Jonzac Thermal Spring Water, A Unique Water

Jonzac thermal spring water is the core ingredient for all our skincare formulas. It is drawn in Charente-Maritime from its original underground environment at a depth of 1,850 meters. Its anti-inflammatory, soothing and repairing properties have been demonstrated through various studies. This spring water is hyper-mineralized and offers one of the widest-ranging varieties of mineral salts and trace elements in existence, in addition to being isotonic.


Discovered by chance at the end of the 1970s, the thermal spring water found in Jonzac has been circulating in the depths of the earth of the Aquitaine basin since time immemorial. It is the result of rainfalls from 30,000 years ago that infiltrated into the mountains of the Massif Central and the edge of the Massif Armoricain.

These millenarian waters were gradually heated and mineralized during their tenacious journey through the geological layers of alternating clays, sandstones, sands, and dolomites, ending their slow course at the aquifer formations of the northern Aquitaine Basin.

This hyperthermal water (it’s temperature is 62°C when it is drawn) of great bacteriological purity is free of nitrates, nitrites and phosphates and is also is hypermineralized and isotonic (dry residue ≈ 7,000 mg per liter).

This water is singular, because it is necessary to borrow characteristics from several physical and chemical classes of thermal waters to define it. It is in fact sulphureous, mixed sulphated, sodium chlorinated and rich in trace elements. Numerous studies have shown that Jonzac thermal spring water has revitalizing, soothing and anti-inflammatory properties.

Accredited by the Academy of Medicine, the Jonzac thermal spa has been welcoming numerous visitors since 1986 for many afflictions related to rheumatology, ENT, and phlebology, a discipline for which the nursing staff  has observed the favorable effects of this water on skin repair.


Jonzac lies at the heart of the Haute Saintonge in Charente-Maritime, and is located 90 kilometers from Bordeaux.

In 1979, the ground was drilled and this led to the discovery of underground hot water at 65°C.

The city turned this water into an asset when it opened a spa in 1986. These troglodytic thermal baths welcome 17,000 visitors per year and rank 7th in France*.

The city of Jonzac joined Laboratoire Léa Nature to create a local partnership and since 2011, Eau Thermale Jonzac dermo-cosmetic care products made with Jonzac thermal spring water have been distributed in pharmacies, drugstores, and organic stores.

*Figures for 2019


A thermal spring water with a natural affinity for skin cells.

The skin is composed of 70% water, and rich in minerals.

Since the skin is not sealed off to its external environment, when a treatment is applied, the water in the treatment comes into contact with the water contained in the skin.

When the mineral contents of these waters are different, the natural balance of the cells can be disturbed, subjecting the skin cells to malformations. Water always moves from the less concentrated medium to the more concentrated one in order to dilute it. Water that is more concentrated in minerals than the skin will cause water loss and cell dehydration, while a less concentrated solution will cause the cells to swell and possibly burst. In both cases, the skin cells will be under stress.

Jonzac thermal spring water is isotonic, which means that its mineral content emulates that of the skin cells. Since mineral concentrations are perfectly balanced, Jonzac thermal spring water does not cause skin cells to swell or be deformed. On the contrary, this water shows a natural affinity for skin cells.

Thus, the skin benefits fully from the effectiveness of Jonzac’s certified organic and high tolerance skincare products.


Hypermineralized, isotonic, and rich in trace elements, Jonzac water differs from other thermal waters used in cosmetics due to its high content of mineral salts and a unique combination of trace elements.

Jonzac thermal water is characterized by high levels of sulfates (1,900 mg/L), chlorides (2,600mg/L), sodium (1,770 mg/L) and calcium (520 mg/L), and remarkable levels of soluble silica (29mg/L), potassium (120 mg/L), magnesium (98 mg/L), strontium (13 mg/L), boron (3,9 mg/L) and lithium (1.9mg/L)*.

These mineral salts and trace elements, and more specifically sodium and chloride ions, justify the interest of Jonzac thermal spring water in skin hydration. Calcium, magnesium, and boron are of major interest in epidermal repair. Indeed, according to abundant scientific literature, they play a significant role in the skin healing process.


Jonzac thermal spring water is naturally revitalizing, soothing and anti-inflammatory.

Jonzac thermal spring water properties are confirmed by our research and testing.

We have carried out numerous studies to identify predictive markers for the revitalizing, soothing, and anti-inflammatory properties of our thermal spring water. During these tests, Jonzac water was used alone in a cell culture medium or on explants, and compared to control samples prepared with distilled water.

These tests served to demonstrate the natural effectiveness of this spring water for healing and skin repair, for stimulating the skin’s defenses and for inhibiting inflammatory processes.

* March 2021 analysis.