Recent studies claim that dietary supplements could contain pharmaco-active ingredients or undeclared drug substances with a potential health risk. Most often these products are contaminated with anabolic steroids, ephedrine, sibutramine, diuretics and others. The intake of a contaminated dietary supplement could lead to serious health consequences (the pharmacological effect of the substances, side effects, drug interactions and many others) or other negative consequences like failure of a doping test (for professional athletes). We have performed HPLC screening for furosemide. Measurements were performed at 228 nm at a flow rate 0,8 ml/min. The mobile phase was composed of methanol and water in a ratio 80: 20 (v/v). The pH of the mobile phase was 3,3 adjusted with Phosphorous acid. Chromatographic column - Microsorb-MV 100-5 C18 150 × 4.6 mm. We have analysed 30 food supplements in the category”prostate health”. We have found undeclared furosemide in 10% of the samples.