When I travelled to Mexico, I took ivermectin as COVID prevention. According to the guideline set by flccc.net , each time I took 12mg, twice per week, for two weeks.
I was in super crowded subway car over there, where the distance of my nose is only 30cm away from some other's. Turned out to be without medical accidents.
No adverse side effects were noticed.
No positive side effects either.
In Mexico, you can buy ivermectin freely in any pharmacies. No prescription is required. There are two brands, with different prices. The cheaper one works out to be about CAD$8 for 24mg.