When you drink this potion, you gain a Flying Speed equal to your Walking Speed for 1 minute or you can hover.

If you're in the air when the potion wears off, you fall unless you have some other means of staying aloft.

Peering into the clear potion vial, you see that the liquid inside is equally clear, though of a fizzier consistency than water. As you handle it, the gases inside form up at the top of the vial’s neck, resembling clouds moving in high wind.

I Drink an Potion of Flying
The potion threatens to fly away as I uncap it, its contents more like mist than liquid. I simultaneously inhale and slurp the contents before they can escape me, then stymie a belch. As I do, I feel my feet rise from the ground.