Toxic Shampoo and Personal Care Ingredients to Avoid

Reform Beauty Blog - Shampoo Ingredients You Want To Avoid

There are many brands in the beauty industry claiming to be "safe" or "non-toxic". But with so little regulations anything can be inside the bottle. Here are a few of the top ingredients to avoid.  


Sodium Lauryl Sulfate (SLS) is a surfactant, emulsifier, and a harsh detergent added to literally thousands of cleaners and cosmetic products and toiletries (shampoos, hair dyes, makeup, toothpaste, mouthwash, hand soaps, and laundry detergents).

SLS is made from petroleum or derived from coconuts, but during the manufacturing process, it undergoes “ethoxylation,” which results in an unwanted byproduct—1,4 dioxane. This byproduct contamination is suspected to be carcinogenic. Although there are no definitive studies proving a causative relationship, there is enough data to suggest caution.

The same concern applies to sodium laureth sulfate (SLES). Not only does SLES contain 1,4 dioxane, but it also contains ethylene oxide, which is what the “E” stands for in SLES, and this, too, is an impurity that is considered a potential carcinogenic agent.

The key here is that there are thousands of hair and skin care products that contain these byproducts, but it is the continued gradual use and its ability to gain access to our bodies that causes the potential hazard.

In this case, not only do SLS and SLES contain the bad byproducts, but also their molecular size is small enough to get into our skin and scalp, giving the bad byproducts entry into our bodies.

Conversely there are other cleansers that contain a small amount of these bad byproducts, but their molecular size is much larger, and so they do not get into our bodies. Therefore, these pose much less concern and health risk. Regardless, both SLS and SLES are harsh detergents and are irritants because they gain access to our skin and scalp.



The safety of SLS and SLES has been debated for a while now as thousands of small testing studies have been done, all with varying testing standards and therefore results. There still is no definitive clear-cut answer proving that the use of these chemicals in cosmetic products does cause disease. However, there is enough evidence to at least classify these as mild irritants and harsh detergents that have a molecular size small enough to get into our skin and scalp. There are thousands of ingredients to be aware of, way too many to list them all here. But below, for your viewing pleasure, is a list of some of the most common, top offenders to be aware of.


Ammonium lauryl sulfate, sodium laureth sulfate

Look for a shampoo that does not contain these ingredients, as they are harsh detergents.


Sodium Lauryl Sulfate

Sodium Lauryl Sulfate (SLS), another harsh detergent, is the agent in many shampoos that causes that foaming lather we often see in hair commercials.

What you don’t know is that exposing your hair to this chemical actually destroys it in the long run, stripping it of essential oils it needs to stay healthy, breaking down protein and halting healthy hair growth. Products containing SLS have a cleaning power that is overwhelming, stripping the hair.


Sodium Chloride

Better known as table salt, sodium chloride is used as a thickener in shampoos and conditioners containing sodium lauryl sulfate. Sodium chloride may also cause dry and itchy scalp in addition to hair loss. Also, this should be avoided in people who have keratin treatments, as it undoes the benefit faster.


Polyethelyne Glycol

Also called PEG/Polyethelyne or Polyoxyethelyne, this ingredient is included in shampoos as a thickening agent. It strips hair and skin of their natural moisture.


Diethanolamine (DEA) and Triethanolamine (TEA)

Products containing DEA or TEA can cause scalp irritation and bad allergic reactions, and they also destroy all the good stuff in your hair (such as keratin), making your hair dry, brittle, and lifeless.



Used to prolong shelf life of an average hair-care product, parabens like methylparaben and propylparaben are chemicals that are known for their toxic nature. Parabens not only irritate the skin—which can make your scalp unhealthy—they can also affect your hormonal balance, which can result in hair loss.



Excessive exposure to formaldehyde, which is found in some shampoos, may cause some hair loss.



Almost all hair-care products contain some form of alcohol, which can dry your hair out if it is in high concentrations. Stay clear of shampoos with alcohol listed as one of the first four ingredients, as this means that there is more [than usual] in the product.


Synthetic Fragrance or Parfum

This usually represents a complex mixture of dozens of chemicals. Some 3,000 chemicals are used in just one fragrance. Many fragrances are irritants and can cause the scalp to become irritated. In efforts of creating brand consistency, Reform limits the use of fragrance to a fraction of a percent.


Synthetic Colors

Artificial colors are used widely in hair-care products for aesthetic purposes. These ingredients frequently appear as FD&C or D&C followed by a color and a number. Color pigments may cause skin sensitivity along with scalp irritation.


Propylene Glycol

Also known as the antifreeze you put in your car, propylene glycol is a common ingredient in shampoos and other personal care products to keep the product from freezing during shipping and storage. It can irritate skin, causing allergic reactions, and it alters skin structure.


Lanolin, Petroleum, and Mineral Oil

These ingredients are widely used in greases and pomades formulated for ethnic hair and offer no real moisturizing benefits. These ingredients actually weigh the hair down and prevent the natural oils produced by the scalp from being absorbed by the hair shaft.



Dimethicone is a synthetic polymer and a form of silicone with two methyl groups attached (hence the name Di-methicone). It is usually used as a surface sealant in skin and hair products to coat surfaces in order to seal in moisture and act as a smoothing, texturizing additive.

Though silicone is a mineral - its safety has been called into question, as there are reports of people who react to this silicone derivative, which can cause irritation to the skin and scalp, resulting in chapped skin, rashes, burning, and itching.

The positive effects of silicone are plenty, starting with the fact that silicone provides slip and shine, can help smooth and straighten hair, and gives hair a luxurious, conditioned feel. 

Many trichologists and cosmetic formulators are on the fence with the safety data for this ingredient. 


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