Eco-Test examines magnesium supplements: Overdose and inadequate labeling

Jun 8, 2026 - Foods

Eco-Test examines magnesium supplements: Overdose and inadequate labeling

In the current Öko-Test issue (06/26), 28 dietary supplements with magnesium were examined, yielding a critical result: every second product is overdosed. Many supplements exceed the maximum recommended daily intake of 250 mg of magnesium from dietary supplements recommended by the Federal Institute for Risk Assessment (BfR). Some products contain up to 400 mg per daily dose. Excessive magnesium intake can cause diarrhea, nausea, vomiting, and in severe cases, cardiovascular issues. It is particularly problematic when the entire daily amount is contained in a single tablet or capsule, making it difficult for consumers to reduce the dosage sensibly.

Additionally, Öko-Test criticized the product declarations. Several supplements lack important warnings, for instance, regarding simultaneous medication intake or the necessity of medical clarification in cases of suspected magnesium deficiency. Some manufacturers also convey the impression that daily stress quickly leads to magnesium deficiency. Some products are even recommended for children and adolescents without indicating that the reference values provided apply only to adults. This further increases the risk of overdosing.

According to Öko-Test, magnesium supplementation is generally unnecessary for healthy individuals, as the requirement is usually met through a balanced diet. Those who still wish to take magnesium should ensure an appropriate dosage and transparent product labeling.

In our Tentamus labs, we conduct examinations of dietary supplements. We provide fast and reliable results and are happy to advise you on all matters related to product safety. Our customer consultants are available for any inquiries.

Source: