Nutraceutical: A food or part of a food that allegedly provides medicinal or health benefits, including the prevention and treatment of disease. A nutraceutical may be a naturally nutrient-rich or medicinally active food, such as garlic or soybeans, or it may be a specific component of a food, such as the omega-3 fish oil that can be derived from salmon and other cold-water fish.

Reference: by William C. Shiel Jr., MD, FACP, FACR,https://www.medicinenet.com/script/main/art.asp?articlekey=9474#healthy_diet_facts,july 5th,2019

For migraine Nutraceutical, you can have a look at the following post: https://migrainecanada.org/2015/08/30/are-there-natural-products-that-can-help-with-migraine-prevention/