Sodium lauryl sulfate (SLS) is a surfactant commonly found in toothpastes, soaps, shampoos, and cleaning products.
Most people have no issue when they come in contact with SLS-containing products. However, strong concentrations of SLS can cause side effects, such as skin, mouth, or eye irritation.
SLS is a common ingredient in many everyday cleaning products. While it’s generally safe when properly formulated, it can still irritate some people—especially at higher concentrations or with prolonged exposure.
Key points about SLS and skin irritation:
- Frequency of exposure: Most people come into contact with SLS at least once or twice per week through cleaning products.
- Formulation matters: Well-formulated products often include ingredients that reduce the risk of irritation.
- Concentration threshold: SLS levels above 2% are more likely to irritate skin.
- Mechanism of irritation: SLS removes oil and water from the skin, contributing to dryness and inflammation.
- Common symptoms Include Redness, dryness, scaling, itching, and peeling.
- Body-area differences: Some areas (like the back) are more prone to irritation than others (like the arms).
- Skin tone considerations: Individuals with lighter skin tones may experience more pronounced reactions.
- Who should be cautious: Those with sensitive or irritable skin, or conditions like rosacea or psoriasis.
SLS is commonly found in toothpaste, where it creates the foaming action during brushing. While generally safe, it can cause irritation in and around the mouth for some people.
Key points about SLS and oral irritation:
- Where it’s found: Many toothpastes use SLS for cleansing and foaming.
- How irritation occurs: SLS can dilute and disrupt the mouth’s protective mucous membrane, leading to irritation of the gums and tissues.
- Impact on healing: Research suggests SLS may slow the healing of oral wounds.
- Canker sore risk: SLS may increase the likelihood of aphthous ulcers (canker sores), especially in those prone to them.
- Provider recommendations: People with frequent canker sores may be advised to use SLS-free oral care products.
- Need for more research: The full effects of SLS on oral tissue are still being studied.
High concentrations of SLS may irritate the eyes, although most everyday products contain levels far below those associated with serious effects.
Key points about SLS and eye irritation:
- Low-concentration safety: Animal studies indicate that SLS levels below 0.1% are generally non-irritating to the eyes.
- Research gap: Human studies are still needed to fully understand eye-related risks.
- Effects of high exposure: Older research links high concentrations of SLS to severe eye damage, delayed healing, cataracts, and even potential blindness.
Real-world relevance: Such high concentrations are rarely present in typical consumer products containing SLS.
SLS can be found in a variety of products, including:
- Health and beauty products, like toothpaste, mouthwash, shampoo, conditioner, bath products, shaving cream, makeup remover, foundation, hand soap, bath wash, lotions, and creams
- Laundry products, like detergent (powder and liquid)
- Cleaning products, like soap, dishwashing detergent, and multi-purpose cleaners
The concentration of SLS found in cleaning products typically ranges from 1% to 30%. In cosmetic products, the concentration typically ranges from 0.01% to 50%. Higher concentrations may be found in industrial products, like floor cleaners and car wash products.
SLS may also be an ingredient found in medications. The product helps turn drug powder into a stable tablet and can also aid in dissolving medicines once they are swallowed.
Read product ingredient labels to see if SLS is found in the product. If you believe you are using a product with SLS that is causing side effects, stop using the product immediately and talk with your healthcare provider.
