I bought 2 bottles of ImmunFactor (5 and 7) but the lactoferrin just really bothers my colon. Long before I got lyme it did the same. I don't think its die-off. I think my colon doesn't like it. It gets very irritated and painful. I wish they didn't put the extra lactoferrin in it. It seems hard to get something pure. When I took plain 4-Life TF I had no reaction at all, yay or nay. Just nada like taking a sugar pill. I'm trying to remember another TF--not Researched Nutritionals which also has gobs of other stuff in it I don't want--and can't remember the name for the life of me. Maybe Google Desktop stored it from research some years ago. I'll try that. In any case, do you think the TF on ImmuneSupport is decent? Are there other TF's out there besides the above mentioned ones? Thanks.