The inulin in Collagenius is a prebiotic that indirectly supports the immune system. However, it can cause bloating in people sensitive to fructan. In such cases, we recommend taking half a dose twice a day for 5 days. Once your body has become accustomed to fructan, you can safely switch to a once-daily dose. It may also cause abdominal symptoms and complaints if taken at the same time as other magnesium-containing products. In this case, it is recommended that you do not take the two products at the same time, but a few hours apart. The sugar substitute used in the flavoured version (sucralose or stevia) may also very rarely cause stomach upset. In this case, we recommend the flavoured and sugar-free version!