You are taking warfarin or other blood thinners: Cat’s claw may increase the risk of bruising and bleeding.
You are taking drugs that are substrates of Cytochrome P450 3A4: Cat’s claw may increase the risk of side effects of these drugs.
You are taking protease inhibitors: Cat’s claw was shown to increase the serum concentrations of atazanavir, ritonavir and saquinavir and can increase their side effects.
You are taking immune suppressants: Cat’s claw may stimulate immune cells, which may make these drugs less effective.
You are having surgery: Due to the potential for increased bleeding and lack of safety data.