination of these two side effects can lead to hair loss that may or may not be permanent.

Sodium Chloride

Also known as common table salt, sodium chloride is often used as a thickener in shampoos. It works alongside emulsifiers such as sodium lauryl sulfate to help create a thick, creamy lather.

Unfortunately, even though sodium chloride is safe on its own, that’s generally only true if it’s in small doses. Salt is a desiccant. In other words, it’s excellent at removing moisture from something.

It’s why it’s so important to keep your body’s sodium levels stable and why it’s so dangerous to consume saltwater. So, if you use a shampoo with high amounts of sodium chloride, you risk drying out your scalp, which may cause your hair to fall out.

Polyethylene Glycol

Polyethylene glycol sometimes referred to as polyoxyethylene or polyethylene, is another thickener similar to sodium chloride that you might find in shampoos. It works with other emulsifiers to create a thick foam that’s effective at stripping dirt and grime from your hair. 

However, polyethylene glycol can act as a desiccant. When it cleans the grime from your hair, it also strips away the natural oils on the hair and scalp.

These oils are essential to hair strength, so when you regularly wash them off your hair and scalp, your hair can turn brittle. Over time, that brittleness combined with your scalp’s dryness may lead to hair loss. 


Diethanolamine, or DEA, is an emulsifier that helps the water-soluble and oil-soluble ingredients in your shampoo work together to remove the dirt and grease from your hair.

But unfortunately, DEA can damage the natural proteins that make your hair strong. Keratin is a protein in your hair that gives it strength, sleekness, and shine. It forms a protective shield around each strand of hair to keep it from becoming damaged.

Unfortunately, DEA can strip that keratin away over time, leaving your hair susceptible to breakage. Fortunately, you can remedy the loss of keratin by getting a keratin treatment at your salon.

Frequently Asked Questions

We'll show you what ingredient in shampoo causes hair loss


There’s so much to know about how certain shampoo ingredients contribute to hair loss. Here are a few questions that expand on some of the above points.

Can Sulfate-Free Shampoo Cause Hair Loss?

Sulfate-free shampoos don’t cause hair loss. In fact, they can do quite the opposite. Shampoos that are free of sulfates can provide similar cleaning power without the drying effect of chemicals such as sodium lauryl sulfate.

What Is DMDM Hydantoin Hair Loss?

DMDM is a chemical that many manufacturers have included in their shampoo formulas. DMDM hydantoin hair loss is the hair loss that may be attributed to using shampoos containing this chemical.

Which Product Can Stop Hair Falling Out?

There are many products that can help stop hair fall or hair loss. Strengthening hair masks, peptide serums, biotin supplements, and products that contain minoxidil are all options if you want to regrow your hair and prevent future hair loss. 

How Can I Stop Hair Fall Immediately?

Although there’s no way to stop hair loss immediately, there are steps you can take to slow it down and prevent it from getting worse.

For example, you could include more protein in your diet, drink lots of water, use a vitamin supplement that targets hair, and look into products containing minoxidil.

Do Parabens Cause Hair Loss?

On their own, parabens haven’t been proven to cause hair loss. However, over time, they can be very irritating to your scalp, which can ultimately lead to hair damage and loss.

So, What Is the Ingredient in Shampoo That Causes Hair Loss?

Although it would be nice if there was just one ingredient you could avoid to keep your hair from falling out, that’s not quite the case.

Parabens, sulfates, and irritants such as fragrances can each contribute to hair loss. To minimize the amount of hair you lose during washing, be sure to avoid all shampoos that contain those ingredients. 

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