Thalassotherapy is an alternative therapy that harnesses the soothing properties of the sea. The term comes from the Greek word “thalassa,” which means ocean.

Thalassotherapy dates back to the 19th century, although people have bathed in the sea for its health benefits for much longer than this.

Today, thalassotherapy is one of the treatments people can receive in coastal spas and wellness clinics. The therapy takes different forms and can involve a combination of bathing, exercising, and using marine products, such as sea mud.

There is not much research on the benefits of thalassotherapy, but a few studies indicate it may help with some conditions, such as fibromyalgia and musculoskeletal disorders. However, it is not a substitute for medical treatment.

This article discusses thalassotherapy, its health benefits, and how it works. It also looks at related therapies.

A woman standing in the ocean up to her chest, facing the horizon, as part of thalassotherapy.Share on Pinterest
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Thalassotherapy involves the therapeutic use of seawater. It is a common alternative therapy in Europe, particularly in Germany and France. Some colleges of medicine in Europe include thalassotherapy in their curriculum.

Thalassotherapy can involve a number of practices, such as:

  • bathing or swimming in seawater
  • applying marine products, such as seaweed, mud, or sand, to the body
  • spending time near the sea
  • taking supplements that contain substances from the sea

Thalassotherapy is similar to balneotherapy, which involves bathing in mineral water from a spring. The difference between them is that thalassotherapy exclusively uses seawater.

Little scientific research has tested the effectiveness of thalassotherapy. However, proponents claim it is beneficial due to the substances seawater contains. Seawater is high in a number of minerals, such as:

  • sodium
  • chloride
  • magnesium
  • potassium
  • calcium
  • iodine

Although research is limited, a few studies suggest that thalassotherapy may have health benefits.


A 2020 study investigated the effect of aquatic therapy in a seawater pool in 62 people who had experienced a stroke. Aquatic therapy involves water exercises. The experiment consisted of 45-minute sessions on 5 days per week for 2 weeks.

Analysis of the study results indicated that the combination of aquatic therapy and thalassotherapy undertaken in a Mediterranean climate may improve:

  • pain
  • balance
  • mobility
  • certain aspects of a person’s quality of life


Older research from 2005 evaluated the effects of a combination of thalassotherapy, exercise, and patient education in 58 people with fibromyalgia. The duration of the program was 2.5 weeks. Afterward, the authors evaluated the participants at 3, 6, and 12 months.

The results showed the program produced temporary benefits between 3–6 months, but they did not last beyond this time. The effects included improvements in:

  • pain
  • tiredness
  • general health
  • physical functioning

Mental health

The 2005 study also examined the effects of the combination therapy program on participants’ mental health. While it did appear to produce mental health improvements, they were of a shorter duration and less pronounced than the physical health improvements.

Skin conditions

Climatotherapy involves temporarily or permanently relocating to a certain climate to improve health or treat a condition. When someone moves to the coast, it is also an aspect of thalassotherapy.

A 2013 study explored the effects of Dead Sea climatotherapy on psoriasis. It involved 119 people with the condition, who completed quality-of-life questionnaires at various intervals during the study.

The findings suggested that being near the Dead Sea enhances the quality of life in individuals with psoriasis and psoriatic arthritis.

Musculoskeletal conditions

Research from 2011 assessed the effects of a treatment program involving sun exposure, bathing in the Dead Sea, and bathing in mineral spring water for people with musculoskeletal conditions.

The 60 participants had a variety of conditions, including lower back pain, osteoarthritis, rheumatoid arthritis, and fibromyalgia. Data analysis indicated that the program increased vitamin D levels, which linked to reduced pain and severity of the conditions.

However, this may be largely down to the sun exposure. More specific research on the impact of sea bathing is necessary to determine if thalassotherapy helps these conditions.

According to a 2019 review, thalassotherapy can benefit health in several ways.

When a person’s skin comes in contact with seawater, the sodium and chloride can penetrate and enter the body. From there, it can affect skin cells by altering the pressure inside them, which in turn may inhibit cell death.

Air near the sea also tends to be cleaner than air in cities and lower in common allergens. This may mean that people with conditions such as asthma or hay fever can breathe more easily by the ocean.

The review added that a number of plant and animal substances from the sea have beneficial properties. For example, salmon oil and cod liver oil are sources of omega-3 fatty acids.

Some thalassotherapy programs also include other things that benefit health, such as exercise and time for relaxation. This may further explain its popularity as an alternative therapy.

Proponents of thalassotherapy claim that sea air can be beneficial. It contains tiny droplets of seawater, which people inhale when they breathe in. This may mean they ingest small amounts of minerals this way, but no research has investigated if this is true or whether it can impact health.

Thalassotherapy treatments at spas and wellness centers vary. The treatment may involve:

  • Bathing: A key component of thalassotherapy is bathing in seawater. Some treatments may also involve bathing in water that contains seaweed or sea mud.
  • Showering: People in thalassotherapy spas may also shower in seawater or fresh water that contains minerals from the sea. Practitioners may use hydromassage from high pressure jets of water to soothe muscles.
  • Skin treatments: Thalassotherapy spas may use a range of marine products in their treatments. For example, a thalasso wrap involves applying seaweed or marine mud to the body before wrapping someone in a hot blanket. A person then washes the mixture off. Therapists may also use sea salt scrubs, mud masks, or other products.
  • Exercise: Many thalassotherapy programs also include exercise, such as swimming. Aquatic exercises, such as water aerobics, may also be involved.
  • Inhalation: Thalassotherapy spas may encourage residents to inhale steam from seawater or to take in the sea air around them.

Some experts categorize seaweed supplements as a form of thalassotherapy. Examples include kelp, chlorella, and spirulina supplements.

Thalassotherapy treatments at reputable spas are typically safe. The practitioners there will have training on identifying treatments that are safe for someone. However, there are still some risks involved.

For example, bathing in the open sea or in saltwater pools can pose a risk of getting caught in strong tides or drowning. People should only swim in places where there are lifeguards to monitor people’s safety.

Bathing in hot seawater can affect the body in other ways. A long, hot bath may cause low blood pressure, fainting, or tiredness. Spending too much time in the sun can also result in sunburn if a person does not protect their skin.

Marine-derived supplements can also have some risks. The Food and Drug Administration (FDA) does not test the safety of these products before they enter the market.

It is always best to consult a doctor before trying any supplement or alternative therapy, as natural treatments are not necessarily safe. A doctor will be able to tell someone if thalassotherapy could be suitable for them.

Some therapies that are similar to thalassotherapy include:

  • Balneotherapy: This involves bathing in hot spring water, either directly in the spring itself or in a spa that uses naturally sourced mineral waters. The therapy can help manage stress-related and mild inflammatory conditions.
  • Hydrotherapy: This involves submerging part or all of the body in hot or cold water. It can include the use of equipment, such as a sitz or whirlpool bath. According to a study from 2016, hot water relaxes muscles and reduces arthritis pain, while cold water stimulates blood flow.
  • Algotherapy: This involves the use of seaweed or algae in baths, body wraps, or facials to promote wellness.
  • Halotherpay: This involves breathing in salty air from a room filled with mineral-rich salt. Although it may possibly help people with asthma and chronic obstructive pulmonary disease (COPD) to breathe better, no evidence to date supports its use as a medical treatment.

Thalassotherapy is the use of seawater and marine substances for health. Some believe its benefits stem from the sea’s plentiful content of minerals, such as sodium, chloride, and iodine. People may absorb these substances through the skin, although there is limited research on whether this helps with health conditions.

Thalassotherapy treatments may involve bathing, swimming, hydromassage, or aquatic exercise. Spending time near the sea, where the air is typically cleaner than in cities, may also benefit some people.

People should speak with a doctor before trying thalassotherapy or taking marine-derived supplements.