ivermectin does not cross the blood brain barrier
however fenbendazole does
that is why some folks alternate between the two
neither is definite, but are worth the chance
It can in humans and dogs who have a genetic problem with the pump . I am one of those people. I am convinced that particular defect caused problems with p-gp substrates.. I proved with Mayo clinic tests that a drug was still in my body several months later causing havoc when all the doctors told me it leaves the body very quickly.
On the flip side if I get cancer where treatment is a problem because of the barrrier I will experiment with ivermectin to see if it can help it through