The maker of Poligrip denture cream will stop making formulas containing zinc, doing so while there are pending lawsuits alleging that years of excessive use caused neurological damage and blood problems in consumers.
Glaxo's voluntary action comes as the cases are moving through the lawsuit phase, alleging Poligrip caused nerve damage, leading to a loss of balance, loss of sensation in hands and feet, and leaving some patients paralyzed.
Even though zinc is a very essential requirement for a healthy body, excess zinc can be harmful, and cause zinc toxicity. Excessive absorption of zinc can also suppress copper and iron absorption. The free zinc ion in solution is highly toxic to plants, invertebrates, and even vertebrate fish. The Free Ion Activity Model (FIAM) is well-established in the literature, and shows that just micromolar amounts of the free ion kills some organisms. Source.