Does Ivermectin typically cross the blood-brain barrier (BBB) in humans, and are there conditions where this might change?

Ivermectin generally has low affinity and low permeability across a healthy BBB in mammals, due in part to the P-glycoprotein efflux pump actively transporting it out of the central nervous system. However, the barrier’s integrity may be compromised by high doses, underlying inflammation, or co-administration with P-glycoprotein inhibitors, potentially allowing it to cross.