Ruge is the daughter of an engineering professor and visited the Ina-Seidel-Schule in Braunschweig. Her sister Annette is an aeromedical doctor at the European Aviation Safety Agency in Cologne. After finishing high school at the age of 17 she studied biology and German language and literature at the TU Braunschweig to become a teacher. She passed her final exams with distinction.

Nina Ruge has also been an entrepreneur since 2020. Together with her husband, top manager Wolfgang Reitzle, and Swiss billionaire Michael Pieper she has invested in the biotech startup Tomorrowlabs GmbH. The company, which was founded in 2016 in Vienna by the physician Dominik Duscher and pharmacologist Dominik Thor, is based on the patent-pending HSF ("HIF strengthening factor") active ingredient, which is supposed to promote skin and hair regeneration. Together with Duscher, she published in 2020 her 25th book: Altern wird heilbar (Curing Aging), a German bestseller.