Nanotek chitosan?

I have a friend who has lyme and he  gave me this bottle of nanotek chitosan. I have never taken it but I am curious about your thoughts or experience. it is made out of crab, shrimp and lobster which I find intersting because the crab and lobster help me with my pain if i eat it. It is suposed to support enhanced detoxification of Herxheimer's reactions also known as die off. Any exeprience with this? It sounds very soothing to me if there aren't any shellfish allergies?