Synergy quantifications to identify individual contributions of combination partners to the overall activity - The example of STW 5.

Background: The rationale of combinations of plant extracts is often questioned. The common argument for combinations is a higher efficacy of the combination partners by multitargeting and the elimination of adverse events.

Aim: STW5, a well-known fixed herbal multicomponent preparation, is recommended in the German treatment guidelines for functional gastrointestinal diseases.