A surprisingly large body of research has explored how PEMF works on cells and tissue of humans and animals. These mechanisms are complex, with surprisingly profound beneficial effects.
The short version of what has been discovered, is that PEMF influences the body via a number of different pathways that are already well understood.
PEMF influences the cell by improving ion pumps or electron pumps in cell membranes. This leads to a cascade of changes that causes signalling molecules to improve cell function and energy output. The cell becomes better able to return to normal effient function when stressed by any condition. The capacity to respond to stress and return to normal is called homeostasis, and is the basis of health.