Major chemicals found in marijuana are in breast milk.

This is one of those that makes a lot more sense when explained. The chemicals in question are called cannabinoids. Cannabinoids are responsible for the feeling of munchies after marijuana consumption because they stimulate appetite in adults. 

If you’ve ever seen how a baby acts after being fed, this might make a lot of sense. The reason why they exhibit symptoms similar to being “high” after breastfeeding is just because they have been drinking their cannabinoids. 

So why do cannabinoids even belong in breast milk? For two reasons. First, it helps to stimulate an infant’s appetite, guaranteeing the infant will consume a necessary amount of milk. Second, it helps to calm and relax the baby. 

If you’ve ever seen a mother breastfeed to ease her child’s crying or seen an upset infant completely relax while feeding, now you know cannabinoids are the reason why. Cannabinoids are not, however, present in baby formula, which as it turns out adds one more reason why formula is inferior to breast milk. 

(Source)