It's generally not recommended to drink an energy drink on an empty stomach.
Energy drinks contain high levels of caffeine and sugar, which can cause a rapid spike in blood sugar levels. This can lead to a crash in energy levels later on, and may also contribute to headaches, nausea, and jitters.
Drinking an energy drink on an empty stomach can also irritate the stomach lining, leading to heartburn or indigestion.
It is best to consume energy drinks with a meal or snack to help slow down the absorption of caffeine and sugar, and to prevent any potential side effects.
If you do choose to drink an energy drink on an empty stomach, be sure to drink plenty of water to stay hydrated.