Brewer's Yeast

I have a bag of the stuff I haven't re-opened in about 3.5 months since my LO was first born. Would it be okay to still use or just get a new bag?

Reason being- we just got home from LO's 4 month checkup. There was weight gain, but not much. She assumes it's because LO is very active and is tall is the reason why weight gain was little. But she would still like me to do a few things to try and get the numbers up. So back to brewers yeast I go... 🤮

• Diaper output is on track