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3 Ingredients to Avoid in Your Shampoo

Updated: Apr 7, 2021

Shampoo is something we use all the time (sometimes too often) and it is so important to know what you are putting on your hair. We may only use a little bit each time but over a lifetime that is a lot of product and possibly a lot of problematic ingredients going into your skin. Here I researched 3 ingredients that should be avoided and named a few brands that use them. Remember to always check ingredients when buying your products!

Enjoy this read and, as always, click the numbers in square brackets to check out all the references!

Sodium Lauryl Sulphate or SLS

SLS has a powdered salt or baking soda like appearance

What is it?

Sodium Lauryl Suphate or Sodium Laureth Sulphate (SLS) is a surfactant which means it reduces surface tension between liquids so that they can spread easily and create foam [i].

Why should you avoid it?

SLS is put in shampoos because when it reduces surface tension, it allows dirt and oils to be loosened and washed away, and makes that luscious lather that everyone loves. The problem is that it is also an irritant. SLS is used in medical research because it induces contact dermatitis on skin in animals and humans [ii,iii]. It is usually formulated to be non-irritating in shampoos, but can still cause dry skin and even more severe issues like eczema [iv]. I also found research indicating that increased exposure to water while in contact with SLS can increase the irritation of SLS to the skin [v]. Obviously this is an issue since you are exposed to water while washing your hair.

On a different note, SLS is produced partially from palm kernel oil [vi]. Palm oil production has caused huge amounts of deforestation and has severely negatively impacted many species, most notably orangutans[vii].

Silicones: A friend of mine made a good point that a lot of products she uses have silicones that build up on her hair and the most effective way to get them off is using SLS shampoos. If this is the case for you try using an SLS-free clarifying shampoo once every few weeks like Acure Organics Clarifying Shampoo or Green People Clarifying Vitamin Shampoo. I will do an article on silicones soon so stay posted!

Shampoos that use SLS

Many companies still use it including Bumble and Bumble, Pantene Pro-V, Garnier, Tresemme, Redken, Head and Shoulders, Schwarzkopf, L’Oreal, and plenty of others. Some of these companies offer “Sulphate Free” lines so these might be something to consider.


Methylparaben on the left and Isopropylparaben on the right

What are they?

Parabens are preservatives used in many cosmetic products to give them a very long shelf life[viii]. They have many names including methylparaben, ethylparaben, propylparaben, butylparaben, isobutylparaben, isopropylparaben, and benzylparaben.

Why should you avoid them?

Parabens are preservatives used in many cosmetic products to give them]. Palm oil production has caused huge amounts of deforestation and has severely negatively impacted many species, most notably orangutans [pro-paraben argument is that the amount of one type of paraben in your average shampoo bottle is very low and most studies indicate that a single exposure this low is far too small to have any effect on the body [xii]. The problem with this is that the majority of studies only account for a single exposure in one product and not for multiple parabens in many products used multiple times a day [xiii]. A disturbing study found that high paraben concentrations in young women were associated with shorter menstrual cycles and might negatively affect female fertility [xiv].

Shampoos that use parabens

Parabens are falling out of favour with many companies since consumers have caught wind of them but you can still find them in Kérastase shampoos, Aussie shampoos, John Frieda shampoos, and in many other cosmetic products.


What is it?

Formaldehyde is a chemical used in building materials and in the production of household materials [xv]. It is also a main ingredient used for embalming dead bodies! You won’t find formaldehyde directly on a label but you can find preservatives that slowly release formaldehyde over time. These include polyquaternium-7, polyquaternium-10, quaternium-15, diazolidinyl urea, DMDM hydantoin, bronopol, and imidazolidinyl urea [xvi].

Why should you avoid it?

First off, our cells produce some formaldehyde as a natural byproduct of the one-carbon cycle which makes things like DNA. We have two processes that remove/detoxify the formaldehyde but these processes cannot neutralize everything we are exposed to [xvii]. I focused on research about formaldehyde coming from outside the body in amounts too high for our cells to cope with.

Formaldehyde has been proven to be a carcinogen [xviii,xix] (causes cancer) and has been proven to permanently damage your DNA [xx,xxi,xxii]. These formaldehyde releasers do not release huge amounts but like parabens, small and consistent daily exposure can have negative effects over your lifetime.

Shampoos that use formaldehyde releasers

Many shampoos use some form of formaldehyde releasers including Bumble and Bumble, Marc Anthony, John Frieda, Moroccanoil, Living Proof, Herbal Essences, Pantene Pro-V, Tresemmé, and L’Oreal.

Shampoos that avoid all three ingredients

Natural Spa Factory-check it out here

The Organic Pharmacy-check it out here

Faith in Nature-check it out here

Rahua-check it out here

Final Thoughts

I encourage everyone to always read labels because it only takes a few moments and can make a difference to your health. Always check to see if brands have Sulphate Free and Paraben Free lines and if you love any of the brands that use these ingredients I recommend contacting them and asking that they remove them! Brands want to keep their customers happy, and the the only way they’ll know that you want a change is if you tell them.

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