First thing first... what are you trying to treat? Have you been diagnosed with anything? If you don't have these answers then you will need to do proper testing to find out what the problem is -this is step one. Do the Metametrix GI Effects Stool test to find out what you have. Do not trust other labs due to the differences of testing methodology.
Do not believe that Humaworm or other parasite killing formulas are capable of killing EVERY parasite. There are groupings of parasites that these will not kill. This is why it is imperative to get proper diagnoses. There could be secondary infections such as yeast or rogue bacteria that could be causing problems and it is possible that these could be the primary problem and not the parasites as you have suspected. The GI tract is a very complex organ system that can have many pathogens.