The Chaga tea "RETHÉ PREMIUM" now contains palo azzul, a rare herb that grows in the Chaco region of Paraguay in South America.

Palo Azul is classified as a wild-level herb, which is considered the most precious herb among herb ranks. The Chaco region, where it grows, is a particularly low-lying area, even in South America, which is said to have been the bottom of the sea long ago, and it is believed that rainwater and sea-floor components accumulated here and evaporated, resulting in an abundance of minerals in the soil. It is highly saline, and only a limited number of plants can grow there, so people rarely set foot there, and the ancient natural environment remains untouched, completely untouched by pesticides.

Generally, the harsher the natural environment in which wild herbs grow, the more they absorb the blessings of Mother Nature and the more nutritious they are. The Chaco region, where they grow, also experiences extreme temperature differences and has soil rich in minerals. Despite this harsh environment, Palo Azul grows rapidly during the dry season and is the only herb that blooms with white flowers, making it an extremely rare herb full of vitality.