FC Nürnberg in 2016–2017, playing 14 games with the reserve squad and 11 with the primary club in 2.

[5] Over the ensuing three seasons, Lowen alternated between games for Hertha BSC and their reserve squad, and loans out to Bundesliga clubs FC Augsburg in 2020 and VfL Bochum in 2021-2022.

In week two of the 2023 season, Löwen was named to the league's Team of the Matchday after scoring the game-winning goal in a 3–1 victory over Charlotte FC.

[12] Despite those games missed, Löwen was a finalist in MLS' Newcomer of the Year voting, finishing third behind Lionel Messi and winner Giorgos Giakoumakis.

[14] Löwen is married, and he took an extended leave of absence during the 2024 MLS season to be with his wife, Ilona, as she underwent treatment for brain cancer.