15 Harmful Ingredients In Shampoos And Conditioners For Fine And Dry Hair

April 25, 2023
by Christine Devereaux

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How do you decide which products to use on your hair? If you had to rely solely on the ingredients list, would you know which products to use or avoid?

Most commercial shampoos and conditioners contain an abundance of chemicals, many of which we’ve never heard of. So, how can we trust they’re good for our hair health? 

Unfortunately, many of these chemicals can be toxic to our hair health, especially if you already have fine and dry hair.

In this post, we’ll be walking you through a selection of some of the most toxic ingredients in shampoos and conditioners that you should be avoiding. 


Woman looking at her hairbrush wondering what is bad in shampoo for fine and dry hair after lots of hair in brush

First up we have formaldehyde. Formaldehyde and formaldehyde preservatives are used in many shampoos, conditioners, and personal care products, and it’s something you may want to eliminate from your routine.

Formaldehyde is a common carcinogen, and it’s easily absorbed into your scalp and can escape from packaging and release into the air.

Not only does this chemical have links to asthma and cancer, but it can cause allergic reactions, hair loss, and dermatitis - especially if you already have dry hair. 


Next up, we have phthalates. Phthalates are one of the leading causes of eczema, which can damage your hair health and cause a dry, irritated scalp that will also dry out your hair.

Phthalates have also been linked to some pretty serious symptoms and conditions, such as worsened allergies, lower testosterone levels, behavioral changes, insulin resistance, early onset puberty, and more.

Phthalates are found in both shampoos and conditioners and can be damaging to all hair types. 


Triclosan is a chemical that’s usually found in shampoos, and as a proven endocrine disruptor, it can damage cellular reproduction which can lead to hair loss, hair damage, and delayed hair growth.

It can also cause inflammation and dryness on dry scalps.

This endocrine-disrupting chemical may also damage hormone function, and decrease specific thyroid hormones, although more evidence is needed to confirm this. 

Polyethylene Glycols (PEG)

Polyethylene Glycols (PEG) are used to improve the texture of shampoo.

Unfortunately, this synthetic ingredient can be harsh on your hair; although it’s supposed to mimic moisturizing qualities, it can actually dry out your hair and damage new growth.

This can be particularly harmful to people with fine hair, who may be more susceptible to hair loss and irritation.  


With long-term use of dimethicone, you may experience dry, damaged hair and frequent breakage.

Dimethicone is found in shampoos, conditioners, and other personal hair care products, and it’s a type of silicone that’s used to make your hair feel smoother.

Unfortunately, though, some people may be more susceptible to its negative effects. 


Unfortunately, parabens are one of the most common ingredients in shampoos and conditioners, but they can also be the most damaging.

Parabens are a group of chemicals used as preservatives that are associated with irritated scalps, dry hair, faded color, and occasionally hair loss. If you have a dry, irritated scalp, we’d recommend avoiding parabens. 


Woman with lots of dandruff in hair

Shampoos that contain alcohol are often harsh on your hair. The alcohol can act as a drying agent that damages your scalp and causes dryness and dandruff.

Isopropyl alcohol is one of the most common types of alcohol found in shampoos and conditioners, and although they’re supposed to improve your hair's condition, they may cause more harm than good. 

Retinyl Palmitate

Next up, we have retinyl palmitate. Retinyl palmitate is used in a variety of hair care products and personal care products, such as moisturizers and body washes.

Although it’s considered safe for use, retinyl palmitate may cause scaling and peeling of the scalp, and in people with existing conditions, it can even cause temporary hair loss. 


Sulfates are chemicals used as cleaning agents and detergents, and they’re often found in soaps, shampoos, and conditioners.

In shampoos, sulfates create a layer of froth that cleanses dirt, debris, and oil.

That may sound good, but sulfates have plenty of downsides. They’re damaging to the environment and aquatic life, and they can also cause allergic reactions, brittle hair, and a dry scalp. 

Behentrimonium Chloride  

This type of ammonium salt is used as a preservative, but in most hair care products, it acts as an anti-static ingredient that conditions hair.

In concentrations above 0.1%, it’s considered toxic, and although it can be beneficial to your hair, some users are more prone to irritation. Scalp and eye irritation are most common in users with dry scalps. 

Selenium Sulfide 

Next up, we have selenium sulfide. Selenium sulfide is often used in anti-dandruff shampoos, and is also said to relieve itching and irritation.

Unfortunately, selenium sulfide is also a known carcinogen and it’s linked to an increased risk of cancer.

For some dandruff sufferers, it can even exacerbate symptoms by drying out natural oils, irritating existing redness, and damaging hair texture, which is bad for fine hair and dry scalps.

If you have sensitive skin, use this ingredient with caution. 


Toluene is a type of toxic chemical used in different hair products and hair dyes.

This petrochemical solvent and paint thinner can be damaging to the environment and human health, and many people who use it report scalp irritation, breathing difficulties, and even nausea.

It can dry out the skin significantly which can aggravate existing conditions, such as dandruff, and it may even cause hair loss, which is bad news for people with fine hair. 

Synthetic Fragrances and Colors 

Synthetic fragrances and colors are made from a variety of toxic chemicals, and they’re probably causing your hair (and your health) more harm than good.

Fragrances are usually just labeled as ‘fragrance’, while colors will read FD&C or D&C with a number.

Not only are these linked to a number of harmful health effects, but they also cause persistent skin irritation that can damage the scalp and lead to long-term hair loss. 

Sodium Chloride 

Next up, we have sodium chloride. Although sodium chloride is not thought to be toxic, it can often dehydrate your hair and leave it feeling dry and brittle.

People with fine hair often report more hair loss, a drier texture, and a duller appearance.

Sodium chloride is usually used in shampoos and conditioners to give them a thicker consistency, but we’d advise steering clear of this ingredient. 

Cocamidopropyl Betaine 

Last up, we have cocamidopropyl betaine. This surfactant is added to shampoos and conditioners to help lift dirt and oil from the skin and the hair.

Although it’s considered safe and non-toxic, these kinds of detergents can wreak havoc on sensitive skin.

If you have a naturally dry scalp, dry skin, or fine hair, you may notice that this ingredient worsens your symptoms, even though it’s considered gentler than other surfactants.

It has also been linked to aggravated allergies, eczema, and rosacea. 

The Bottom Line 

Although we’d like to think our shampoos and conditioners protect our hair, many products contain harmful ingredients that can cause irreparable damage and irritation, and worsen existing conditions.

Before you choose your next product, scan the packaging for these 15 additives you should be avoiding. 

Related: The 6 Best Dandruff Shampoo For Men Options For Shiny Hair

About the Author
Christine Devereaux is a style and gear junkie. She loves the outdoors and picking out clothing and home goods for her husband, son and dog.
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