Dexal Sport Nutrition magnesium effervescent tablets contain magnesium, which contributes to normal functioning of the nervous system and muscles and normal energy-yielding metabolism and electrolyte balance. Magnesium also contributes to a reduction of tiredness and fatigue. The upper limit of the safe daily intake of magnesium is 250 mg. The amount of magnesium obtained from this product in a daily dose (375 mg) exceeds this amount. Not for children, elderly, pregnant or lactating women.