A biosimilar is a highly similar product to the original biologic medication already approved by the Food and Drug Administration (FDA). Biosimilars are made with the same types of natural products and administered in similar ways. Biosimilars have the same effectiveness and safety as the original biologic and therefore have no clinically meaningful difference. In most cases, the biosimilar is made using a different production process and this makes it not identical to the original product.

Using biosimilars has been associated with decreased costs and increased therapy options for patients. Although biosimilars are not interchangeable without permission from the prescriber, more and more patients are requesting biosimilars due to lower copays associated with preferred products.