Non-rare thrombophilia (NRT) are hereditary predispositions to thromboembolism, the most severe side effect of combined hormonal contraception. In the mid-1990s, the identification of NRT stirred up a controversy over the possibility of investigating these genetic variants in women wishing to use contraception. Through a review of literature, this article reconstructs the debate over whether and how this genetic test should be prescribed as a way to reconfigure the risk visibility on pharmacological contraception. The main arguments identified concern the epidemiological, social, economic and clinical aspects of the test. In a context where the overall thrombotic risk for hormonal contraception is largely invisible, the genetic tests turn to embody the thrombotic risk itself. Those who opt for selective screening argue that a better estimation of risk implies a test prescription embed in a global medical assessment of women's individual risk. To advocates of universal or 'extended' screening, the tests are valuable tools to inform women on the thrombotic risk and, as such, appraised as a moral/legal obligation, whatever their predictive power. Risk visibility thus appears as an insightful concept to analyse a complex setting associating clinical, political, social and cultural considerations that touches upon medical power, women's responsibility and drug safety.