Can Monacolin K be combined with milk thistle?

Yes, you can. There are no contraindications to the simultaneous use of the preparations listed in the question. However, keep in mind that monacolin K may interact with other medications, including blood pressure lowering or anticoagulants. Before using monacolin K or milk thistle for medicinal purposes, it is worth consulting a doctor. I enclose materials that may be interesting and information about the possibility of using teleconsultation: https://www.gdziepolek.pl/telekonsultacja https://www.gdziepolek.pl/artykuly/czy-przyjmowanie-kilku-lekow-jednoczesnie-jest-bezpieczne