In Europe, patient leaflets are supplied as an insert inside all medicine packs. Manufacturers must produce such leaflets according to a template and undertake consultation with target patient groups to ensure it is legible, clear and easy to use, before a licence will be granted. The consultation is usually completed through ‘user testing’, involving individual interviews with lay participants, with both quantitative and qualitative components. After testing, good practice is applied to address shortcomings identified, and testing repeated. The process is described using the example of a patient booklet for lithium therapy. Such testing could benefit any future US process for patient medication information.