Traditional medicinal plants and herbs are commonly used for health purposes and have been extensively studied. Nowadays, dietary supplements have received particular interest worldwide as they are valuable health tools in disease management. They are relatively easy to use. Moreover, they are cost-effective compared to chemical entities obtained from synthesis. Botanicals, one of the most emerging classes of dietary supplements, are made of single herbs. They are also created by mixing different herbs from raw materials, from whole plants, or from certain parts. This includes flowering herbs, leaves, leaf exudates, fruits, berries, roots, and rhizomes.

Current methodologies enable us to isolate, standardize, and characterize fractions of medicinal plants with specific bioactivities. However, there is a need to investigate further methodologies. Nowadays, research focuses on new formulations and the health properties of dietary supplements. Moreover, dietary supplement research is progressively integrating multidisciplinary research approaches. Current and novel research includes emerging technologies such as nuclear magnetic resonance (NMR) spectroscopy, isotopic ratio mass spectrometry, multi-elemental analysis, fluorescence, near-infrared (NIR), mid-infrared (MIR), and mass spectrometry combined with chemometrics.

The aim of this Special Issue is to bring together original research and review articles discussing our current knowledge of the health effects of dietary supplements. This Issue welcomes research using multidisciplinary approaches. Submissions should include the classification and categorization of dietary supplements. Moreover, we encourage submissions investigating the quality assessment and control of dietary supplements.

Potential topics include but are not limited to the following:

• Isolation and quantification of natural products used for dietary supplements (e.g., standardized fractions, emerging technologies involving chemometrics)
• In vitro and in vivo research investigating the potential health properties of natural products used in dietary supplements
• Classification and categorization of dietary supplements
• Quality assessment and control of dietary supplements