Can Hard Water Cause Hair Loss? (According to Science)

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You’ve probably heard that showering in hard water has various unwelcome effects on your hair. But how much of this is rooted (pun intended) in fact? And how much is simply scaremongering in an attempt to encourage you to buy a water softening solution?

We’ve shared the answer to the question – “Does hard water cause hair loss?” – based on evidence from data-backed studies available today.

πŸ“Œ Key Takeaways:

  • Some studies suggest that hard water may have effects leading to hair loss, while others have found no link between hard water and hair loss.
  • A few other potential effects of hard water include hair thinning, dry hair, and reduced style retention in bleached hair.
  • You can protect your hair from the effects of hard water by using clarifying treatments and installing a water softener.

πŸ€” Hard Water And Hair Loss: Is There A Link?

From the scientific research we’ve read online, hard water doesn’t specifically cause your hair to fall out. But it may cause your hair to take on qualities that prevent further growth and damage your ends, resulting in poorer-quality hair.

We do know for certain that hard water forms soap scum deposits on the hair follicles, preventing them from absorbing moisture, which can result in dryness, breakage, and damaged hair – all factors that can contribute to a lack of hair growth.

hard water and hair loss

🚱 What Is Hard Water?

Before we look at the research into hard water and hair loss, here’s a quick overview of hard water.

Hard water is water that has a high concentration of calcium and magnesium minerals.

These minerals are found naturally in most water supplies, including over 80% of the drinking water supplied to homes in the US.

While hard water isn’t dangerous, it does have several known effects in the home, including scale formation and mineral deposits.

Some people choose to install a water softening system to produce softened water at home, which eliminates the water quality effects of hardness minerals.

πŸ“– Studies For And Against Hard Water Causing Hair Loss

Let’s take a look at a couple of studies into the effects of hard water on hair, specifically pertaining to hair loss.

Study 1: Hard Water Doesn’t Affect Hair Strength Or Elasticity

The strength of your hair strands is associated with your likelihood of losing hair. The stronger your hair, the more it’ll withstand brushing, and the less likely you are to experience hair loss.

Your hair’s elasticity also affects your likelihood of hair loss. If your hair strands have high elasticity, they’re more pliable, which means hair is easier to style and less likely to snap and form split ends.

One 2013 study compared the effects of hard water vs distilled water (pure water containing no minerals, salts, chemicals, or other contaminants) on tensile hair strength and elasticity.

The study found that hair washed in hard water had a mean tensile strength of 105.28 and a mean elasticity of 37.06, while hair washed in distilled water had a mean tensile strength of 103.66 and a mean elasticity of 36.84.

So, the tensile strength and elasticity of hair washed in distilled water was actually slightly lower than hair washed in hard water.

What does this tell us? Hard water doesn’t cause hair loss as a result of a reduction in hair strength and elasticity.

Showering with hard water

Study 2: Hard Water DOES Affect Hair Strength

Another study, this one conducted in 2018, also looked at the effects of hard water on hair’s tensile strength.

This study had the opposite outcome – finding that men who washed their hair in hard water saw a decrease in hair strength compared to the baseline strength. On the other hand, men who washed their hair in deionized water (water containing no mineral ions) saw less of a significant decrease in hair strength.

The study concluded that the findings suggest that hard water is likely to increase hair breakage and shedding due to its association with decreased hair strength.

However, it also noted that the results may be different for females, and with different levels of water hardness and different sample sizes.

In conclusion, it’s difficult to say for certain whether or not hard water can affect hair strength and elasticity significantly enough to cause hair loss.

More studies need to be conducted for us to get a clear understanding of how hard water might increase the likelihood of hair loss in this manner.

πŸ”Ž How Does Hard Water Affect Hair?

There’s contesting evidence about hard water’s ability to decrease hair strength and elasticity in relation to hair loss.

But what do we know about the general effects of hard water on hair?

Again, there are numerous studies that look more generally at hard water and hair quality, and they don’t all have equal findings.

We’ve highlighted a few potential effects of hard water on your hair below.

Decreased Hair Thickness

One 2016 study looked at the thickness of hair treated with hard water compared to hair treated with soft water.

The study found that the hair trends treated in hard water were ruffled in appearance and had a decreased thickness compared with hair treated in distilled water.

This tells us that hard water may play a part in hair thinning and other forms of hair damage, even if it doesn’t all-out lead to hair loss.

Dry Hair

The same study mentioned above noted that the hard water-treated hair also had noticeable mineral build-up on the surface.

When hardness minerals accumulate on the hair, they reduce the hair’s ability to absorb moisture from shampoos, conditioners, and the other products in your hair care routine.

As a result, you’re left with dry, brittle hair that may look dull and limp because it isn’t properly benefiting from your hair treatments.

Hard water and hair dryness often go hand-in-hand.

Woman with straw-like hair due to hard water

Reduced Style Retention In Bleached Hair

If you have bleached hair, hard water might affect your hair’s styling retention, according to this 2011 study.

The study found that hard water actually improved the styling retention of virgin (unbleached) hair, while it significantly reduced the styling retention of bleached hair.

🩺 Other Claims About Hard Water Hair Effects

The above effects of hard water on hair are all backed by various studies – even if the data is admittedly limited so far.

There are plenty of other claims that various hair care and water softener companies have also made about the effects of hard water on hair.

According to these companies, hard water can:

  • Alter hair color or cause hair color to fade (particularly for color-treated hair)
  • Cause greasy hair
  • Increase dandruff
  • Cause knotty, tangled hair
  • Prevents effective hair cleansing

These claims might be true, but we struggled to find any scientific evidence or research data to support them.

Continue Reading: Can hard water cause dandruff?

πŸ‘¨β€βš•οΈ How To Protect Your Hair Against The Effects Of Hard Water

Here are our two recommended methods of protecting your hair against hard water damage.

Use A Clarifying Shampoo

The best way to avoid or remedy the potential effects of hard water on your hair is to use a clarifying shampoo.

Washing your hair in this type of shampoo should remove excess residue or hair build-up, including soap scum produced by hard water minerals.

While clarifying shampoo won’t prevent further mineral buildup, it should prevent dryness and help your hair to better retain moisture by washing away the soap scum.

Some websites also recommend washing hair with natural remedies, like apple cider vinegar or lemon juice, which might help – but we recommend speaking to your hairdresser before putting anything potentially irritating on your hair and scalp.

Woman using a clarifying shampoo

Install A Water Softener

The only way to properly address the effects of hard water on your hair is to eliminate the calcium carbonate and magnesium minerals from your water.

You can do this with a soft water system, or a water softener.

Water softeners exchange hardness mineral ions with sodium ions, preventing water from forming calcium build-up.

If you’re concerned that calcium and magnesium might be affecting your hair growth or causing any other sort of hair damage, you can eliminate this potential by removing the minerals in question.

πŸ’‘ Note: Most shower filters CAN’T remove hardness minerals or prevent mineral deposits. Only buy a shower filter if your main priority is chlorine removal. If you want to shower in soft water, you need a whole-home water softener.

Springwell WSS well wate filter and salt based softener combo system

πŸ“‘ Final Word

A number of companies selling water softeners and softening shower products are quick to tell you that hard water will cause significant hair loss. But don’t be so quick to believe it.

It’s clear that hard water can damage hair and reduce new growth, and might also cause breakage and split ends at the bottom of your strands. But there’s no evidence to suggest that hard water will cause your hair to fall out, or anything so dramatic.

In short, showering in hard water is bad for your hair and will affect its ability to retain moisture, so your luscious locks may start to feel dry and dull.

If you want to avoid damaged hair from hard water mineral build-up, you can try to remedy this damage with leave-in conditioners and hair masks, or consider installing a water softener in your home.


Does hair loss from hard water grow back?

If your hair loss was specifically caused by hard water, it should eventually grow back once you start washing solely in soft water. Keep in mind, however, that there’s limited evidence to suggest that hard water does cause hair loss, so your hair fall might be caused by another lifestyle factor, including your diet, hormonal changes, genetics, and age.

How do you know if your hair is falling out from hard water?

There’s no way to know for certain whether or not hard water is to blame for your hair loss. But you can narrow down the possibilities. Have you used hard water all your life? If so, it’s unlikely that any recent hair fall is caused by showering in hard water. Also consider whether you’ve made any recent changes to your diet, whether you’re going through any stress, or whether you have any symptoms that could point to a specific medical condition.

Does water softener help with hair loss?

A water softener might help with hair loss by removing calcium and magnesium minerals from water, preventing soap scum and thinning, which could make hair brittle and more prone to breakage. However, a water softener won’t prevent you from losing your hair if your problem is caused by another unrelated lifestyle factor.

  • Laura Shallcross
    Senior Editor

    Laura is a passionate residential water treatment journalist who holds an undergraduate degree in Print Journalism and a master’s degree in Creative Writing. Over a span of 5 years she's written on a range of topics including water softening, well water treatment, and purification processes.

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