What can I take for seasonal allergies while breastfeeding?

During breastfeeding, it is safe to take antihistamines such as Aerius and Claritin for seasonal allergies. It is also recommended to use saline water to irrigate the sinuses, avoid keeping windows open when allergen levels are high, and change clothes after coming back from outside. Biotin found in multivitamins is considered safe while breastfeeding, but collagen's safety is uncertain so it is best to avoid taking it during breastfeeding. Remember to consult a healthcare professional for personalized advice.