A parasite cleanse before a flush is not necessary and many people have successfully flushed without doing any type of preflush parasite cleanse. I have done both a flush with a preflush parasite cleanse using clarke's parasite zapper and one with no preflush parasite cleanse. I noticed no difference what so ever. The Liver Flush by it's very nature should lead to the death of many parasites and their elimination from your system.