Each capsule contains 220 mg of plant tannin extracts of Acerin fruit (Acer plantanoides) and Canaigre root (Rumex hymenosepalus) which are then activated with Zinc and buffered with L-Proline. Viracin works in the same manner as Tanalbit: attaching to the outer membrane of the target cell (in this case bacteria) which disables the cell and prevents proliferation and growth. Like Tanalbit, it is non-toxic with the occasional minimal side effect of constipation and/or diarrhea. If this occurs, reduction in dosage is suggested. Viracin is designed for use in stomach and some areas of the GI tract only (it can NOT be used for venereal disease, herpes or diseases requiring intensive drug therapy). It does support the immune system during winter months as it prevents proliferation of bacterial organisms from the GI to the rest of the body.