Sudafed contains pseudoephedrine, a decongestant that helps relieve nasal congestion. While pseudoephedrine can potentially pass into breast milk, it is unlikely to cause significant harm to your breastfeeding baby when used in recommended doses.
However, it's important to use Sudafed cautiously and for short durations, as prolonged use may decrease milk supply1 in some parents. If maintaining a robust milk supply is a priority for you, you may want to consider alternative decongestant options that don’t contain pseudoephedrine. Nasal sprays or saline rinses can also provide relief without impacting your milk supply.
As always, it's crucial to consult with your healthcare provider before taking any medication while breastfeeding.