 This study examined the relationship between chemical structure and adverse drug reactions, ADRs. It found that certain chemical structures were associated with higher risk of certain types of ADRs. For example, typorosine and methylene groups were associated with higher rates of central nervous system, CNS, ADRs, while amides, secondary alcohols, and DI-substituted phenol groups were associated with lower rates of gastrointestinal, GI, or CNS-ADRs, or both. These findings suggest that chemical structure can be used to help inform decisions about drug selection and dosing. Further research is needed to better understand the relationships between chemical structure and ADRs. This article was authored by Daniel Austin, Kumori Bisfoss, Kaley Pollock, and others.