You may take acetaminophen and ibuprofen at any time during your breastfeeding schedule, but it is best to breastfeed your baby before taking medication. However, if you are on opioid pain medications (prescribed by a doctor), take it right before breastfeeding. Additionally, try to avoid breastfeeding between 1 and 2 hours after taking such medications as opioids reach maximum concentration in milk during 1 to 2 hrs after ingestion (6).