Verträglichkeit

Verträglichkeit is a German noun describing the quality of being tolerable or compatible. Broadly, it refers to whether something can coexist with a person, a system, or other substances without causing undesirable reactions. The term is formed from verträglich (tolerable/compatible) and the noun suffix -keit. In everyday language, something is described as gut verträglich if it is easy to handle or does not upset someone; unverträglich indicates intolerance or adverse reactions.

In medicine, Verträglichkeit is commonly translated as tolerability. It denotes the extent to which a drug or treatment can be used by a patient without unacceptable side effects. Assessments focus on the frequency, severity, and duration of adverse events, patient-reported symptoms, and the impact on quality of life. Tolerability is influenced by dose, formulation, indication, and patient factors such as age, comorbidities, and concomitant medications, as well as adherence. A favorable Verträglichkeit profile supports continued therapy and an overall positive risk–benefit balance. Regulatory agencies require documentation of tolerability in clinical trials and post-marketing surveillance.

Beyond medicine, Verträglichkeit is used in nutrition and social contexts. In nutrition, it can describe how well someone tolerates certain foods or drugs taken together, for example lactoseverträglichkeit (lactose tolerance). In social settings, it also denotes interpersonal compatibility—the extent to which a person fits with others or with a group, contributing to smooth interactions. Synonyms include Gut verträglich and Verträglichkeitsmerkmal, while Unverträglichkeit denotes intolerance.