You probably already knew that grapefruit–especially grapefruit juice–can interact with many medications, making them act stronger because it slows the rate at which your liver removes them from your body.
It turns out that grapefruit has the same effect on caffeine. That explains the occasional extra buzz at breakfast!
Caffeine normally has a half-life of about 5 hours, meaning that your body removes half of it in that amount of time. Grapefruit increases the half-life, so you might still be caffeinated at bed-time.
If you are sensitive to caffeine, use this knowledge to fine-tune your intake to avoid jitters and sleepless nights. Either drink less or drink it earlier, to give your body more time to remove it.
Have a good day!