I've stopped BNM now...but it takes.4 weeks to get into their system so I'm guessing it will take a few days to come out. I've looked online for any side effects but can find nothing at all. I won't give Blue it again...I use a Homeopathic Flea/Tick Spray and put Rose Geranium on their collars so I'll just stick with them. I guess you are right..all.these herbs must do something amd Blue has a delicate stomach to.say the least. I'm going to phone BNM in the morning and see what they say. If it doesn't settle on a bland.diet for.a couple of days its Vet with a sample 😊