Research Team

Does Hard Water Cause Hair Loss?

You’ve been avoiding harsh hair products, eating the right types of food to keep your hair healthy, and have been doing your due diligence when it comes to scalp care.

And yet, you’re losing more hair strands than usual.

Hard water might be the culprit.

The relationship of hard water to hair loss has been a hot topic for years. It’s being debated on different discussion websites and has been featured on medical journals.

A couple of studies were even conducted to shed scientific light on the matter.

The results of the studies are conflicting because the mechanism in which this happens is far more complex­—and highly interesting—than we think.

You’ll see why in a minute.

Before we go into that, let’s first define what hard water is in order to better understand its relationship to hair loss.

What is Hard Water?

You probably blamed those ugly water stains on your sink or cookware to improper cleaning.

Those watermarks are not signs of sloppiness. They are actually scale deposits of hard water.

Hard water is one of the types of water that is classified based on its hardness or the amount of minerals found in it.

Hard water has a high concentration of minerals such as calcium, magnesium, and other dissolved compounds, like bicarbonates and sulfates.

Majority of the water in your home is groundwater; the rest is surface water. Groundwater is water that is found beneath the soil.

As groundwater travels to your home, it will pass through rocks and soil within your area, absorbing minerals as they go.

If the dominant minerals in your area are dolomite and limestone, the hardness level of your water supply will be high.

The main compound that causes hard water is CaCo3 or Calcium carbonate. This is why the hardness level of water is measured in CaCo3 mg/L.

There are four types of water according to its hardness value. The World Health Organization uses the EDTA (edetic acid) Method in determining the hardness of water (1).

You can find the different water hardness values from the table below:


(CaCO3 mg/L)

0 – 75 Soft Water
75 – 150 Moderately Hard Water
150 – 300 Hard Water
More than 300 Very Hard Water

Hard water is not unique to a specific region. In fact, there is hard water all over the world.

England, for example, has very hard water according to the Drinking Water Inspectorate’s (DWI) 2018 report (2).

In Australia, the city that has the highest concentration of CaCO3 mg/L in its water supply is Adelaide.

Other hard water regions include the Canadian Prairies and the U.S. Midwestern and Southwestern states.

Below is a map from the United States Geological Survey (USGS) that shows states with hard water (3).

For the most part, water is one of the safest things we can use on our hair, skin, and body. That’s true.

But to some extent, all types of water can be double-edged swords, meaning most parts of our bodies will benefit from it, but some will not.

In the case of hard water, our bones, teeth, and heart will be happy to receive it, but our hair and skin might not.

Even rain—considered to be the “purest” form of water—can be harmful. It picks up impurities as it travels through the atmosphere causing it to have a high acidity level once it hits the ground. Hence the term “acid rain.”

Now that we’ve covered most of the bases about hard water, let’s now take a look at hair cycle and hair loss.

Hair Cycle

Losing hair is part of the natural cycle of hair. We regularly lose hair in order to pave way for new hair growth.

It is when the cycle is prematurely disrupted or when there’s no new growth that will be a cause for concern.

There are two important parts of hair, namely:

  1. Follicles – the part of the hair that is hidden beneath the surface of the scalp and is known as the living part of the hair.
  2. Shaft – the dead part of the hair that protrudes from the scalp.

The follicle’s papilla has capillaries and blood vessels that supply oxygen and nutrients to the bulb. The cells of the bulb divide much faster than the rest of the cells in the body.

Chemotherapy patients lose hair because of this reason. Chemotherapy attacks fast-growing cells like the cells of the bulb.

Natural hair loss doesn’t all happen at once, but rather at different intervals. Below are the three phases of the scalp hair cycle (4):

  1. Anagen – a phase of the scalp hair cycle when hair is actively growing. This lasts for about two to seven years.
  2. Catagen – also known as the transitional phase. During this phase, the hair is nearing the end of its final growth. It is during this phase when club hair is formed. Club hair features a bulb that anchors the strand to the follicle until it’s pushed out by a new growth. Catagen phase lasts for three weeks to a month.
  3. Telogen – this is the phase when the hair stops growing and shedding occurs. Also known as the resting phase, telogen lasts for 100 days. A normal human being sheds about 100 telogen strands each day.

What is Alopecia?

Alopecia is the medical term for hair loss.

There are several reasons why alopecia happens. If you’re suffering from it, one of these might be the reason why:

  • Heredity – This is the most common cause of alopecia for both male and females (5).
  • Medical conditions – Examples of these are autoimmune thyroid diseases that can stall hair growth and trichotillomania (hair-pulling disorder).
  • Hormonal changes – Temporary or permanent hair loss happens during pregnancy, childbirth, and menopause.
  • Stress – Stress causes hair to fall out quickly and forces the hair follicles to temporarily remain in a resting phase.
  • Medications – Certain drugs have side effects that disrupt the hair cycle. The S. FDA reports show that people (especially women over 60 years of age) who take calcium carbonate orally on a regular basis suffer from hair loss (6). Calcium carbonate, as we have discussed earlier, is the main compound of hard water.
  • Radiation therapy – The sensitivity of hair follicles to radiation causes the shaft to prematurely fall out. Typically, the hair will grow back within 3 to 6 months.
  • Hairstyles and hair treatments – Continuous stress on the hair and exposure to harsh chemicals weakens both the shaft and the roots.
  • Environmental irritants – These irritant force the cycle to immediately move from the anagen phase to telogen phase without going through the catagen phase.

But just as there are many different causes of hair loss, so too are there many different types.

Types of Alopecia

To better understand hair loss in general, it helps if you understand the different types that can occur. These include:

  • Alopecia Totalis – complete loss of scalp hair.
  • Alopecia Universalis – complete loss of body hair.
  • Androgenetic Alopecia – a genetic condition more commonly known as male-pattern baldness or female-pattern baldness.
  • Alopecia Areata – hair falls out in small patches.
  • Diffuse Alopecia – there are no obvious bald spots, but a diffuse thinning can be seen all over the scalp. This is also known as alopecia areata incognita.
  • Postpartum Alopecia – a temporary condition that happens near the end of pregnancy and after the woman has given birth. Excessive shedding of hair lasts for about 6 to 9 months after childbirth.
  • Traction Alopecia – a type of hair loss caused by constant pulling of hair. The repeated tension causes hair shafts to break. This can be due to heavy use of hair styling tools (e.g. hair dryers and straightening irons), tight ponytails, hairstyles such as weaves and braids, and hair treatments that can irritate the shafts leading to hair loss.

Can Hard Water Cause the Hair to Fall Out?

This is not a typical yes-or-no question. It’s more of a yes-and-no question…plus some heavy explanation.

Hair loss is a complex disorder. Even with the advancement in technology these days, its exact pathogenesis still puzzles medical experts.

Much has been said about the detrimental effects of hard water on the skin, but when it comes to hair loss, the results are still unclear.

Hard water has been linked to the development of eczema (7). It is believed that hard water weakens the skin’s barrier.

This, in turn, increases the risk of a person to develop eczema as well as make the skin susceptible to irritants.

Little is known about the contribution of hard water to hair loss. Actually, there’s still not enough data on hair loss in general.

Take the case of Telogen effluvium (TE). It is considered by dermatologists to be the second most common cause of hair loss, and yet very little research is being done to better understand it.

Scientific Studies

In order to provide you with the best possible answer, we looked into these three prominent scientific studies that were performed on separate occasions by different researchers:

  1. Effects of hard water on hair
  1. Effect of topical application of hard water in weakening of hair in men
  1. Evaluation and comparison of changes in baseline strength of hairs after they have been treated with deionized water and hard water and its role in hair breakage

In all the studies, the researchers aimed to find out the tensile strengths of hair shafts that were treated with hard water.

Tensile strength measures the maximum stress that hair strands can tolerate when stretched.

Hair loss from breakage of the shaft is different from hair loss due to disruption of hair growth.

The studies that were conducted are similar to the studies that have been done in order to better understand traction alopecia (8). Nevertheless, the results are significant to the relationship of hard water to hair loss.

Effects of Hard Water on Hair

The 2013 study that was published in the International Journal of Trichology is about the effects of hard water in relation to the tensile strength of hair (9).

There were two samples that were tested in this study. Each sample has about 10-15 hair strands.

One sample was placed in hard water for 10 minutes and the other in distilled water in the same amount of time before their tensile strength was tested using INSTRON universal strength tester.

The procedure was done for 30 days before the researchers reached a verdict.

The result of the study shows that “hard water does not interfere with the tensile strength and elasticity of hair.”

So can we now safely conclude that hard water does not cause hair loss? Not yet.

In the same study, the researchers denoted that “if the hair is exposed to hard water for longer periods, the findings may be altered.”

Effect of Topical Application of Hard Water in Weakening of Hair in Men

Hair samples were taken from 76 male individuals from the Peshawar district (10).

Just like the previous study, the samples were divided into two groups: experimental and controlled.

The sample in the experimental group was immersed in hard water while the control group was treated with deionized water.

Both groups were then tested for tensile strength using a universal testing machine and were compared using paired t-test.

The outcome of this study is the complete opposite of the previous scientific study that we looked into.

The researchers found out that “hard water decreases the strength of hair and thus increase hair breakage.”

Evaluation and Comparison of Changes in Baseline Strength of Hairs After They Have Been Treated with Deionized Water and Hard Water and Its Role in Hair Breakage

The last study that we evaluated was done to compare changes in the hair’s baseline strength after it’s been treated with hard water and deionized water.

Unlike the previous studies, the researchers in this 2018 study divided the samples into three groups (11). Each group has 70 hair strands.

  • Group A – The control group for baseline strength of hair. The strands were not dipped in either hard water or deionized water.
  • Group B – The strands were treated with deionized water for 10 minutes on alternate days within a span of 3 months.
  • Group C – The strands were treated with hard water for 10 minutes on alternate days within a span of 3 months.

Strands from Group B and Group C were tied to glass rods, and stored in a room with a temperature of 22°C ± 3°C.

All the hairs from the three groups were then tested for their tensile strengths using a universal testing machine.

The study showed that there is a “significant decrease in strength of hair when baseline strength of hair was compared with strength of hair treated with hard water as compared to strength of hair with deionized water.”

The researchers believe that “the use of hard water may result in an increase in hair breakage as well.”

Different Hard Water Hair Loss Remedies

If you’re concerned about the possible damaging effects of hard water to your hair, there are effective ways that you can do to counteract its effects.

Browse our list of hard water treatments below.

Hard Water Hair Products

This is the easiest and simplest way to strengthen hair follicles and remove hard water mineral build-up.

Remember what we mentioned earlier about the ugly scale deposits on your cookware? Imagine that on your scalp and hair.

Those can dry up your scalp and irritate your hair follicles. You can use any of these hair products to prevent that:

Hair Follicle Stimulating Shampoo

When it comes to combatting the effects of hard water, the best way to go about it is to start at the roots. Make sure that your hair follicles are strong to prevent excessive shedding.

Start with a hair follicle stimulant shampoo. It contains 6 ingredients that strengthens, protects, and nourishes the hair from follicles to shaft.

It even has apple cider vinegar—a popular natural remedy in removing hard water minerals whilst hydrating the hair and maintaining an optimum pH level.

Shampoos and Conditioners with Chelating Agents

The metal ions in hard water can damage your hair through oxidation.

Shampoos and conditioners with chelating agents protect your hair by acting as a barrier between your hair and the metal ions.

Not only that, chelants will strip off hard water impurities that have been clinging onto your strands for a long time.

Argan Oil

Argan oil is known to offer a host of benefits—from protecting your hair from hard water mineral build-up to fighting hair loss by keeping your strands and your scalp in healthy condition.

Argan oil is safe to use on a daily basis. Simply warm a generous amount of argan oil between your palms, then apply it all over your hair while it’s still damp.

Apple Cider Vinegar

Spraying apple-cider-vinegar-and-water mixture is a cost-effective option in removing mineral build-up, keeping the scalp healthy by destroying the bacteria that harms the follicles, maintaining the pH balance of your hair, and improving scalp circulation (12).

Place 1/3 cup of apple cider vinegar into a clean spray bottle. Next, pour 1 liter of distilled water into the bottle. Cover the bottle and shake it well.

Spray your entire hair and scalp with the mixture. Massage it thoroughly into the scalp for a minute or two. Leave on for 5-8 minutes before rinsing it off with distilled water.

Baking Soda

Just like apple cider vinegar, baking soda is a safe and effective multipurpose agent. One of the most popular ways it’s being used today is as a clarifier for scalp and hair build-up.

To create a baking soda rinse, put 2 cups of distilled water in a jug then add 2 tsp. of aluminum-free baking soda. Stir the mixture before pouring it over your head.

Rub the mixture thoroughly as you would when using shampoo. Let it stand for 3 minutes then rinse it off with distilled water.

Water Softener System

Water softeners turn hard water into soft water by removing calcium and magnesium.

Once the hard water enters the mineral tank, those minerals are replaced with potassium and sodium.

A water softener system is effective in removing calcium and magnesium from your water supply, but its steep price tag makes it an impractical solution.

But if you’re willing to invest in a water softener, choose one that has a large capacity and can automatically start a regeneration cycle.


There is a possibility that hard water contributes to hair loss. However, the study of hair loss—as is every scientific study—can’t be obtained in a single linear method.

There has to be a series of studies before we can identify the key role that hard water plays when it comes to hair loss.

Science is very dynamic. It’s always a work in progress. And that’s a good thing because continuous research will foster better hair loss innovation.

In fact, we eagerly look forward to future studies so that we can use the data to provide you with the best hair loss solution.

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