Answer
Breastfeeding is not recommended because tamoxifen and active metabolites can accumulate in milk and tamoxifen can suppress lactation.
Sources for this answer
- Tamoxifen 20 mg Tablets — Current selected SmPCemc · Summary of Product Characteristics
- Tamoxifen Rosemont 10mg/5ml Oral Solution — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.