It is generally safe to take Tylenol and Advil while breastfeeding. However, it is important to be cautious with medications that contain pseudoephedrine, as it can potentially affect your milk supply or disrupt your baby's sleep. It is recommended to use saline solutions for nasal congestion, such as Hydrasense or Sinus Rinse. If you do choose to take Tylenol Cold and Sinus, monitor any changes in your milk production or your baby's behavior, and stop taking the medication if needed. It is always best to consult with a healthcare professional before taking any medication while breastfeeding.