So my husband started taking prophylactically before he returned to work after cancer treatment... not sure which of my responses you read. So he was not sick prior to starting Ivermectin. His medicine was doctor perscribed.

16mg - once in the morning with just a few crackers and no other food for one hour. Day 1, Day 3, Day 7, then weekly from there.

He took his first prophylactic dose and yes middle of the night spiked a fever, headache, body aches, as you say much like the flu. Before he took the Day 3 dose we called the doctor to double check since he had "a reaction" . The doctor felt certain his body was ridding parasites and was NOT any "bad reaction" to Ivermectin. He took the Day 3 dose and more of the same but milder... then the Day 7 and the following weeks he was fine taking it.

Then he did get exposed to covid after returning to work... that sick is not at all like the flu.

Thanks for your comment hope this helps.