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If you’ve just brushed your teeth, you may find that your favorite food or beverage tastes less than delicious. Why does toothpaste affect the taste of delicious drinks and foods?

The culprit behind this mysterious taste alteration is sodium lauryl sulfate (SLS).

SLS is found in certain foods, cosmetic products like shampoo, cleaning products, as well as most tubes of toothpaste.

In toothpaste, sodium lauryl sulfate is an ingredient responsible for making the toothpaste foam up in your mouth. It is also the culprit behind everything tasting so weird after you brush.

In toothpaste, SLS gives you that oh-so-clean, bubbly, foamy feeling when brushing your teeth that manufacturers know makes you feel like your mouth is cleaner. That foamy feeling from SLS might feel good, but the truth is that it actually strips away the protective lining of the mouth.

Why Should You Avoid SLS?

SLS is what's commonly known as a “surfactant.” This means it lowers the surface tension between ingredients, which is why it’s used as a cleansing and foaming agent in some toothpastes to keep your teeth squeaky clean.

But besides helping your favorite toothpaste clean your teeth, surfactants like SLS also affect your tastebuds. First, SLS suppresses the receptors that pick up the sweet taste in drinks and food. This is why some foods tend to taste a little off if you’ve recently brushed your teeth. Secondly, SLS enhances bitter flavors, so sour drinks and foods taste especially bitter — yum.

In general, SLS has potential risks on overall health, as shown by research:

  • SLS is known to cause skin irritation and allergies, particularly for those with sensitive or acne-prone skin.
  • The World Health Organization (WHO) warns about the harmful effects of SLS if swallowed, including eye, lung, and respiratory irritation.
  • Even in low concentrations, chronic toxicity of SLS has been suggested.

Believe it or not, SLS is rated as a high hazard for irritation and a moderate hazard for organ toxicity by the Environmental Working Group’s Cosmetic Database. It’s pretty strong stuff, hence why it’s found in many household cleaning solutions. Yikes!

There are several good reasons to steer clear of sodium lauryl sulfate in your toothpaste and other personal hygiene products:


SLS can be an irritant, causing discomfort for some folks. If you're prone to canker sores or have sensitive oral tissues, using SLS-containing toothpaste might lead to mouth sores, dryness, or mild irritation.

Foaming Overload 

SLS is responsible for the foamy action in toothpaste. While foam might seem like a sign of cleanliness, too much can be uncomfortable. Some people find excessive foaming unpleasant and even experience a drying sensation in their mouths.

Taste Tweaks 

SLS can mess with your taste buds temporarily. After brushing, it might leave you with a metallic or bitter taste in your mouth, affecting your taste perception.

Allergies and Sensitivities 

Though relatively rare, some individuals have allergies or sensitivities to SLS. If you fall into this category, using SLS products could lead to skin rashes, itching, or other allergic reactions.

Oral Health Concerns 

While the scientific evidence isn't crystal clear, there's a debate about whether SLS can contribute to issues like canker sores and other oral health problems. To err on the safe side, some people choose to avoid SLS in their toothpaste.

Drying Effect 

SLS can also act as a drying agent. For those with dry mouth issues, this may not be ideal. Dry mouth can increase the risk of cavities and other oral health problems.

So, considering an SLS-free toothpaste might be a wise choice if you're looking out for your oral and overall well-being. It can help you sidestep these potential issues and ensure a more comfortable brushing experience.

Now, let’s zoom out to see the bigger picture. Avoiding SLS in personal care products isn't just about your mouth. It’s a resolute step towards safeguarding your overall health.

Impact on Skin and Hair

SLS is like a double trouble agent for your skin. It not only can destroy the lipid layers that keep skin supple and smooth, but it can strip natural protective barriers, too, disrupting the skin's oil and pH balance. The result? Your skin and hair can look lackluster and become more vulnerable to the harmful effects of toxins. 

Do Sulfates Like SLS Cause Canker Sores?

In a recent study, researchers found that individuals who stopped using toothpaste containing SLS reduced their canker sores over three months from a whopping 14.3 ulcers down to 5.1 ulcers. Furthermore, a study from 2012 highlighted the fact that for those who already had a pesky canker sore present, using SLS-free toothpaste decreased the pain and even the duration of their ulcers. 

As for why this harmful surfactant causes painful sores, experts believe that SLS irritates the soft and super-sensitive tissue inside your mouth and gums, removing protective layers and making them much more susceptible to canker sores.

Remember, a susceptible mouth is a vulnerable mouth, and bacteria love to cling onto teeth in vulnerable mouths, which can open Pandora’s box to a plethora of health issues. 

Your mouth is the gateway to your overall health. This means that a  vulnerable mouth increases the risk of bacterial infection in your bloodstream, which can affect you negatively in more ways than one. 

Whether you suffer from canker sores or not, switching your toothpaste to an SLS-free brand is an excellent preventive care choice. But buyer beware, some sneaky manufacturers hide SLS in their ingredients under different names. 

Here are some of the ingredients to watch out for in your toothpaste:

  • Monododecyl ester sodium salt sulfuric acid
  • Akyposal SDS
  • Sodium Dodecyl Sulfate
  • Sodium dodecyl sulphate
  • Sodium salt sulfuric acid
  • Monododecyl ester
  • Monododecyl ester
  • Sulfuric acid monododecyl ester sodium salt
  • Sulfuric acid
  • Sodium salt
  • A13-00356
  • Aquarex Methyl

Why Do Toothpaste Ingredients Matter?

So you may wonder why avoiding toxic toothpaste ingredients like SLS is so important when toothpaste isn’t in your mouth for long. 

Here’s the deal: The mouth-body connection is very real, and as we mentioned, poor oral health can contribute to many unwanted (and preventable) health conditions, such as heart disease, diabetes and even osteoporosis.

Having a happy, healthy mouth is of utmost importance because anything we put into our mouths, no matter how briefly, can significantly affect our oral and overall health. Aside from SLS, there's a whole host of other harmful ingredients in toothpaste to be cautious of, such as polyethylene glycol, which has been linked to endocrine disruption, parabens that have been associated with the development of cancers, as well as developmental and reproductive issues, and carrageenan, which can cause inflammation in the body.

So, steer clear of these to ensure you’re taking proactive steps to protect your oral health and, in turn, enhance your overall well-being.

Switch to Twice SLS-Free Toothpaste

So, now you should have a pretty good idea of what SLS in toothpaste is and why it’s an ingredient you should try to avoid. As a surfactant, SLS enhances bitter tastes and inhibits sweet ones, making everything taste bad. Additionally, SLS has been linked to poor oral health, which can lead to many overall health issues down the road.

If you find that you’re left with a funny taste in your mouth after brushing or have been struggling with canker sores and other types of irritation in your mouth, your current toothpaste could be the culprit. 

It’s time to think Twice about your toothpaste. (See, what we did there?)

Taking care of your mouth by avoiding harmful chemicals like SLS is your first line of defense in preventive care because your mouth is essentially the gateway to your overall health.

Switch to our SLS-free Oral Wellness Toothpaste for clean, high-performing ingredients that optimize your oral wellness for a healthy, bright smile and a balanced microbiome.