Thalassothérapie (French Seawater Cure)

Heated seawater (pumped from at least 300m offshore) carries higher mineral concentration than bath salts. Treatments use a mix of immersion, pressurised jets (affusion), marine-mud wraps, and algae applications. The warmth increases blood flow, minerals are absorbed (controversially — some studies suggest only magnesium and iodine cross the skin meaningfully), and the protocol itself forces rest.

A 3–6 day cure is standard. Mornings are treatment blocks (2–3 hours of alternating hydrotherapy, wraps, massages), afternoons are rest. Expect fatigue the first two days as the body decompresses, followed by noticeable softening of skin, reduced muscular tension, and sleep improvements by day 3.

Thalassothérapie is a 19th-century French invention (the word was coined in 1865 by physician Joseph La Bonnardière) that built an entire industry along the Breton coast. Practitioners immerse patients in heated seawater at 33–35°C for 20 minutes at a time, supplemented by seawater hydro-jets, seaweed wraps, and marine-mud applications. The theory: magnesium, calcium, iodine, and trace elements cross the skin barrier through warm water; clinical literature is mixed but real for muscle recovery, stress-related skin reactivity, and post-surgical rehabilitation. France considers it medical — some cures are prescribed and partially covered by French health insurance. The Brittany and Normandy coastline is dense with certified thalasso centres.