Medically reviewed by Angela Sheddan, DNP, FNP-BC
Written by Our Editorial Team
Last updated 3/07/2021
Hair loss is a common issue that you could first notice while brushing your hair, looking in the mirror, cleaning your shower drain catch or simply comparing your hairline to an old photo.
While most hair loss in men is caused by male pattern baldness, other factors can also cause your hair to shed. These include stress, use of certain medications and even the methods you use to style and care for your hair.
Over the years, researchers have looked into the idea that hard water -- water with a relatively high mineral content -- can cause hair loss.
While there’s little evidence that hard water can cause hair loss, some studies have found that washing your hair in hard water may contribute to certain types of damage.
Below, we’ve looked at the science behind hard water and hair health, as well as the potential relationship between hard water and hair loss. We’ve also explained what you can do if you’re based in an area with a hard water source and have concerns about hair loss.
Finally, we’ve explained how you can treat your hair loss, whether it’s caused by hard water or factors such as male pattern baldness, stress or others.
Hard water refers to water with a high mineral content, particularly the minerals calcium and magnesium.
If you have hard water at home, you may notice spots or a cloudy, film-like texture that can develop on your dishes. You may also notice a thin film of residue when you wash your hands using soap.
Scientific research on the effects of hard water on hair is mixed. Although some studies have concluded that hard water weakens hair and changes its appearance, others have found that washing your hair in hard water has no effect on strength or elasticity.
If you have a skin condition that can cause hair loss, such as eczema or psoriasis, hard water may worsen your symptoms.
You can reduce the effects of hard water on your hair by installing a shower head that’s designed to soften your water or using a clarifying shampoo to wash your hair.
If you’re losing significant amounts of hair, hard water may not be to blame. Most men’s hair loss is caused by male pattern baldness, which can be treated using medication.
Hard water is water with a high mineral content. Water that’s hard usually has a large amount of dissolved minerals such as calcium and magnesium, giving it a different feeling against your skin than regular, low-mineral tap water.
If you’ve ever washed your hands with hard water, you may have noticed a film of residue that’s left behind when the minerals in the water react with the ingredients in soap.
The hardness of water is measured by its calcium carbonate content. Water that contains less than 60mg of calcium carbonate per liter is classified as soft. The following measurements are used to measure moderate to very hard water:
A calcium carbonate content of 61 to 120mg per liter is classified as moderately hard
A calcium carbonate content of 120 to 181mg per liter is classified as hard
A calcium carbonate content of more than 18mg per liter is classified as very hard
In addition to producing an unusual film-like feeling when you wash your hands, hard water can have a variety of other effects. It can cause a film or spots to develop on your dishes over time, as well as causing damage to home appliances as a result of gradual mineral buildup.
Water hardness can vary depending on location. Research shows that areas in the Southwest, Midwest and certain parts of the Northeastern United States typically have the highest levels of calcium and other minerals in groundwater.
Some domestic wells and water sources in other parts of the country are also affected by hard water.
Currently, there’s no research showing that hard water causes hair loss. However, some studies have found that the minerals in hard water could cause your hair to become weaker -- a change that may lead to breakage and thinning.
For example, one study published in the International Journal of Dermatology involved washing 10 to 15 hair samples in either hard water or distilled water. The hairs, which were cut into two equal lengths, were washed in either type of water on a daily basis over 30 days.
At the end of the 30 day period, the hairs washed in hard water contained a significantly larger amount of calcium carbonate. They were also approximately seven percent thinner than the hairs washed in distilled water.
It’s important to note that this study was carried out using hairs that were lost during combing, meaning the same effects may not occur on actively growing, “live” hairs.
A similar study published in the International Journal of Trichology also looked at the effects of hard water on hair health.
In this study, hair samples were collected from 70 men. The hair samples were either placed in a non-treatment control group or treated using deionized water or hard water.
At the end of the study, the hair samples treated using hard water had significantly lower levels of tensile strength than the other hairs. The researchers concluded that hard water decreases the strength of hair and increases the risk of breakage.
Although weaker hair doesn’t directly lead to hair loss, hair that’s weakened may be more likely to fall out or break off when you comb, brush or style your hair.
On the other hand, a different study published in the International Journal of Trichology in 2013 also tested the tensile strength of hair treated in hard water and concluded that hard water has no noticeable effect on hair strength or elasticity.
If you live in an area with hard water and have concerns about its potential effects on your hair, there are several things that you can do to prevent damage.
One of the most effective ways to prevent the effects of hard water is to install a water softening system.
These systems typically use an ion exchange process to replace minerals such as calcium and magnesium with sodium. This reduces your home water supply’s mineral levels and softens the water that comes out of your taps, shower head and other faucets.
Water softening systems vary in price and effectiveness. The most affordable options are fitted to your shower head to soften water as you use it. More effective water softening systems filter your home’s water through a mineral tank.
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Clarifying shampoo is designed to cleanse your hair and remove residue and buildup, including the film that can form on your hair and scalp when you wash using hard water.
You can find clarifying shampoos in most drugstores, supermarkets and pharmacies. Follow the instructions provided with your shampoo and use it as required to strip away unwanted calcium and other minerals from your scalp.
Although clarifying shampoos are effective, they may cause your hair to feel overly dry. If you’re prone to dry hair or skin, make sure to use conditioner after washing with clarifying shampoo to lock in moisture and keep your hair hydrated.
Although hard water may cause damage to your hair that reduces its strength and elasticity, it’s generally not thought of as a common cause of hair loss.
Most hair loss in men occurs due to male pattern baldness, a form of hair loss that’s caused by a combination of genetic factors and the hormone dihydrotestosterone, or DHT.
Over the course of years and decades, DHT can shrink and weaken your hair follicles, causing them to no longer produce new hairs. We’ve talked about this more in our detailed guide to the relationship between DHT and male hair loss.
Finasteride is a prescription hair loss medication that works by reducing your body’s production of DHT.
Research shows that it’s effective at preventing hair loss and, in some cases, can even stimulate the growth of hair in areas of your scalp with noticeable thinning.
For example, a five-year study carried out in Japan found that finasteride stopped hair loss from worsening in 99.4 percent of men affected by male pattern baldness. Other scientific research has found that many men who use finasteride grow back “lost” hair.
If you’ve recently noticed some of the early signs of hair loss, using finasteride can protect your hair and prevent your hair loss from worsening.
We offer finasteride online, following a consultation with a physician who will determine if a prescription is appropriate.
Minoxidil is a topical, over-the-counter hair loss medication that works by increasing blood flow to your hair follicles.
Although minoxidil doesn’t block DHT, it’s effective at stimulating the growth of your hair. In one study, researchers found that 84.3 percent of men with hair loss who used minoxidil rated it as either very effective, effective or moderately effective at stimulating hair regrowth.
As well as finasteride and minoxidil, other products may help to protect your hair and stimulate growth:
Hair loss prevention shampoo. Hair loss shampoos such as our Thick Fix Shampoo are formulated to reduce buildup, promote volume and guard your hair follicles against common sources of damage.
Biotin. Biotin is a B-vitamin that plays a role in the growth of your hair and nails. While supplementing with biotin won’t prevent male pattern baldness, products like our Biotin Gummy Vitamins can help to support thick hair, strong nails and healthy skin.
Although there’s no research showing that hard water causes hair loss, some studies suggest that exposure to hard water may affect your hair’s strength and make it more likely to break off while you’re brushing, cleaning or styling it.
You may prevent damage from hard water by installing a water softening system. Washing your hair with a clarifying shampoo may help to prevent the buildup of minerals found in hard water, such as calcium and magnesium.
When it comes to stopping and reversing hair loss, the most effective treatments are finasteride and minoxidil. We’ve talked about these and other products in more detail in our complete guide to male pattern baldness.