Finnish North Karelia is a region with a rich cultural history of ethnomedicinal plant use, shaped by centuries of interactions among various ethnic groups. This study identified both similarities and divergences between local Finns, Karelians war refugees, and individuals of mixed origin compared to historical records. Based on 67 semi-structured interviews, we documented the use of 43 medicinal plant taxa from 25 families, of which 31 remain in use. Notably, the number of medicinal plants continuously used in North Karelia is considerably lower than in other parts of Europe, with less than 25% of historically utilised species still in practice, which reflects the fragile state of this knowledge. Factors such as forced relocation, the loss of traditional lands, and the need to adapt to new environments might have contributed to this decline. Another influencing factor is official healthcare attitudes, which have prompted Finnish residents to shift from traditional herbal remedies to modern medical practices. Understanding the circulation of ethnomedicinal knowledge and its transformation over time is essential for identifying pathways to revitalise these practices within the framework of modern healthcare systems and cultural revitalisation efforts.