Helping others can entail risks. Doctors that treat infectious patients may risk their own health, intervening in a fight can lead to injury, and organ donations can lead to medical complications.When helping others comes with a risk to oneself, decisions depend on the individual's valuation of others' well-being (social preferences) and the degree of personal risk the individual finds acceptable (risk preferences). Here we identify how these distinct preferences are behaviorally (Study 1, N=292) and neurobiologically (Study 2, N=154) integrated when helping is risky. We independently assessed social and risk preferences using incentivized behavioral tasks, and manipulated dopamine and norepinephrine levels in the brain by providing methylphenidate, atomoxetine, or placebo. Results reveal that social and risk preferences are independent driving forces of risky helping, and that methylphenidate-altered dopamine concentrations lead to more helping under risk because of increases in risk-tolerance rather than increased social preferences.Implications for decision-theory and drug use are discussed. Statement of RelevancePeople help others at sometimes substantial costs to themselves. What has been largely overlooked is that helping can also be risky. When treating patients with infectious diseases doctors may become infected themselves, and volunteers trying to rescue ship-wrecked refugees risk injury and drowning. Here we identify individual differences in social preferencespredicting willingness to help-and risk preferences-predicting willingness to take risks-and examine how these distinct preferences alone and in combination predict decision-making when helping comes at a risk. Findings advance theory by showing that popular off-the-shelf drugs like methylphenidate increase risky helping because they alter risk rather than social preferences.