https://twitter.com/gidmk/status/1422044335076306947 is probably the best source on this. GidMK has made something of a name for himself debunking this stuff, for better or for worse. If you want a source that's not associated with him but still critical, though not as detailed, you can check:

https://ebm.bmj.com/content/early/2021/05/26/bmjebm-2021-111...

There's also Scott Alexander's detailed writeup, which I found good reading.

https://astralcodexten.substack.com/p/ivermectin-much-more-t...

It has been criticized for relying too heavily on GidMK, but in my opinion that's reasonable - he is in fact the expert who has studied this in detail.