The most commonly reported side effects of letrozole include fatigue, nausea, and neutropenia, based on 61,870 FDA adverse event reports from 2004 to 2025.
Percentages show how often each reaction appears relative to total reports for letrozole.
These are voluntary reports and do not establish that letrozole caused these reactions.
Report severity
Seriousness is determined by the reporter, not by OpenClaim.
Other drugs that appear in adverse event reports alongside letrozole. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.
Also suspected
Taken alongside
Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.
91.9% of letrozole adverse event reports involve female patients and 1.6% involve male patients. The largest age group is adult at 51%. These figures reflect who reports side effects, not underlying risk.
Sex
Age group
Conditions and purposes for which patients were taking letrozole when the adverse event was reported.
Showing 15 of 704 indications
Letrozole is sold under the brand name Femara.
An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.
Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.