Toothpaste that is free of sodium lauryl sulfate, or SLS, is less likely to irritate sensitive skin and worsen skin problems. Studies have also shown that regular brushing with SLS-free toothpaste decreases the likelihood of developing canker sores. Other studies have also suggested that toothpaste containing sulfates decreases the amount of alkali-soluble fluoride deposited on the enamel, which weakens the protection.
Sodium lauryl sulfate is used to thicken toothpaste and help it foam up to dissolve dental plaque more efficiently. It also helps lower the manufacturing cost of toothpaste. It is present in shampoos, body washes, laundry detergents and more.
The EWG Cosmetics Database classifies it as a moderate hazard, with links to eye and skin irritation, organ toxicity and possible cell mutations. However, critics of these studies point out that sodium lauryl sulfate is not generally consumed in pure forms or applied directly to the eyes in large quantities, thus distorting the results of the study.
Consuming sodium lauryl sulfate leads to nausea and diarrhea. It is present in some laxatives as an active ingredient. Although few people set out to eat their toothpaste and shampoo, studies have demonstrated that toxins absorbed through the skin and transported into the body via hair follicles can be deadlier than those ingested.