The nocebo effect is a non-pharmacological effect causing a negative subjective outcome on treatment, which cannot be objectivised. It is a known but often disregarded phenomenon, impacting patient outcomes across different therapy areas.

Specific areas of nocebo-related research focusing on reference biologic to biosimilar biologic switching has rekindled interest in the nocebo effect and its clinical implications.

A lack of knowledge regarding biosimilars is causing reticence to switch; improving communication strategies when transitioning patients to a biosimilar may improve clinical outcomes and discontinuation rates. A coherent approach across the full healthcare team is required to realise the cost-saving potential of biosimilars.