Irishlymie, I took Cat's Claw for about a year and never had any problems with it at all. I did capsules and took them 3 times a day when I was at my peak of lyme symptoms. After I healed (or went into remission) I now take Cat's Claw but not so much for lyme but more for osteoarthritis and for diverticulitis. It is helpful for both of those. Also, if I feel a cold or I've been exposed to one of those sweet grandchildren's sicknesses, I up the dosage. It is also good for boosting the immune system.
The only side effect I got was I forgot that I had already taken my dosage and so I doubled up on my dosage and I had loose stools. Real close to diarrhea, so make sure you keep track of how much you take.