S.H.
Yes you can mix it. The other suggestions are great.
One other comment....your baby is 5 weeks old. Since you are not producing enough milk, yes you need to supplement. Don't wait too long though... when a baby does not have enough intake (in quantity and calories)...they can get dehydrated and it can affect their growth & development as well. So look out for that. Your little one does seem to be gaining weight though, so that's good. Also, be sure you breastfeed long enough so the baby can get to the hind milk. Use both breasts per session as well... i had to do that with my boy who nursed voraciously... versus alternating breasts, 1 boob per session wasn't enough. Using both breasts may increase your flow.
Are you producing only 1 oz. per feeding because you pumped it and measured it??? Sometimes with pumping, not as much comes out... versus breastfeeding. (it's 2 different "sucking" methods). I was that way too. But, my Pediatrician said no worries, in my case, because both my babies were in the 90th percentiles. So I only breastfed and didn't pump... and both my children grew like weeds too. So... perhaps you are actually producing more milk than you may think?
In either event, it's best to check. Perhaps see a lactation consultant.
Good luck and take care,
~Susan
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