Black walnuts dried and ground green hull contains tannin, which is organic iodine, as well as juglandin, which is extractive matter from the juice of the green shucks of the walnut. Black walnut has been used for centuries to expel a variety of worms, including parasites that cause skin irritations such as ringworm. It oxygenates the blood, which helps kill parasites as well. Black Walnut is very effective against tapeworms, pinworms, Candida albicans (yeast infections) and malaria. It is also effective in reducing blood sugar levels, and helping the body rid itself of toxins.