What Is Sodium Lauryl Sulfate?
Sodium lauryl sulfate is probably one of the most controversial ingredients in the beauty industry but is its reputation undeserved? Sodium lauryl sulfate is used in cleansing products like shampoos, cleansers and body washes as it has a unique ability to create a foam and remove oils and dirt from the skin. The controversy surrounding this ingredient has to do with that unique ability to cleanse and foam. Those who advocate for avoiding sodium lauryl sulfate or SLS argue that the ingredient strips the skin and hair of its natural oils, leaving it susceptible to irritation and sensitivity. This is partially true.
Sodium lauryl sulfate does remove the skin and hair’s natural oils in order to cleanse however this is not necessarily a bad thing and is unlikely to cause irritation or sensitivity in most skin types. Do the benefits of formulating with sodium lauryl sulfate outweigh the risks? Firstly, let’s understand why sodium lauryl sulfate is and how it is made.
Sodium lauryl sulfate is usually extracted from the fatty acids in coconut oil or palm oil and is known as a common surfactant which means that it is a great ingredient for breaking down oils and lifting dirt from the skin. Sodium lauryl sulfate can also be produced synthetically, creating less strain on environmental resources like coconut and palm oil. Synthetic manufacturing also keeps the cost down, making your products affordable. One of the main reasons sodium lauryl sulfate is so widely used is that it is a milder surfactant that other similar ingredients such as sodium lauryl ether sulfate (SLES) and ammonium lauryl sulfate (ALS). It also gives the products the lather and foam that we are so used to when cleansing.
Sodium Lauryl Sulfate
the good:Sodium lauryl sulfate is a great foaming agent and helps to lift oils and dirt from the skin, allowing them to be washed away.
the not so good:It has been linked with irritation and sensitivity in some skin types.
Who is it for?All skin types except those that have an identified allergy to it.
Synergetic ingredients:Works well with most ingredients.
Keep an eye on:Keep in mind that many brands that advertise SLS free on their products will use similar surfactants in place of SLS. So if you are wanting a gentle product or you are prone to sensitivity, low foaming products are less likely to irritate and strip.
What Are The Benefits of Sodium Laurel Sulfate?
Sodium lauryl sulfate is an effective cleansing ingredient, helping to break down oils and lift dirt allowing them to be washed away. This is why SLS’ is used in so many cleansing products such as body washes, facial cleansers, shampoos, and even toothpaste. Skincare products with this ingredient also provide a strong lather and are good cleansing options during summer, when the amount of oil secretions increases on the skin. A good facial cleanser with a surfactant like sodium laurel sulfate, or similar compounds, may be helpful to get rid of acne in such situations. However, it will not be effective on its own, as it does little to break down the sebum in already-clogged pores the way salicylic acid does.
SLS helps to improve the lather or foam of a product. This is an important element of the formulation process. Not only does the lather help to cleanse the skin but it also helps to improve the texture and sensory feel of the product. This helps the skin to feel cleaner and refreshed.
Some studies have suggested that SLS may also have mild antibacterial properties. This may help to support healing and reduce minor infections. While this is an interesting area of study the results do not yet indicate a new benefit of the ingredient. Keep a lookout for more research into this effect.
Sodium lauryl sulfate is thought to be helpful in stabilizing the product. Acting as an emulsifier the ingredient helps to keep the other ingredients in the product mixed, preventing separating or splitting. This makes the ingredient popular with manufacturers because it achieves several desired product properties with just one ingredient – thus making products somewhat cheaper. The concentration of SLS is comparatively lower in leave-on skincare products compared to the cleaning products which are designed to be washed off.
Which Types of Products Contain Sodium Lauryl Sulfate?
Sodium lauryl sulfate is mainly used in toothpaste, shampoos, soaps, and facial cleansers but can also be found in skincare products such as moisturizers, hair gel, lip balm, and hair removal creams.
Sodium Lauryl Sulfate vs. Sodium Laureth Sulfate
If you have heard of sodium lauryl sulfate you have probably come across the similar-sounding sodium laureth sulfate. The two sulfates are commonly used in skincare and cosmetic products, sometimes even together. Their similar-sounding names may confuse but you would be right in thinking that they have similar properties in skincare products. The main difference is that sodium laureth sulfate binds less to the skin which results in a reduced likelihood of irritation or sensitivity.
What Are The Side Effects of Using Sodium Lauryl Sulfate?
The main two points of contention with the use of SLS in skincare and haircare products is that they strip the natural oils and they can cause irritation.
Natural oils help to protect the skin and regulate moisture levels. Some argue that using SLS products can remove that protective barrier and cause sensitivity. This is true, using an SLS product may cause the natural oil barrier to be reduced, unfortunately these natural oils hold dirt and pollution close to the skin so cleansing is also important. The balance really lies in knowing if your skin needs a strong cleansing ingredient like SLS or if it needs something milder. Generally, if you have oily or normal skin that isn’t sensitive or irritated then SLS products are fine and are unlikely to cause irritation or dryness. However, if you have dry skin or skin that is prone to sensitivity then avoiding SLS may be a good decision.
In terms of hair care products if you have dyed, fine, or dry/textured hair then SLS containing products may not be for you either. As SLS is stripping it can strip the natural oils, dull dyed hair, and dry out dry or textured hair.
Is Sodium Lauryl Sulfate Safe?
Practical experiences and studies have shown that despite being milder than the SLES, sodium lauryl sulfate can cause skin irritation during and after the use of an SLS containing product.
The ingredient can cause itching, pain, and redness when it comes in contact with the eyes, and strong concentrations of the compound in skincare and hair care products can also cause excessive dryness. In some cases, the presence of sodium laurel sulfate in toothpaste can even lead to the development of mouth sores. Although there is little risk of bioaccumulation issues after using products with this ingredient, meaning that side effects are unlikely and not long term. However, the presence of sodium laurel sulfate in hair coloring products can dry out the hair strands, making them brittle, and difficult to repair quickly, which can become a nuisance for those with long or dry hair.
Bondi, C, Marks, J, Wroblewski, L, Raatikainen, H, Lenox, S, & Gebhardt, K, 2015. ‘Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products’, Environmental Health Insights, 9, 27–32.
CIR, 1983. ‘7 Final Report on the Safety Assessment of Sodium Lauryl Sulfate and Ammonium Lauryl Sulfate’, International Journal of Toxicology