Exactly what parasites are we talking about here? There are a lot of different parasites that can affect human beings, and there is a different remedy for each kind of parasites. In my opinion it would be best consult your doctor, who should prescribe you some medicine that will fit your particular situation.
How do you know you suffer from parasites? We've all got some bacteria in our guts - we're kinda meant to have some. Anything else I'd wanna do what Lev suggests and get myself off to the doctors.
If you actually have parasites, you need to work with a naturopath.
There are a lot of different type of parasites. You need to figure out which type you have as the treatment method is different for each different strain.
Listen to episode #77 of evolutionary radio where my good friend and naturopath doctor Amy Kroeker comes on as a guest -> https://www.evolutionary.org/episode-77/
Her contact information is in the podcast description.