Extensively tested for toxicity. This is considered a very reliable test of effectiveness.
Solubility reflects how well the ingredients are absorbed by the body.
Bioactivity describes how effectively the ingredients perform in the body once they have been absorbed. Solubility was tested using the standard USP 23 Method for solubility testing. Bioactivity was determined using the lymphocyte proliferation assay which confirms whether a product is able to stimulate the proliferation of immune cells or lymphocytes. Golden Seal Root and Olive Leaf extract did not show any positive bioactivity while Sambucol showed very little. Cold-FX capsules Is used as a potent immune system stimulant.