[3] In 2003, Garijo became managing director of Aventis Spain, leading the merger with Sanofi.
In 2011, she became chief operating officer of Merck Group, until being promoted to president in 2013 and elected a board member in 2015.
In May 2021, she was named chief executive officer of Merck, following Stefan Oschmann.
[4][5] In her capacity as CEO, Garijo accompanied Chancellor Olaf Scholz on state visits to China in 2022[6] and 2024.
[7] Garijo has been included in the list of "World's 100 most powerful women" by Forbes in 2023 (68th rank in 2023).