Shampoo Ingredients That Can Cause Hair Loss
Risks, Causes, and Tips for Regrowth
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Medically reviewed by Casey Gallagher, MD
Shampoo is necessary to cleanse the hair and remove dirt, dust, pollen, and other pollutants that accumulate throughout the day. However, not all shampoos are great for your hair. In fact, the ingredients in some shampoos can cause hair loss. Among the ingredients that some people have found harmful are:
Sulfates
Dimethicone
This article looks at ingredients in shampoo, causes of hair loss, tips for hair growth, and when to see a healthcare provider.
Shampoo Ingredients That May Cause Hair Loss
It is estimated that shampoo contains anywhere from 10 to 30 ingredients, such as cleansing agents (surfactants), conditioning agents, special care ingredients, and additives. Some of these components have been linked to hair loss. However, clinical research is scarce.
Sulfates
Sulfates are chemicals with strong cleansing agents. The theory behind hair loss and sulfates is that ingredients like sodium lauryl sulfate damage and irritate hair follicles. Damage to the hair follicle may result in breakage, which can resemble or appear as hair loss.
Formaldehyde
At low levels, formaldehyde is considered safe. It is used in cosmetic products to kill bacteria and prolong shelf life. However, high levels of formaldehyde are classified as a group 1 human carcinogen by the International Agency for Cancer Research. Cosmetics also contain several formaldehyde donors, which are chemical compounds that slowly release formaldehyde.
Shampooing your hair daily should not directly expose you to high levels of formaldehyde. But formaldehyde from hair products can be released into the air, which at certain levels may irritate your eyes, nose, and lungs and cause skin sensitivity or allergic dermatitis. This type of exposure is more likely to occur in people who work at hair salons or those using hair straightening or smoothing solutions.
Several class-action lawsuits have been started against brands that use DMDM hydantoin, a known formaldehyde donor, even though the products were listed as formaldehyde-free. Claims suggest that these products cause scalp irritation and hair loss. While no clinical studies suggest this specific ingredient causes hair loss, it can cause scalp irritation. And an unhealthy scalp is associated with hair loss.
Keratin
Keratin is the major component of hair, so it makes sense that it is often used in treatments. These treatments are aimed at reducing fizziness and making hair shiny and strong.
There are problems with this wonder beauty product, though. First, keratin treatments often include formaldehyde, which are known to harm hair and health.
Second, the extreme heat used with keratin treatments can make hair brittle, which causes it to break and fallout.
Dimethicone
Dimethicone is a type of silicon product used in hair products. Silicon acts to protect your hair, but it can build up over time. In theory, this buildup could clog the pores in your scalp and prevent moisture and nutrients from getting to your hair, leading to hair loss. There's no research to back up this scenario, however. The best approach might be to use dimethicone, and all silicon products, with caution and discontinue their use if you notice signs of buildup or hair loss.
Do Ingredients Affect All Hair Types?
If you are sensitive to an ingredient that causes scalp irritation or hair loss, you probably will lose hair regardless of your hair type. Ask your dermatologist about the best product for you.
Related: 25 Reasons Your Hair Might Be Falling Out
FDA Stance and Recommendations
If you start using a product and experience hair loss, the FDA recommends you stop using the product immediately, report it, and contact your healthcare provider.
Deciphering Shampoo Label Ingredients
To keep your hair healthy, it's a good idea to read labels. Although the listed ingredients' meanings can be confusing, look for harsh chemicals like sulfates, as well as the following ingredients:
Formaldehyde
Formalin
Methylene glycol
DMDM hydantoin
Even if the product says "formaldehyde-free" or "sulfate-free," it's always good to read the ingredients list.
Ruling Out Other Causes
External factors, such as the weather (too much sun and wind), behavioral factors (smoking), and dietary factors (insufficient amounts of essential fatty acids and vitamins), can cause damage to existing hair and impair growth.
A person's age, race, and whether they have inflammatory conditions can also factor into hair loss. Use of high heat (hair drying, curling, straightening), waving or relaxing of the hair, and wet brushing can also damage the hair.
Some people may be genetically predisposed to hair loss. This appears to be more common in people with autoimmune diseases such as:
Atopic dermatitis
Alopecia areata, another type of autoimmune disease, occurs when the immune system attacks the hair follicles, leading to patches of hair loss on the scalp and other parts of the body.
Medication side effects, menopause, and stress can also cause certain types of hair loss.
Shampoo and Care for Hair Growth
A good hair care routine depends on the type of hair you have and the results you are looking for. People who have oily hair may have to shampoo daily, but those with dry hair can wash their hair less frequently. Consult with your healthcare provider or dermatologist for the best types of shampoo to buy. To maintain healthy hair, dermatologists recommend the following:
Shampoo daily with a mild shampoo, which is less irritating to the shaft.
Apply shampoo to soaked hair with fingertips and rub gently.
Avoid frequent perming.
Avoid frequent application of permanent dyes.
Avoid frequent bleaching.
Comb hair root to tip when dry.
Use wide-toothed combs and brushes with rounded tips.
Avoid frequent use of hair dryers.
Nutrition and Hair Loss
Adequate nutrition is important for health and hair regrowth. Certain nutrients are essential, such as iron, zinc, biotin, niacin, fatty acids, selenium, vitamin D, and amino acids. Deficiencies in these nutrients can lead to hair loss.
Most of the time, eating a diet rich in whole foods will satisfy your nutrient needs. The whole foods include:
Fruits
Vegetables
Protein (meat, legumes, poultry, fish)
Healthy fats (nuts, seeds, oils, avocado)
Whole grains (oats, quinoa, whole grain cereals)
Dairy products
If you cannot get enough nutrients through diet, you may benefit from testing for nutrient deficiencies and starting a supplementation regimen guided by a registered dietitian.
When to Contact a Healthcare Provider
Every day we shed hair—normally between 50 and 100 hairs fall out daily, but these will grow back as part of your hair's regular lifecycle. Certain medical or lifestyle factors can cause you to shed more hairs than normal. These include:
Losing 20 pounds or more
Giving birth
Experiencing stress
Being operated on
Stopping birth control pills
Recovering from an illness
Again, the hair you lose during excess shedding will be replaced by new hair. As you recover from your condition or adapt to the new status, the shedding will return to normal. If it doesn't, you should contact your healthcare provider to see if there is an underlying condition that is causing hair loss.
Unlike shedding, with hair loss your hair will not automatically regrow. The lost hairs will not be replaced by new ones. If you notice more than a normal amount of hair being shed for a long period of time or notice bald patches or a thinning scalp, you should see a dermatologist, who will be able to tell whether you have hair loss or excessive hair shedding.
Summary
While certain hair treatments are associated with hair loss, external conditions, stress, illness, immune health, and nutrition also affect hair health. Consider these factors when trying to determine what might be causing hair loss.
Reports to the FDA suggest that certain ingredients in hair products may cause hair loss. It is unclear whether these ingredients are definitely dangerous. However, formaldehyde and sulfates may be harsh on the hair and cause damage.
If you recently started using a hair care product and have noticed hair loss or scalp problems, you should see a healthcare provider. You can also report to the FDA that a product may be causing hair loss. Use the FDA’s MedWatch Online Voluntary Reporting Form or call 1-800-332-1088
