While sodium lauryl sulfate (SLS) is not inherently "bad" in toothpaste, many people experience adverse reactions to it, such as oral irritation, allergic reactions, and canker sores.

In the past, SLS has been a common toothpaste ingredient that helped remove debris and stains from the teeth due to its detergent properties. However, due the potential negative long-term effects of SLS on oral health, SLS free toothpastes have emerged as a safe and gentle substitute for it.

In this article, I'll explain everything you need to know about SLS and whether or not it's bad in toothpaste.

What is sodium lauryl sulfate?

Sodium lauryl sulfate, also known as SLS, is a detergent, surfactant compound, and foaming agent found in many household cleaning products and personal care products, including:

• toothpaste

• shampoo

• shaving cream

• and body wash.

Its primary function is to create foam and lather, which helps to remove dirt, oil, and debris from the surface being cleaned. Sodium lauryl sulphate is commonly found along side of similar ingredients such as hydrogen lauryl sulfate.

In toothpaste, SLS helps your toothpaste disperse evenly throughout the mouth and reach areas that may be difficult to access. However, SLS can also be quite harsh as it has the potential to strip away oral mucosa, the protective layer of saliva that coats the gums and oral tissues.

This can lead to dryness and irritation in the oral cavity, especially for individuals with sensitive gums or a predisposition to oral sensitivity. For this reason, many people are turning to SLS free toothpastes for a safer, more gentle clean.

Why does SLS do in toothpaste?

SLS is commonly included in toothpaste for its surfactant properties, which help create foam and lather. This foaming action helps you distribute toothpaste throughout your mouth during brushing which allows it to reach areas that might otherwise be difficult to access.

Additionally, SLS enhances the cleaning efficacy of toothpaste by effectively removing debris, food particles, and plaque from the teeth and gums.

While toothpaste is generally safe and SLS can be beneficial in toothpaste, some people may experience allergic reactions or increased sensitivity to SLS, manifesting as recurrent aphthous ulcers, canker sores, or a burning sensation in the mouth. Therefore, there is ongoing debate and research regarding its potential adverse effects on oral health.

Thankfully, as technology has progressed, we now have newer, more gentle surfactants that can be found in SLS free toothpastes as compared to SLS containing toothpaste.

Risks of SLS in Toothpaste

The risks associated with sodium lauryl sulfate (SLS) in toothpaste primarily revolve around its potential to cause irritation and sensitivity in some individuals. SLS is a surfactant that can strip away the protective layer of saliva on the gums, leading to dryness and irritation.

Some people may experience allergic reactions or increased sensitivity to SLS, manifesting as mouth ulcers, canker sores, or a burning sensation in the mouth.

Let's walk through some of the main risks of SLS toothpaste.

Oral Irritation

Oral irritation is a common concern associated with sodium lauryl sulfate (SLS) in toothpaste. SLS is a surfactant, which means it has detergent-like properties that allow it to create foam and facilitate the distribution of toothpaste ingredients. However, these same properties can also strip away the protective layer of saliva on the gums, leading to dryness and irritation.

Furthermore, SLS can disrupt the delicate balance of your oral biome, potentially contributing to oral health issues such as gum inflammation or infection. This disruption of the oral microbiome, coupled with the abrasive nature of SLS, can exacerbate oral irritation and discomfort.

Dry Mouth

Dry mouth, or xerostomia, can be a potential risk associated with sodium lauryl sulfate in toothpaste.

SLS is a surfactant that creates foam and aids in the distribution of toothpaste ingredients, but it can also strip away the protective layer of saliva in the mouth. Saliva plays a crucial role in maintaining oral health by lubricating the oral tissues, buffering acids, and washing away food particles and bacteria. When SLS disrupts this protective saliva layer, it can lead to dry mouth.

For individuals already predisposed to dry mouth, such as those taking medications that reduce saliva production or individuals with certain medical conditions, switching to SLS free toothpastes may alleviate discomfort.

Allergic Reactions

Some individuals may experience allergic reactions upon exposure to SLS in toothpaste. These reactions occur when the body's immune system overreacts to the presence of SLS, triggering inflammatory responses throughout the body. For those people with a history of allergic reactions or sensitive skin, switching to fluoride free toothpaste without SLS can reduce risk.

Increased Risk of Aphthous Ulcers

The presence of sodium lauryl sulfate (SLS) in toothpaste has been associated with an increased risk of developing aphthous ulcers, also known as canker sores, for some individuals. Aphthous ulcers are painful sores that can form on the inner lining of the mouth, including the gums, tongue, and inner cheeks. SLS may exacerbate the occurrence or severity of these ulcers due to its potential to disrupt the delicate oral mucosa, leading to tissue irritation and inflammation.

Taste Alteration

SLS is a surfactant that creates the foaming action commonly observed when brushing teeth. However, this surfactant may also interfere with taste receptors in the mouth, leading to a temporary change in taste perception. Some people may report experiencing a bitter or metallic taste after using toothpaste containing SLS, which can linger for a short period following brushing.

Does SLS cause canker sores?

Yes, SLS has been associated with an increase in the frequency and severity of canker sores.

Experts suggest that SLS may potentially contribute to the formation of canker sores by causing irritation or disruption to the delicate tissues inside the mouth. SLS is known to act as a surfactant, which can strip away the protective layer of saliva on the gums, leading to dryness and irritation.

This irritation may create an environment conducive to the development of canker sores, particularly in individuals who are predisposed to oral sensitivities or have a history of recurrent aphthous ulcers.

However, I should note that the evidence linking SLS directly to the onset or exacerbation of canker sores is not definitive, and individual responses to SLS may vary.

Do I need SLS in toothpaste?

No, you do not need SLS in toothpaste. While SLS serves as a foaming agent and helps distribute toothpaste ingredients, its presence is not essential for effective oral hygiene. In fact, many people choose to avoid SLS due to concerns about potential side effects such as oral irritation, dry mouth, or allergic reactions.

Other surfactants found in toothpaste include, but are not limited to, sodium dodecyl sulfate and anionic surfactants derived from coconut oil.

Are SLS-based toothpaste safe for everyday use?

SLS-based toothpastes, containing sodium lauryl sulfate (SLS) as a foaming agent, are generally considered safe for daily use by most people.

However, some studies suggest that SLS may cause irritation for those with sensitive oral tissues, leading to mouth ulcers or canker sores in some cases. Also, research has found that individuals prone to ulcers experienced fewer outbreaks when switching to SLS-free toothpaste. 

Additionally, SLS can cause dryness in the mouth, possibly aggravating issues like bad breath. 

For most users, however, SLS is safe with no major long-term effects. If you have sensitive oral tissues or frequent sores, switching to an SLS-free toothpaste may help.

Alternatives to SLS in toothpaste

If you're looking for alternatives to SLS in toothpaste, there are several options available that are gentler on sensitive mouths. 

One of the best alternatives is SLS-free toothpaste containing nano-hydroxyapatite (n-HAp), a mineral that helps remineralize and strengthen teeth without the irritation SLS can cause. 

Studies suggest that nano-hydroxyapatite is effective at repairing enamel and reducing sensitivity. Other alternatives to SLS include natural ingredients like aloe vera, coconut oil, or xylitol, which also help clean teeth without causing dryness or irritation. 

Therefore, for those with sensitive gums or frequent canker sores, choosing an SLS-free toothpaste can offer a safer, more comfortable experience for everyday use.

Should I use SLS free toothpaste?

Yes, you should use SLS free toothpaste if you prefer to avoid SLS due to concerns about potential side effects such as oral irritation, dry mouth, or allergic reactions. Opting for SLS-free toothpaste may be beneficial for individuals who experience discomfort or adverse reactions when using products containing SLS.

Summary: What's SLS in toothpaste?

Sodium lauryl sulfate (SLS) is a toothpaste ingredient used to create that lovely, foamy lather that we all know and love. It's a detergent agent that helps to remove debris and stains from the teeth, contributing to the cleaning action of toothpaste.

However, many individuals may be sensitive to SLS, experiencing oral irritation or other adverse reactions. For this reason, SLS is considered by many as an ingredient to avoid in toothpaste.

These negative reactions have led to the rise of SLS free toothpaste as a safe and gentle alternative to SLS-containing toothpastes.

Frequently Asked Questions

Should I avoid SLS in toothpaste?

You might want to avoid sodium lauryl sulfate (SLS) in toothpaste due to concerns about its potential adverse effects on oral health. SLS is a surfactant commonly used in toothpaste to create foam and aid in the distribution of ingredients, but it can strip away the protective layer of saliva on the gums, leading to dryness and irritation. Additionally, SLS has been associated with oral irritation, increased sensitivity, and allergic reactions in some individuals, which can manifest as mouth ulcers, canker sores, or a burning sensation in the mouth.

What does sodium lauryl sulfate do to teeth?

Sodium Lauryl Sulfate (SLS) in toothpaste acts as a surfactant and foaming agent, creating the characteristic lather that aids in the removal of debris and stains from the teeth. It works by lowering the surface tension of water, allowing it to spread more easily and penetrate between teeth for thorough cleaning. Additionally, SLS can help to solubilize other ingredients in toothpaste, ensuring they are evenly distributed throughout the oral cavity during brushing.

Is SLS cancerous?

There is no conclusive evidence to suggest that sodium lauryl sulfate (SLS) causes cancer when used in toothpaste. However, some people have raised concerns about its potential to interact with other compounds and form nitrosamines, which are known carcinogens. While the risk of cancer from SLS in toothpaste is considered low, individuals with specific sensitivities or concerns may choose to opt for SLS-free alternatives to minimize potential risks.

Why is SLS harmful?

Sodium lauryl sulfate (SLS) is considered harmful due to its association with several potential side effects, including oral irritation, dryness, and increased sensitivity. It can strip away the protective layer of saliva on the gums, leading to dryness and irritation, and may exacerbate existing conditions such as canker sores or mouth ulcers. Furthermore, some individuals may experience allergic reactions or heightened sensitivity to SLS, manifesting as burning sensations or itching in the mouth. While SLS is generally regarded as safe for use in toothpaste by regulatory agencies, concerns persist about its potential adverse effects on oral health, particularly for those with sensitivities or pre-existing conditions.

Should you avoid SLS?

Yes, you may want to avoid SLS due to its potential for causing adverse side effects. While SLS is generally considered safe for most people and provides effective cleaning properties, some individuals may experience oral irritation or sensitivity to this ingredient. If you have a history of adverse reactions to SLS or prefer to use products with gentler formulations, opting for SLS-free toothpaste may be a suitable choice.