The longer the rats drank stevia before getting pregnant, the longer their pregnancies lasted, they had fewer babies, but the babies they did have were heavier at birth.

When female rats drank stevia water from a young age, they had trouble getting pregnant, had fewer babies, and had more girl babies than boy babies.

When female rats drank stevia from a young age, they had trouble reproducing, acted differently around other rats, and seemed less scared — which makes scientists wonder if it’s safe for growing animals.

Even though the stevia-drinking rats ate and drank the same amount as others, they weighed less during mid-pregnancy.

Rats that drank stevia didn’t prefer male rats as much, seemed less nervous in new places, but were more cautious and took longer to explore.