The national nutrivigilance scheme has collected several reports of adverse effects likely to be associated with the consumption of food supplements for athletes seeking to develop muscle or reduce body fat. These reports, and the widespread consumption of these types of products in several sports disciplines, have led ANSES to draw attention to the potential health risks. Effects that are potentially serious, primarily cardiovascular (tachycardia, arrhythmia and stroke) and psychological (anxiety and mood disorders), have been observed. The Agency therefore advises against the use of these food supplements by people with cardiovascular risk factors or suffering from heart disease, impaired kidney or liver function, or neuropsychiatric disorders, or by children, adolescents, and pregnant or breastfeeding women. ANSES also recommends avoiding the consumption of food supplements containing caffeine before and during any sporting activity, as well as the concomitant consumption of several food supplements, or their combined consumption with medicinal products. ANSES reiterates the need to seek advice from a healthcare professional before taking food supplements.