I was told you have to throw these away an hour after they've been open. Do you have to throw them…

This

if the baby drinks straight from it yes, throw it away. the bacteria from the baby will break down the nutrients.

What if it's in a normal baby bottle?

I'm almost out of formula that's all they had given me and I only have one more thing of breast milk

personally I'd follow the instructions given..I wouldn't want to have any negative results with your LO.

I'm trying to find a way to get more formula I have only two bottles left

Even if it's in a bottle. All formula will tell you after an hour to throw it away.

My hubby is gonna get some formula I forgot I pumped three bottles of breast milk lol

:)