This article relates the effectiveness of the European Union�s (EU) effectiveness to its international actorness in negotiations on international food standards taking place in the Codex Alimentarius Commission (CAC). Actorness is taken to result from EU competence, preference homogeneity and processes of socialisation among EU Member State representatives. In the 2009 negotiations on growth promoters for livestock, whose use the EU opposes, the Commission took the lead. It was trusted and supported by the EU Member States, but its dominant role resulted in them being rather passive. As a result, the EU�s potential to negotiate effectively in the CAC was not used in its full potential.