Aside from her native German, she was fluent in English, French and Spanish.
Her father was a physician.
Carstensen, who enjoyed cult status in the theater and film scene, was always open to experiments and new things.
Member of the ensemble of the Hamburger Schauspielhaus from 1965 to 1969, noted for her leading roles in plays by John Osborne and the Lope de Vega.
Discovered for the screen by Rainer Werner Fassbinder while engaged at the Theater am Goetheplatz in Bremen. Her best known role under Fassbinder's direction was as the titular narcissistic fashion designer in The Bitter Tears of Petra von Kant (1972).