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Do You Really Need SLS-Free Shampoo?

by Guy McCardle

January 30, 2012

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Donate Disclaimer: You are about to read a shampoo article written by a bald man. That doesn’t invalidate anything I have to day, I’m just letting you know in the name of full disclosure. Heaven forbid someone gets upset in the comments section and lashes out saying, “What does he know. He apparently hasn’t needed shampoo in years”.

On one of my daily internet information mining sessions I came across ads for SLS-free shampoo. Now, anytime I read about “______ - free” anything it raises a big red skeptical flag. Gluten-free comes immediately to mind. Next comes fat-free, sugar-free, PABA-free and on and on ad infinitum. Ironically, when a product has the word “free” in the title it usually costs more, as if the absence of something gives it a greater value. We Americans are suckers for this kind of stuff. Just for the record, you can buy gluten-free shampoo if you are so inclined.

Just what is SLS-free shampoo? Well, SLS is short for sodium lauryl sulfate- an inexpensive chemical added to shampoos to generate huge amounts of bubbles and lots of lather. It can also be found in carpet cleaners, engine degreasers and toilet bowel cleaners, among other household cleaning products. This doesn’t necessarily mean it is intrinsically bad. I mean, the sodium chloride I’m sprinkling on my yummy popcorn is chemically the same stuff that those big trucks spray all over icy roads here in the Northeast during the winter.

Technically, SLS is a surfactant; the chemical portion of the cleaner that sticks to the surface of the items and cleans it. Each surfactant molecule has a hydrophilic (water-loving) head that is attracted to water molecules AND a hydrophobic (water-hating) tail that repels water and simultaneously attaches itself to oil and grease in dirt. These opposing forces loosen the dirt and suspend it in the water. The mechanical agitation of washing your hair helps pull the dirt free allowing you to rinse it down the drain. As you might imagine, surfactants are an extremely important component of shampoos. SLS is super cheap besides the fact that is an efficient surfactant. That is why it has been added to shampoos for years and years. Another reason SLS is so common in shampoos is what I like to call the lather factor. It makes lots and lots of lather. Advertising through the years has taught us that more lather is supposed to be a good thing.

Please allow me to digress for a paragraph or so to talk about the “no poo” movement. It is thankfully not what first pops into one’s mind. Well, my mind anyway. What if we just didn’t use shampoo at all? The “no poo” movement consists of people rejecting the societal norm of daily or almost daily shampoo use. I suppose this makes me one of “them”. Some fellow adherents of the movement use baking soda or vinegar to wash their hair. Some use nothing but warm water. The “no poo” crowd asserts that shampooing every day is a fairly modern convention. Around the turn of the last century, shampoo was only used a few times a year. After the Farrah Fawcett days of the 1970s, shampoo use really took off and now literally thousands of brands are available to the consumer. Using shampoo on a daily basis removes sebum, the oil naturally produced by the scalp. This causes the sebaceous glands to produce oil at a higher rate, to compensate for what is lost during shampooing. According to some dermatologists, a gradual reduction in shampoo use will cause the sebum glands to excrete at a slower rate, resulting in less grease in the scalp.

Enough about the no-poo people, let’s assume you are the type who wants and needs a daily shampoo. Are there any medical reasons not to use shampoos containing SLS? Well…yes, if you are hypersensitive to it…but that is just common sense. If you use the product as directed (lather, rinse, repeat) keep the stuff out of your eyes as much as possible, and don’t swallow it you should be just fine. Back in the late ‘90s a rumor was going around the internet stating that SLS caused cancer. This is just patently false. Three different agencies, the Occupational Safety and Health Administration (OSHA), the National Toxicology Program (NTP) and the International Agency for Research on Cancer (IARC) have all stated that SLS is non-carcinogenic. If you feel that you really need one more thing to worry about, consider MIT. Methylisothiazolinone, or MIT, is an ingredient used in many commercial shampoos. MIT and its closely related analog, chloromethylisothiazolinone or CMIT, affect the ability of young or developing neurons to grow axons and dendrites in tissue culture. Some studies have shown MIT to be allergenic and cytotoxic, and this has led to some concern over its use.

According to the experts at Melbourne Dermatology, ..."SLS cleaners are safe and generally preferable to soaps... irrational and financially- motivated online scare mongering about this ingredient is rife. The absence of SLS does not automatically indicate that one product is more suitable than another." As is the case with many subjects this writer looks at skeptically, there is some truth to the negative hype. In this case it is the statement that using products containing SLS can be detrimental to the skin and hair. This has nothing to do with the SLS itself, however. The majority of cleansers containing SLS are a a poor match for skin, primarily due to their relatively high alkalinity and tendency to foam heavily. Apparently lots of foamy bubbles may be appealing to the eye, but they do not aid in the cleaning process. A low or no-foaming method of cleansing the scalp improves the hair's volume by desincrusting the follicles of the same sebum and dead cells commonplace shampoos help fix in place to produce long-lasting lift without the use of additional styling products.

What about the natural/organic angle? Aren't products without SLS "more natural" and therefore by the the law of faulty common sense, somehow better for you? For that point of view you might want to look at They go as far as to say that their shampoos are chemical free. I have no idea how that is even remotely possible given the fact that everything that exists is composed of chemicals. They state that "almost all shampoos contain harsh toxic chemicals that can damage your hair and weaken your health." As far as the argument that "natural = safe" goes, it is a faulty argument. Raw cinnamon oil is natural but I certainly wouldn't want to put any in my hair for fear it would get in my eyes and blind me.

So, what is the bottom line here? Do you really need to go SLS free or not? If your current shampoo is causing irritation, you may want to consider using a product without SLS. If the irritation is severe, you might want to consult your doctor about it. You might just want to go SLS-free to try a shampoo with a different and possibly more efficient surfactant. The point is that is it all your choice. Just don't let scare mongers make you feel like you have to go along with the latest fad in order to maintain your health.


The Ingredient Sodium Lauryl Sulfate Poses a Significant Risk To Shampoo Users,

Sodium Laureth Sulfate/Sulphate, Melbourne Dermatology

Cinnamon Oil is Dangerous, Gainsville Sun, 1985.

The Inconvenient Truth About SLS Free Shampoo, Top Article Source

Product Information,

SLS Free Shampoo, Squidoo

by Guy McCardle

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