About 90% of newly discovered biologically active compounds are poorly soluble in water. The hydrophobicity of drugs and phytochemicals is the main cause of their poor bioavailability and reduced biological effect. Improving bioavailability is therefore one of the most important goals of the pharmaceutical and dietary supplement industries. As part of the APIDES project, a detailed examination of the solubility of selected natural medicinal substances from the group of polyphenols and alkaloids is planned. Natural eutectic mixtures (NADES) will be investigated as potential solvents for biologically active compounds within the APIDES project. The most famous NADES is honey. Although approximately 80% of honey consists of glucose and fructose, which are individually in a solid state, honey is still a liquid. The same is the case with other NADES systems, which are always in a liquid aggregate state. The project will develop a large number of NADES based on choline chloride (polar) and terpenoids (non-polar). By dissolving natural medicinal substances in NADES, natural formulations based on nutrients, vitamins and phytochemicals will be obtained, whereby the solubility of biologically active compounds will be increased hundreds, even thousands of times. The obtained formulations will be able to be used directly as supplements, for the enrichment of food products or as media for the solubilisation of drugs in the pharmaceutical industry.