I took one round (6pills) of mebendazole for whipworms. Took it with whole milk for the fat which makes it work better but really didn't notice anything. I'm sure I needed to do a 2nd or 3rd round but had to twist the MD's arm just to get the one prescription. It did make me very constipated which was actually a relief for about a week from how I had been. I've been much more successful with the herbs but I'm glad I took the meds so I can say I did everything possible.