My grandma used to tell me back when she had my mom, she made her formula for her because my mom was a preemie and was really small. I remember the recipe my grandma used to tell me about but with the internet today, I wanted to see if I could find it and I was pleasantly surprised that I was able to. Back when I was a kid, I thought she just came up with this baby formula recipe on her own but it turns out it was a well known recipe to mother's back then.
Now with the baby formula shortage going on, I thought I would post this in case anyone wanted to try it. It worked for my mom who was a preemie and weighed only 5lbs when she was born. And in case you're wondering I found the recipe here.
13oz. Evaporated milk
2tsp. Karo Syrup
Heat all ingredients together and let cool, then pour into bottles.
Of course today's formula is probably better and breastfeeding is best but this is a good backup in case someone needs it. It worked for my mom and she turned out just fine.