Biotherm is a French skin care company owned by L'Oréal under the Luxury Products division. Biotherm was acquired by L'Oréal in 1970.

In the years 1940-50, Dr. Jos Jullien, from Joyeuse in Ardeche (France), noticed the presence of a particular substance on the surface of the thermal waters of Molitg-les-Bains. This substance is composed of thermal plankton. With Jeanine Marissal, he works on the potentials of this substance that they integrate with a cosmetic formula. Biotherm was born from this work in 1952, under the leadership of Adrien Barthélémy, owner of the Molitg-les-Bains springs.

In 1952, Biotherm launched 3 products: La Crème Triple-Usage, Biotherm Cure and Biomains. Biomains, a hands moisturizing cream, is still on the market today. In 1955, 3 years after the creation Biotherm, The New York Times noticed this new French brand: "Plankton is used as aid to beauty."

During the 1960s the brand developed several targeted skincare solutions to address specific needs, including its first sun cream and its first "slimming cream". In 1968, Biotherm introduces Bio-Buste Suractive on the market, its first "breast firming cream". Biotherm was acquired by L'Oréal in 1970. L'Oréal transformed the small French brand into an international brand by opening to the rest of Europe and entering the US market (1985) and Japan (1987).

According to Statista, Biotherm was the best-selling skin care brand in Denmark. In 2019, the company generated nearly 66.4 million Danish kroner.

According to en.wikipedia and statista