Nature's Garden Sea Kelp 15mg15mg of Kelp Extract (Fucus vesiculosus) (plant) (Standardised to contain 1% Iodine) - 500 Tablets |. Bulking Agents (Dicalcium Phosphate, Microcrystalline Cellulose), Kelp Extract (source of Iodine), Anti-Caking Agents (Magnesium Stearate, Silicon Dioxide).