In 1929 Consul Wilhelm Doerenkamp becomes new owner of the firm; he feels especially obligated to the ideas of the founder of the firm, and the further expansion of the firm becomes his life goal. He is responsible for modern advertising and for references in the daily press and in stores. Under his leadership the slogan "It was never so valuable as now" is introduced. He directs the firm until his death in 1972.

The Second World War interrupts the development of the firm, up to now full of successes. The factories in Cologne are turned into smoldering ruins, destroyed down to the foundations. Immediately after the end of the war, faithful employers, full of enthusiasm and led by the skilled leadership of Consul Doerenkamp, begin the rebuilding of the factory.

In 1952 Paul Gräff begins work as finance director of the firm. Open to the world under his direction, the Klosterfrau firm experiences renewed growth and finds new sources of income. New products and new employees arrive on the scene. In 1964 Paul Gräff becomes general director of the firm. In order to protect the firm against the effects of possible world crises, Consul Wilhelm Doerenkamp and Paul Gräff found numerous independent companies around the world. Paul Gräff runs the firm until the day of his death, January 14, 1997.

The plant in Cologne turns out to be too small, and consequently an extraordinarily modern plant is built in Berlin, where 45,000 square meters house production facilities and warehouses of prepared products. To this day the majority of the Klosterfrau company products are produced in Berlin.

A monument to the nun Maria Clementine Martin is set up near the Cologne city hall.

The Klosterfrau firm today, a modern company in the service of people’s health, is run on the basis of: “When the wisdom of nature is brought together with the ingenuity of science, the result is service for the well-being and health of mankind.”