Magnesium oxide is widely used in the industry because it is cost-effective and contains a high proportion of elemental magnesium per gram, but it is considered one of the less absorbable forms – its estimated absorption is around 4%, compared to magnesium citrate, malate or bisglycinate, which have significantly better bioavailability (Koc et al., 2025; Merschmann et al., 2025). The stated dose of 350 mg on the label is therefore nominally high, but the actual contribution to the body's magnesium stores is likely lower than it would be with the same dose in an organic form. If magnesium effectiveness is particularly important to you, consider a supplement with a different form of this ingredient.

The manufacturer explicitly advises on the label that individuals with high blood pressure consult a doctor before use, which is sensible to follow. The product contains sodium (230 mg), potassium (300 mg) and chloride (626 mg) per dose, and these minerals can affect fluid balance and the action of blood pressure medications, especially diuretics. Since hypertension is a condition where careful monitoring of electrolytes is important, we recommend discussing regular use of this product with your doctor, who is familiar with your treatment.

Unfortunately not entirely – MultiSalt capsules are made from gelatin, which is of animal origin (usually beef or pork), so the product is not suitable for vegans or strict vegetarians who avoid all animal ingredients. If you're looking for a gelatin-free electrolyte supplement, AdvancedU also offers other products from the same category (for example, in powder or tablet form without a gelatin shell) that are more suitable for a vegetarian or vegan diet.

The manufacturer primarily recommends the product for high-intensity physical activity involving significant loss of water and electrolytes, so it is not necessarily intended for daily use regardless of activity level. During a moderate daily routine without heavy sweating, the body usually regulates electrolytes well through a balanced diet, and additional intake is not necessarily needed. We also point out that electrolyte replenishment is not meant to replace an adequate intake of plain water throughout the day (Rangan et al., 2021).