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Can Shampoos Cause Hair Loss?

Medically reviewed by
Dr Mir Malkani — Updated on December 29, 2025

If you’re worried about your hair falling out, you may find yourself hunting for a potential cause. This could lead you to blame one of the products you use on your hair frequently – your shampoo.

All it takes is a quick search online to be bombarded with information about damaging chemicals and ingredients in shampoos that cause hair loss but this isn’t always true.

Keep on reading to find out more about whether your shampoo and hair washing could really be the cause of your sudden hair loss.

Table of Contents

Why does hair fall out?
Can shampoo cause hair loss?
Can shampoos help improve hair loss?
How can I stop my hair from falling out?
When should I consider a hair transplant?

Why does hair fall out?

To understand why your hair may be falling out, you first need to understand the hair growth cycle that your hair goes through. This cycle consists of four different stages:

Anagen, where your hair is actively growing
Catagen, where your hair stops growing
Telogen, where your hair is in a ‘resting’ state
Exogen, in which your hair sheds from the follicle to make way for regrowth

This is a cycle that everyone’s hair goes through, even those who have long, luscious locks. In fact, it’s absolutely normal to lose between 50 and 100 hairs every day without any cause for concern [1].

Excessive hair fall that goes beyond the normal rate can be brought on by a range of triggers, including ageing, changing hormones, or even stress, which often has nothing to do with the hair products you use. So can shampoo cause hair loss, too?

Can shampoo cause hair loss?

Shampoo and hair washing in general is rarely a direct cause of hair loss. The American Academy of Dermatology (AAD) doesn’t list any shampoos or ingredients that are commonly found in shampoos as causes of hair loss [2].

However, research suggests that certain ingredients can impair your hair. This includes antimicrobial agents, surfactants, and preservatives [3]. Here are some of the most common shampoo ingredients that can directly or indirectly lead to hair loss.

Sodium dodecyl sulphate (sodium lauryl sulfate)

Sodium dodecyl sulphate, also known as sodium lauryl sulfate, creates a lathering effect in many shampoos. This makes shampoo easy to apply and effectively cleanses your tresses.

Some research shows that sodium dodecyl sulphate can cause your hair to lose protein [4]. Hair mainly consists of a type of protein called keratin. Loss of protein damages the keratin, leading to split ends and difficulty brushing your hair, which is why keratin for hair treatments are sometimes used. Breakage and inadvertently pulling out hair strands that aren’t in the telogen or exogen phases may lead to hair loss.

The more damaged your hair already is, the worse protein loss can be. So if your hair is already looking a little worse for wear, avoid shampoos that contain sodium dodecyl sulphate. Consider switching to a shampoo that contains sodium laureth sulphate instead — this is a common moisturising shampoo ingredient which is less irritating than sodium dodecyl sulphate [5].

DMDM hydantoin and formaldehyde

DMDM hydantoin, a common shampoo ingredient, has been in the news recently thanks to claims it causes hair loss. While it won’t directly cause your hair to fall out, there is some evidence it could lead to conditions that may impact your hair.

DMDM hydantoin is a preservative and antimicrobial agent which releases small amounts of formaldehyde into the product. These small quantities aren’t considered harmful to most people, although approximately 8-9% of people who come into contact with it may experience an allergic reaction [6-7].

This reaction often leads to contact dermatitis, a type of skin irritation [8]. While this won’t always cause hair loss, contact dermatitis of the scalp has been linked with telogen effluvium [9-10].

Selenium sulphide

This ingredient reduces itching associated with skin irritation, minimising the risk of hair loss related to dandruff and seborrheic dermatitis [11]. However, another study suggests shampoos containing selenium sulphide can actually cause diffuse hair loss (hair thinning) across the scalp [12].

Selenium sulphide has also been linked with scalp discolouration. Needless to say, while this is unlikely to cause hair shedding, it’s an unsightly side effect you probably want to avoid [13].

As a result, it’s a good idea to avoid shampoos containing selenium sulphide unless you have severe dandruff or severe scalp irritation. You should also avoid taking selenium supplements for your hair unless prescribed by a doctor or trichologist.

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Can shampoos help improve hair loss?

Some shampoo ingredients are proven to actively reduce hair loss, including:

Zinc pyrithione — this has been shown to keep your scalp healthy, reduce dandruff, and prevent premature hair loss. It’s found in mainstream shampoos like Head & Shoulders [14]
Caffeine — topical caffeine solutions have been shown to be effective at reducing hair loss if left on the scalp for an extended period [15]. Learn more about caffeine for hair loss.
Ketoconazole — specialist shampoos containing ketoconazole can improve hair density [16]. However, alopecia is listed as a known side effect of Nizoral, which contains ketoconazole. Learn more about Nizoral shampoo and hair loss.
Salicylic acid — another popular anti-dandruff ingredient, shampoos containing salicylic acid have been linked with successful treatment of alopecia areata [17].

Not all shampoos contain all these helpful ingredients. So if you need to treat a scalp condition or promote healthy hair growth, check the shampoo ingredients list first.

Some shampoos are specially formulated for certain hair loss types, such as these shampoos for menopausal hair.

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How can I stop my hair from falling out?

If you’ve noticed lots of hair falling out in the shower when you wash it, it may seem like your shampoo is the problem. However, in the majority of cases, there’s probably something else that is responsible for causing excessive hair loss.

Your GP or a trichologist can help you identify the cause of your hair loss. Once you know what the cause is, you’ll find it much easier to stop further hair loss and improve your overall hair health.

For some people, the solution may be as simple as making small lifestyle changes, such as minimising the use of heat-styling products, switching to a caffeine shampoo or another hair growth shampoo, and/or using stress-relief techniques to regain hair loss after stress.

For others, especially those who are experiencing more advanced hair loss, you may need to look into over-the-counter hair loss treatments. Some of the most popular include Finasteride, Dutasteride and Minoxidil.

When should I consider a hair transplant?

However, if you’ve tried all the above and still find that your hair is falling out, you may be interested in getting a hair transplant. A recent study found the average cost of a hair transplant in the UK to be £4,820.

A hair transplant involves taking healthy hair follicles and reimplanting them to areas of the scalp where you’re experiencing balding. It’s a quick, long-lasting procedure that can make a real difference to people with male pattern baldness or female pattern hair loss. Learn more about how hair transplants work.

At Wimpole Hair Clinic, we’ve helped thousands of men and women deal with hair loss. If you’d like to learn more about hair transplants and how they could work for you, book a free consultation with our team.