Nutraceuticals consist of a range of substance ranging from nutritional supplements to functional foods and is utilized to any matter that improves the general welfare and lessens the danger of diseases. By the end of the twenty-first century, the use of nutraceuticals turned out to be more and more accepted in both humans as well as animals owing to their effortless right to use, profitability, and acceptability with a large scope of wellbeing. While few nutraceuticals are safe, others have lethal potential. Regardless of extensive use, there is restricted proof of health advantages associated with nutraceuticals in well-nourished adults. On the contrary, only few of these products have the prospective to preventive major toxicity. For majority of nutraceuticals, no toxicity/safety data are accessible by reason of a lack of pharmacological/toxicological examinations. The safety of a few nutraceuticals can be concession by contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, etc. This chapter describes various aspects of nutraceuticals, particularly the role of nutraceuticals in cancer, safety profile of some nutraceuticals, and genomic and proteomic models for the assessment of toxicity and safety of nutraceuticals and their toxic potential.