There's no evidence to support Ivermectin's efficacy on humans yet. It's shown some interesting results against cancer cells in vitro, but even if it ends up working on humans (which it might not), no one knows yet what dose would be helpful and what dose might just make things worse, what cancer situations it might or might not help with, what toxicity and side-effects it would bring, etc. etc.

Anyone who self-doses with Ivermectin for prostate cancer in 2025 is just doing amateur, uncontrolled medical experiments on themself, unfortunately. The best case would be that one doesn't end up hurting oneself.