What's in Your Shampoo? Check for These Ingredients Before You Lather Up

But knowledge is power, so learning which shampoo and conditioner ingredients are best avoided — and why — means you can limit your exposure to chemicals that could have a negative impact on you, your hair, or the environment.

What ingredients are generally best avoided?

Skin care experts generally recommend avoiding certain shampoo and conditioner ingredients, no matter your hair type or styling preferences.

If you see any of the following on the label, you may want to keep shopping.


Sulfates, most commonly sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES), work as cleansing agents. They offer a deep clean and the sudsy lather many people expect from a shampoo.

Still, these harsh cleansers can strip your hair of its natural oils, which can lead to dryness. They also have a few other drawbacks:

  • skin irritation
  • dryness
  • inflammation
  • increased skin sensitivity
  • worsened symptoms of skin conditions like rosacea, eczema, and contact dermatitis

Sulfates don’t just affect your hair and skin. When you wash them down the drain, they flow into sewage systems and eventually to local rivers or the ocean, where they can wreak havoc on fragile ecosystems.


You’ll find this chemical compound in a number of household products — not to mention building materials, furniture, and paints.

In shampoos, it serves as a preservative, but it’s probably best to put any shampoos containing formaldehyde back on the shelf — it’s a known human carcinogen.

It can also lead to contact allergies or dermatitis and worsen skin conditions like allergic dermatitis and eczema.


These chemical preservatives have been used in beauty products for years to extend shelf life.

They do have antibacterial and antifungal properties, true. But they’re also rapidly absorbed through the skin and into bodily tissues, where they may:

  • affect breast cell tissue growth and possibly increase breast cancer risk
  • affect estrogen in the body, with potential consequences for menstruation and pregnancy
  • trigger allergic contact dermatitis
  • lead to skin issues like irritation, redness, flaking, and hives

Parabens can also cause ecological harm. Even low levels of butylparaben can kill coral.


This antiseptic agent is common in cosmetic products because of its antibacterial properties.

Still, it can cause eye and skin irritation, including:

  • redness and swelling
  • dryness
  • sensitivity to light
  • scaling

It’s also harmful if swallowed. It can cause nausea, vomiting, diarrhea, and abdominal cramps.


These man-made chemical compounds add flexibility to many plastics.

In shampoo, phthalates serve as a binding agent. They’re easily absorbed into the human body.

Experts have linked them to:

  • changes in hormone levels and function
  • low sperm count and infertility
  • Increased risk of pregnancy loss and gestational diabetes

They may also harm the:

  • kidneys
  • thyroid
  • liver
  • immune system

Phthalates are also environmental pollutants. They can affect reproduction in animals, just as they do in humans.


You’ll find this antibacterial chemical in plenty of products, including toothpaste and mouthwash.

In 2016, the Food and Drug Administration (FDA) banned its use in antibacterial soaps, but it’s still used in other personal care products, like shampoo.

Triclosan helps reduce bacterial contamination — but it’s easily absorbed into the skin and tissue, where exposure can affect reproductive health. It also makes its way into the sewage system, where it can harm any number of plant and animal species.

What about ingredients to avoid during pregnancy?

Clinical trials on pregnant women pose an ethical dilemma, of course. So there’s little evidence-based data linking common shampoo ingredients to any fetal harm.

Still, most healthcare experts would likely recommend erring on the side of caution, and it certainly wouldn’t hurt to avoid the ingredients above during pregnancy.

Phthalates, in particular, can:

  • increase the risk of miscarriage and gestational diabetes
  • impact gestational age and birth weight
  • affect the development of male genitals

One way to reduce exposure to phthalates? Avoid products that list “fragrance” or “parfum” as ingredients. Instead, look for products labeled “fragrance-free” or “phthalate-free.”

If you have questions about the safety of a particular product or ingredient during pregnancy, your doctor can offer more personalized guidance and insight.

What ingredients should you avoid if you have curly hair?

Curly or wavy hair is naturally drier than other types, so ingredients like sulfates and alcohols can be particularly damaging.

You may also want to avoid nonsoluble silicones. These products coat the hair shaft, smoothing the cuticle to reduce frizz and make your hair softer. Over time, though, the product builds up, leading to limp, lifeless locks. The same is true of mineral oil, waxes, and parabens.

Instead, look for natural oils and butters, including shea butter, jojoba, coconut, sunflower, and argan oils. These offer deep hydration for smoother, glossier curls.

Lightweight seed oils can also help detangle and moisturize curly locks. A few to try:

  • grapeseed oil
  • blackseed oil
  • Abyssinian seed oil

If you have dry or brittle hair?

Dry or brittle hair generally needs mild cleansing ingredients and extra conditioning.

Aim to avoid sulfates and alcohols. Instead, look for shampoos with oils, including avocado, macadamia, coconut, and olive, which can help nourish and hydrate limp, brittle locks.

Glycerin can also provide a moisture boos for dry hair.

What if you have rosacea or acne?

Another important consideration as you eyeball the ingredients on your shampoo and conditioner bottles? Their potential impact on your skin. If you have sensitive skin or deal with conditions like rosacea or acne, some ingredients can exacerbate symptoms.

To avoid irritating rosacea-prone skin, dermatologists recommend avoiding exfoliants like glycolic acid, alcohol, menthol, and witch hazel, in addition to sulfates.

Hair care products containing oil can also lead to acne cosmetica, or whiteheads along the hairline, the top part of the forehead, and along the back of the neck. Switching to an oil-free shampoo or noncomedogenic shampoo may help you avoid this type of breakout.

Shampoo ingredients to look for

Now that you know more about shampoo ingredients to avoid, you might wonder what ingredients you should seek out instead.

A few to look for:

  • Sodium lauroyl sacrcosinate is derived from sarcosine, an amino acid. This thorough but gentle cleanser has none of the risks of sulfates.
  • Sodium cocoyl glycinate, another amino-acid derived cleanser, is considered safe and nonirritating.
  • Disodium, a sulfate-free cleansing agent known for its degreasing benefits, is gentle on the skin, scalp, and hair.

Natural shampoos formulated with essential oils, botanicals, fruit extracts, and seed oils offer more options. These shampoos tend to cleanse more gently, boosting hydration without irritating your scalp or stripping your hair of natural oils.

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