Prior research has demonstrated that high processing fluency influences a wide range of evaluations and behaviors in a positive way. But can high processing fluency also lead to potentially hazardous medical behavior? In 2 controlled experiments, we demonstrate that increasing the fluency of pharmaceutical drug names increases drug dosage. Experiment 1 shows that drugs with fluent names are perceived as safer than those with disfluent names and this effect increases drug dosage for both synthetically produced and herbal drugs. Experiment 2 demonstrates that people chose a higher dosage for themselves and for a child if the drug bears a fluent (vs. disfluent) name. Using linear regression based mediation analysis, we investigated the underlying mechanisms for the effect of fluency on risk perception in more detail. Contrary to prior research, we find that affect, but not familiarity, mediates the fluency-risk link. Our findings suggest that a drug name’s fluency is a powerful driver of dosing behavior.