Holland & Barrett High trength Z 15mg ( Z Gluconate ). Flavour Gluconate. Holland & Barrett High trength Z 15mg ( Z Gluconate ) x 100 tablet. Bulking Agents (Microcrystalline Cellulose, Dicalcium Phosphate), Zinc Gluconate, Anti-Caking Agents Magnesium Salts of Fatty Acids, Silicon Dioxide.