Bumble and bumble. Hairdresser's Invisible Oil Hydrating Shampoo Versus MoroccanOil Smoothing Shampoo

Glycerin is already naturally found in your skin. It helps moisturize and protect your skin.

A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.

Linalool is a fragrance and helps add scent to products. It's derived from common plants such as cinnamon, mint, citrus, and lavender.

Like Limonene, this ingredient oxidizes when exposed to air. Oxidized linalool can cause allergies and skin sensitivity.

Parfum is a catch-all term for an ingredient or more that is used to give a scent to products.

Also called "fragrance", this ingredient can be a blend of hundreds of chemicals or plant oils. This means every product with "fragrance" or "parfum" in the ingredients list is a different mixture.

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Polyquaternium-7 is a light to clear colored liquid. It is commonly found in haircare products for its film-forming and anti-static properties.

According to a manufacturer, it is a non-paraben and specially developed for negatively charged surfactant systems. This makes it a great hairstyle holder and helps to improve wet hair detangling without adding buildup.

Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Sodium Lauroyl Sarcosinate is a cleansing agent and emulsifier. It is a surfactant derived from sarcosine, and a common source is coconut oil.
As a surfactant, Sodium Lauroyl Sarcosinate helps lift dirts, oil, and other molecules to be washed away. In leave-on products, this ingredient is used as an emulsifier. Emulsifier help prevent ingredients such as oils and waters from separating.

Sodium Lauroyl Sarcosinate is also commonly found as a foaming agent in shampoo, toothpaste, and shaving foam. It is amphiphilic, meaning it loves both water and fats.

Sodium Lauryl Sulfoacetate is an organic salt with a naturally sweet odor. It is an alternative to traditional sulfates and is commonly found in "sulfate-free" products.

In cosmetics, this ingredient is used to increase the volume of foam, emulsify ingredients, and as a cleansing agent.

Tetrasodium EDTA is the salt formed from neutralizing ethylenediamine tetraacetic acid with sodium hydroxide. It is a chelating agent and used to prevent metal ions from binding to other ingredients. This helps keep the product and ingredients stable.

Tetrasodium EDTA comes as a white solid and is soluble in water.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.