"Due to its high lipophilic nature, ivermectin is extensively distributed with broad volumes of distribution (Vd)
in all species. It tends to accumulate in fat tissue, which acts
as a drug reservoir and the highest levels of ivermectin are
found in liver and fat, and the lowest in brain tissue.
Binding studies in dogs have shown that ivermectin binds
extensively to plasma albumin and lipoproteins (Rohrer
and Evans, 1990), and this should be considered in
undernourished animals or in diseases in which plasma
proteins decrease, as there would be a higher free fraction
of the drug. Ivermectin persists in the body for a prolonged
period, due not only to low plasma clearance but also to
this accumulation in fat tissue. "
Hmm, i was going off the fact it's highly soluble in fat, it will stay in the system a long time.
https://parasitology.cvm.ncsu.edu/vmp930/supplement/ivermectin_pharmocology_rev2009.pdf
"Due to its high lipophilic nature, ivermectin is extensively distributed with broad volumes of distribution (Vd) in all species. It tends to accumulate in fat tissue, which acts as a drug reservoir and the highest levels of ivermectin are found in liver and fat, and the lowest in brain tissue. Binding studies in dogs have shown that ivermectin binds extensively to plasma albumin and lipoproteins (Rohrer and Evans, 1990), and this should be considered in undernourished animals or in diseases in which plasma proteins decrease, as there would be a higher free fraction of the drug. Ivermectin persists in the body for a prolonged period, due not only to low plasma clearance but also to this accumulation in fat tissue. "