The medicinal properties of salts
Different salts have been used medicinally for thousands of years, although it is important to distinguish historical remedies and traditional practices from treatments supported by modern clinical evidence. Also, not every product called “salt” is chemically the same. Sodium chloride, magnesium sulfate, sodium bicarbonate and mineral-rich salts have different properties and uses.
Sea salt
Sea salt is primarily sodium chloride, with small amounts of other minerals.
Historically, seawater and salt solutions were used for:
- Wound and skin cleansing — diluted salt water was used to wash wounds and irritated skin.
- Gargles — warm salt water has long been used for sore throats and mouth discomfort.
- Bathing — salt-water baths were traditionally used for various skin complaints and general cleansing.
- Nasal cleansing — saline solutions have a long history of use for clearing the nose.
The modern medical version of this practice is sterile isotonic saline, which is carefully manufactured rather than simply made from household sea salt.
Salt-water gargles
A warm salt-water gargle can temporarily soothe a sore throat and help loosen mucus. It is a supportive measure rather than a treatment for the underlying cause of an infection.
Rock salt
Rock salt, or halite, is mainly sodium chloride extracted from geological deposits.
Historically it was used similarly to sea salt, particularly where inland communities had access to salt mines or brine springs.
Medicinal uses included:
- saline washes;
- gargles;
- bathing;
- preservation of medicinal preparations;
- and, in some traditional systems, preparations intended for digestive complaints.
There is no established medical advantage to ordinary rock salt over ordinary sodium chloride for most of these applications.
Epsom salt
Epsom salt is not sodium chloride. It is magnesium sulfate (MgSO₄).
It was discovered as a naturally occurring mineral-rich substance associated with the waters of Epsom in Surrey, England, from which its name derives.
Historically, Epsom salts became famous as an oral purgative/laxative. Magnesium sulfate draws water into the intestine and can therefore promote bowel movements.
It has also traditionally been added to baths for:
- aching muscles;
- relaxation;
- minor aches and pains;
- and general bathing.
However, claims that magnesium is significantly absorbed through the skin during an ordinary Epsom-salt bath are not well established. The relaxing effect of a warm bath itself may account for much of the perceived benefit.
Epsom salt taken internally should be used cautiously because excessive magnesium sulfate can cause diarrhoea, dehydration and electrolyte disturbances, and it can be dangerous in people with certain kidney problems.
Sodium bicarbonate — bicarbonate of soda
Sodium bicarbonate (baking soda) is another substance sometimes loosely described as a salt, although it isn’t table salt.
Historically it has been used medicinally as an antacid because it neutralises stomach acid.
It has also been used in some preparations for:
- indigestion;
- heartburn;
- mouth rinses;
- and skin irritation.
Modern medicine still uses sodium bicarbonate in specific circumstances, but regularly taking it for indigestion isn’t appropriate for everyone because it adds a substantial sodium load and can disturb the body’s acid-base and electrolyte balance.
Black salt / Kala namak
Kala namak, or Himalayan black salt, is a traditional South Asian mineral salt containing sodium chloride alongside sulphur-containing compounds.
It has been used traditionally in Ayurvedic medicine and other South Asian systems for digestive complaints and as part of various preparations.
Its distinctive sulphurous smell and flavour are particularly characteristic.
From a modern medical perspective, however, there isn’t strong clinical evidence that kala namak provides special medicinal benefits compared with other sources of sodium chloride.
Himalayan pink salt
Pink Himalayan salt is primarily rock salt mined from deposits in Pakistan.
It contains trace quantities of various minerals that give some specimens their pink colour.
It has become popular in wellness practices, where it is promoted for purposes ranging from mineral supplementation to respiratory treatments.
However, most of the minerals occur in such small quantities that pink Himalayan salt should not be regarded as a significant source of essential minerals. It also contains sodium and should therefore be consumed in moderation.
Dead Sea salt
Dead Sea salt is unusually rich in minerals such as magnesium, calcium and potassium compared with ordinary sodium chloride.
For centuries, the Dead Sea region has attracted people seeking therapeutic bathing.
Today, Dead Sea mineral preparations are particularly associated with skin care. Some studies have investigated mineral-rich Dead Sea bathing and topical preparations for conditions such as psoriasis and certain forms of dermatitis.
The evidence is more meaningful for symptom relief and skin care than for claims that Dead Sea salt can cure disease.
Glauber’s salt
Glauber’s salt is sodium sulfate decahydrate.
It was historically used as a purgative, meaning a substance intended to stimulate bowel evacuation.
It was named after the German-Dutch chemist Johann Rudolf Glauber, who investigated sodium sulfate in the 17th century.
Like other strong saline laxatives, it can cause substantial fluid loss and electrolyte disturbances, so historical use should not be confused with routine modern self-treatment.
Oral rehydration salts
One of the most medically important uses of salts today is oral rehydration therapy.
Oral rehydration solution contains carefully balanced quantities of:
- sodium;
- glucose;
- potassium;
- chloride;
- and other components depending on the formulation.
The sodium and glucose work together to promote absorption of water in the intestine.
This is fundamentally different from simply drinking salty water. The proportions matter, which is why commercially prepared oral rehydration salts are preferable when treating significant dehydration.
Oral rehydration therapy has become one of the most important interventions for preventing deaths from severe diarrhoeal dehydration worldwide.
Saline solution in modern medicine
Perhaps the most familiar medical salt preparation is normal saline, a sterile solution of sodium chloride in water.
It is used extensively in healthcare, including for:
- intravenous fluid replacement in appropriate circumstances;
- flushing wounds and medical equipment;
- cleaning certain wounds;
- diluting some medicines;
- nasal irrigation;
- and laboratory and clinical procedures.
Other concentrations of saline are also used for specific medical purposes.
This illustrates an important distinction between traditional salt remedies and modern medicine: medical saline is manufactured under controlled conditions, with precise concentration and sterility.
Salt and wounds: history versus modern practice
Salt water has a long history as a cleansing agent. However, applying concentrated salt directly to an open wound can be painful and may damage tissue.
Modern wound care therefore generally favours sterile saline or other clinically appropriate solutions rather than homemade concentrated salt mixtures.
The old belief that “salt kills everything” is also misleading. Salt can inhibit many microorganisms at sufficiently high concentrations, but it isn’t a universal disinfectant.
Salt baths and skin conditions
Mineral-rich salt baths have a long history in European spa culture.
People have traditionally visited salt springs and mineral spas for skin complaints, rheumatic discomfort and general wellbeing.
Today, bathing in mineral-rich water may provide symptomatic relief for some skin conditions, particularly when combined with appropriate dermatological treatment. But salt baths should not be regarded as a replacement for medical treatment.
People with eczema or very sensitive skin may also find that salt water stings or irritates their skin.
Why salt became a medicine
Salt’s historical medicinal importance comes from several genuine properties:
Preservation:
Salt inhibits the growth of many microorganisms when present at sufficient concentrations.
Osmosis:
Concentrated salt solutions draw water across biological membranes, which explains both some historical uses and the physiological importance of sodium.
Electrolyte function:
Sodium and chloride are essential electrolytes involved in nerve signalling, muscle function and regulation of body fluids.
Mineral chemistry:
Different salts—such as magnesium sulfate and sodium bicarbonate—have very different effects because their chemical compositions differ.
This is why it is misleading to talk about “salt” as though every type has the same medicinal action.
A useful distinction
Type | Main substance | Traditional/medical use |
Sea salt | Sodium chloride | Gargles, bathing, cleansing |
Rock salt | Sodium chloride | Similar historical uses; saline preparations |
Epsom salt | Magnesium sulfate | Laxative; bathing |
Himalayan salt | Sodium chloride + trace minerals | Mainly culinary/wellness uses |
Kala namak | Sodium chloride + sulphur compounds | Traditional digestive preparations |
Dead Sea salt | Mixed mineral salts | Mineral bathing and skin care |
Glauber’s salt | Sodium sulfate | Historical saline laxative |
Sodium bicarbonate | Sodium bicarbonate | Antacid and some topical/oral preparations |
Oral rehydration salts | Precisely formulated electrolytes + glucose | Treatment/prevention of dehydration |
Sterile saline | Sodium chloride + sterile water | Modern clinical and wounds healing |
The most important point
Salt is genuinely essential to human physiology, but more salt is not necessarily better for health. Excessive sodium intake is associated with increased blood pressure and cardiovascular risk in susceptible people.
Likewise, many modern claims that particular salts can “detoxify,” cure disease, remove toxins through the skin or provide extraordinary mineral supplementation aren’t supported by good clinical evidence.
Historically, however, salt’s medicinal story is fascinating because it sits at the intersection of chemistry, physiology, traditional medicine and everyday survival. The ancient observation that salt could preserve food and influence the body eventually developed into modern applications ranging from saline wound irrigation to sophisticated oral rehydration therapy.
