A choice will have been made based primarily on the route of administration of the product, either intravenous, (through your veins) or subcutaneous (through your skin) and the availability of that product in your area. The source plasma is the sa me, and most products are “fractionated” (separated out from) plasma by the same methods and have the same viral inactivation and safety steps. The key differences are often in the stabilizing agents (sugars or proteins) and concentration (which affects infusion times). Some individuals may react to a given product or batch, but this rarely requires a product change.