Are sulfates in shampoo dangerous?

Sulfates are a class of chemicals that manufacturers use as cleansing or foaming agents. Many household products, such as foaming cleansers, toothpaste, and shampoos, contain sulfates.

Sulfates provide the foamy texture that occurs when a person mixes a product, such as a shampoo, with water.

Some people have concerns about the inclusion of sulfates in their cleansing products and shampoos. When people use them correctly in normal quantities, sulfates are generally safe.

However, some people may be more sensitive to specific products, and there are times when a person should avoid sulfates.

Keep reading to find out more about sulfates, why products contain them, and who should avoid them.
What are sulfates?

Sulfates are types of chemicals called surfactants that play an important role in the effectiveness of shampoos. Surfactants lower the surface tension of the liquid they are in, which makes the liquid easier to mix with water and work up into a good foam.
Why are sulfates in shampoos?
A shampoo may contain surfactants to make the liquid easier to mix with water.

The foaming action means that a person can spread the shampoo over a greater area of their head. It may also help any active ingredients in the shampoo work deeper into the hair to remove dirt and excess oil. Of course, this may also mean that the person uses less shampoo.

The most common sulfates found in store-bought shampoos include sodium lauryl sulfate, sodium laureth sulfate, and ammonium laureth sulfate. Other products may contain slight variations of these compounds, as well. These are not true sulfates, but they carry out the same role.
Are sulfates dangerous?

There may be some downsides to including sulfates in shampoo.

One downside is that sulfates may be too effective at cleaning. Sulfates help a shampoo to strip oil and dirt away from the hair. However, the hair needs to retain a bit of its natural moisture and oils to stay healthy.

Sulfates may strip away too much moisture, leaving the hair dry and unhealthy. They may also make the scalp dry and prone to irritation.

Aside from the possible drying effects, there is little risk to a person’s health from using sulfates correctly.

A review in Environmental Health Insights looked at the possible toxicity of sodium lauryl sulfate. The researchers noted that much of the negative public view of sulfates might be due to how people have interpreted the scientific reviews.

One of the most common myths surrounding sulfates is that they cause cancer. However, there is no scientific evidence to support this claim or that sulfates cause any harm to health.

Sodium lauryl sulfate might carry some minor risks, such as eye irritation, skin irritation, and general toxicity if a person drinks the product. However, most people should experience little or no side effects when using sulfates.
Who should avoid sulfates?

For the most part, the effects of sulfates are mild, and many people benefit from the effectiveness of shampoos that contain them. People with especially greasy hair or dandruff may notice that shampoos containing sulfates are the only products that clean their hair effectively.

However, some people should avoid sulfates and choose sulfate-free options. These people include:

People with sensitive skin or skin conditions

A person with a sensitive scalp or sensitive hair may experience strong drying effects from sulfates. Those with a skin condition such as eczema or psoriasis who use shampoo containing sulfates may also experience itching, redness, and cracking in their scalp after use. These people could consider using sulfate-free shampoos.

People with dry, frizzy hair

People with naturally dry, curly, or frizzy hair may want to avoid sulfates. Sulfates could increase the dryness and frizziness of hair due to increased friction caused by the stripping of the natural oils and moisture.

People with dyed and chemically altered hair

People who color their hair or regularly straighten or curl it may want to avoid sulfates as these processes can damage the hair. Finding ways to prevent any additional stress or dryness in the hair can help keep it healthy.

Shampoo containing sulfates may also strip the color from dyed hair more quickly.
Medical News Today Newsletter
Stay in the know. Get our free daily newsletter

Expect in-depth, science-backed toplines of our best stories every day. Tap in and keep your curiosity satisfied.