Biologic medicines have revolutionized the treatment of many serious disorders. Biosimilars offer similar safety and efficacy at a fraction of the cost, though while they have led to significant savings, uptake varies globally due to concerns and regulatory inconsistencies, especially in middle-income countries where the need for affordable drugs is greatest. 'Fast Facts: Biosimilars: A Global Perspective' has taken a specifically global perspective, with expert contributors invited to represent a range of medical specialties, including endocrinology, hematology, oncology and immunology, and regions of the world. It addresses the following concerns, drawing on the most up-to-date information in this fast-moving area of medicine: Is the quality of the biosimilar medicine equivalent to that of the original drug? Is the biosimilar medicine safe? Which indications can the biosimilar medicine be used for? What are the realistic economic benefits? How do I switch a patient from a biologic to an equivalent biosimilar medicine? How do I select biologics in a region with regulatory uncertainty over biosimilars? How do I explain biosimilars to patients?