Supplement breastmilk

Rachel

My son is 6 months (17lbs 10oz) & up until now he is EBF. I pump his bottles for daycare but I'm starting to get behind & I'm not able to power pump to increase my supply due to my schedule. What is a good formula that can be recommended to supplement his bottles? He also eats solids so I want something that wont cause him to get constipated. My goal is to breastfeed until he is a year but I need the formula as a supplemental backup.