What's the Deal with Sulfates, Anyway?

There has been a tremendous move towards healthy living in recent years. Personal care products touting themselves as “natural” are all the rage, but “natural” doesn’t necessarily mean “better.”

The abundance of inaccurate information that’s easily accessible to consumers on the internet has created unfounded fear of particular ingredients, and the claims that they are harmful are not proven or backed by science. The word “chemical” has a negative connotation, but let me remind you that chemicals like antibiotics save lives, and a natural substance like poison ivy is one of the most common culprits of allergic contact dermatitis.

We see the “sulfate-free” label everywhere on personal and beauty products, particularly those for the hair. What do they do and are they truly bad for our health? As a dermatologist, I want to properly educate the general public with evidence-based information that’s accurate, so let’s debunk some myths.

‌‌‌‌What Are Sulfates?

Sulfates are a type of chemical called surfactants. They are put into shampoos and cleansers to reduce surface tension between water, dirt, and oil, therefore allowing products to lather and foam more readily. This is desirable, as it allows shampoo to spread easier throughout the head.

Sulfates also help active ingredients in products to penetrate better, making it more effective at removing dirt, oil, and chemicals that have been sitting on your hair. For those with oily or greasy hair, sulfate-containing shampoo may be desired as it can more effectively clean the scalp.

The most common forms of sulfates in personal beauty products, typically shampoos, are sodium lauryl sulfate and sodium laureth sulfate.

‌‌‌‌The Problem with Sulfates

Because they are very effective cleaners, sulfate-containing shampoos may strip too much of the natural oil, leaving our scalp and hair feeling dry and brittle. Sulfates could potentially cause irritation and even dermatitis in some users, but—and this is important—most people tolerate them just fine.

Sulfates do not pose a personal health risk if used as personal care products and not ingested. The concern of sulfates being a carcinogen has not been scientifically proven.

‌‌‌‌Should I Avoid Sulfates in My Hair Products?

It depends. If you fall into one of these categories, you may want to avoid sulfates:

• If you have sensitive skin, a personal history of eczema, or dry scalp, you may want to consider using sulfate-free shampoo. Sulfate-based products may act as a potential irritant or allergen. In people with conditions like atopic dermatitis, psoriasis, or severe seborrheic dermatitis where the scalp is inflamed, these products may further aggravate the scalp, leading to more pronounced itching, redness, oozing, and flaking.
• People with dry or fragile hair should also avoid sulfates. These shampoos can increase dryness, hair breakage, and frizziness by stripping the hair’s natural oil.
• Those with chemically-treated hair, whether by coloring or chemical processing, should avoid sulfates. The idea is the same as above. These individuals tend to have drier hair. Sulfates will add more stress to your already damaged hair. Additionally, sulfates can wash away hair color more quickly, which is not desired.
• The American Academy of Dermatology also recommends that anyone with rosacea avoid sulfate-based personal care products as they are known to trigger inflammation. Individuals with rosacea have sensitive skin that can burn and present as rosy cheeks with pimple-like breakouts on the nose, cheeks, and chin. Sulfates have been shown to trigger the symptoms and increase redness.

‌‌‌‌Do I Have a Sulfate Allergy?

Worried you may be reacting to your sulfate-containing shampoo? Here are some signs and symptoms you should look for:

• Redness, itching, or swollen skin: This is most commonly found around the eyelid, forehead, cheeks, neck, and particularly the back of the neck. This is often caused by shampoo contacting the skin during the process of rinsing. Our scalp is much more hardy than our skin, so ironically, it may not react even if you have a true allergy to sulfates.
• Worsening skin conditions: If you have a scalp condition such as eczema or psoriasis, and it gets worse after using sulfate-containing shampoo, then sulfates could be the culprit. The rash could develop right away or in a few days after repeated use.

If you suspect you are reacting to sulfates in your products, you should speak to a dermatologist to help you discover if it’s the sulfates or something else.

‌‌‌‌My Recommendations About Sulfates

In general, I recommend using sulfate-free shampoo mostly for the health of the hair and scalp, not because of any potential health risk. Medically, those with inflammatory conditions affecting the scalp would also benefit from sulfate-free shampoo to avoid further worsening of their preexisting scalp disease.

For those with very greasy scalp or a desire for a squeaky-clean feel, sulfate-containing shampoos do the best job at effectively removing dirt, oil, and debris. There is no better substitute chemically.

Many people with dry, fragile, or damaged hair wash their hair less frequently to avoid dryness. Although this is helpful for protecting the hair shaft, the buildup of oil, sebum, and debris from infrequent hair washing can lead to clogged hair follicles, scalp inflammation, worsening of dandruff, itching, and even hair loss. Therefore, for these people I recommend washing hair 2-3 times weekly, using a very gentle, sulfate-free shampoo formulated specifically for their hair type. When shampooing, only apply to the scalp, avoid the hair, and make sure to condition afterwards.

I also recommend using a deep conditioning treatment once weekly, especially for those with chemically-treated or dry, fragile hair.

‌‌‌‌My Favorite Sulfate-Free Hair Products

Two of my favorite brands for sulfate-free hair products are Living Proof and Moroccanoil. These lines have a selection of shampoos and conditioners for various hair needs. I frequently balayage my hair, so it’s pretty damaged. I often use products specifically for chemically-treated and dry hair. I’ve found these shampoos to be less drying and their conditioners to be more moisturizing for my hair. I only wash my hair twice a week—excessive hair washing can dry out the scalp and hair.

Pureology is another line that I recommend, especially for those who color their hair. Their line of shampoos is specially formulated to help preserve color and vibrancy throughout washes.

There are many brands with sulfate-free products on the market today. It’s important to note that while these products may not contain sulfates per se, they may have similarly-structured chemicals as a substitute. If you are concerned about the ingredients in your hair products and their effects on your hair and scalp, please see your dermatologist for help with diagnosis and recommendations.