can also be a source of supplement ingredients; for example, collagen may be extracted from chickens or fish. Supplements are sold in multiple doses, ranging from one time usage to entire courses. They may also be enhanced with nutrient ingredients.

In the United States, the supplement industry was estimated to have a value of $151.9 billion in 2021. There are more than 95,000 dietary supplement products marketed in the United States, and about 60% of the American adult population consumes dietary supplements,