Since ancient times, people used various types of oils for treatments of various diseases in the form of infusions and plant extracts. Modern methods of extraction of valuable plant compounds have been developed with the advent of new research and measurement. New methods are based on solvent extraction, like carbon dioxide, which are harmless to humans and the environment. Supercritical carbon dioxide extraction takes place at low temperatures (about 30° C), whereby carbon dioxide is compressed under high pressure facilitating the penetration of the extracted material. The extracts obtained with this method do not contain inorganic substances and retain more natural active ingredients because the relatively low temperature of the process does not impair them. The herbal extracts obtained by this method are microbiologically pure as carbon dioxide will evaporate without trace throughout the whole process. The whole process takes place without air - the product manufactured does not have the ability to pass the oxidative metabolism. So now, more and more valuable polyunsaturated oils, flavonoids, anthocyanins, and pharmacology dyes can be produced. An important feature of carbon dioxide in oil extraction is selectivity which allows the isolation of bioactive substances with the simultaneous separation of contaminants, including heavy metals.