Not yet investigated
What we have so far
The smell of cinnamon and a real antimicrobial. Cassia carries coumarin alongside it, which is the liver risk the spice aisle does not mention.
This star is on the map because the show intends to take the question apart properly — the trials, how it is actually tested, whether the thing sold is the thing studied. That work is not done yet, and nothing here should be read as a conclusion. When the investigation is published it will appear on this page.