Patients often use dietary supplements for cardiovascular prevention. An US study showed that 75% of patients with cardiovascular disease used dietary supplements. Red yeast rice, phytosterols and fibers can significantly decrease LDL. The level of monacolin in red yeast rice can vary between products and toxins can sometimes be found. Prospective studies showed that fibers could decrease cardiovascular risk. Others substances, like guggul, soy and artichoke leaf extracts, did not show a clear benefit for cardiovascular prevention. Measurements of cholesterol levels can help the physician to discuss with his patient about the effects of some dietary supplements.