With serious adverse drug reactions being a leading cause of death, we assessed the potential impact of pharmacogenetic testing on patient health. Every person tested had at least one actionable variant and 10 drug-gene interactions on average. We found that millions of prescriptions are potentially affected by pharmacogenetics every year. These results indicate that drug therapy decisions should include pharmacogenetics. Informing prescriptions with pharmacogenetic information can save lives, decrease adverse drug reactions, and improve symptom relief.