Humic acid is a collective term for different compounds obtained in the process of humification - the physical, chemical, and microbiological transformation of decaying plants. Derived from natural compounds found in humus soil, with molecules obtained from ecologically clean sources, humic acid is characterized as a loose assembly of aromatic polymers, with varying molecular weights, structural properties, and reactivity. Herbalists in Rome and China have used humic acid for thousands of years; the scientific research of its benefits began in Europe in the 18th century. This complex structure contains many nutritional phytochemical groups, and also possesses chelating properties - the ability to bind heavy metals and toxins.