Joico Hydra Splash Hydrating Shampoo Versus Paul Mitchell Sheer Hydration Conditioner

This ingredient is derived from guar gum.

It is a conditioning ingredient, meaning it helps soften skin and hair.

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.

MCI is a preservative and known skin-irritant. It has anti-bacteria anti-fungal properties.

Studies spanning several decades have shown this ingredient to cause skin irritation and allergies.

MI is a preservative and known skin irritant. In the past, MI was used for its ability to prevent bacteria, yeast, and fungi growth in low doses.

Nowadays, you'll most likely see MI combined with Methylchloroisothiazolinone (MCI). Trade names for this combination include Kathon CG or Euxyl K 100.

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.

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.