Still, feeling like your heart is thumping to a dubstep beat isn’t pleasant.
Which brings us to the bad news: you’re going to be feeling like this for a while.
“Four-to-six hours is the general rule of thumb for how long it takes caffeine to wear off,” says Heller.
However, there’s a range in how people metabolise the stimulant. Your weight, genetics and tolerance will determine how edgy you feel and for how long. Unfortunately, there’s not a ton you can do to speed up that process, says Heller.
Dr Adam Splaver, a cardiologist, suggests hydrating well to flush the caffeine out of your system. Exercise may also help, since it will torch excess energy while speeding up your metabolism.
If you start to feel yourself panicking, Heller recommends taking a deep breath and reminding yourself that the situation is chemically induced and temporary, since caffeine is a central nervous system stimulant.
“It affects the body chemistry in ways that make us launch into fight or flight mode,” she says, so freaking out only makes the situation worse.
To be sure of avoiding these feelings, you can always give up coffee. But if that's out of the question, limit your caffeine intake to 400 milligrams a day, says Heller. Most brewed coffee has anywhere from 80 to 200 milligrams.
“There’s a lot of variation depending on how it’s made and what type of coffee it is,” she explains.
Two or three cups in a sitting is generally fine; even four cups may be safe if you have a high caffeine tolerance. Going over that, though, is asking for trouble.
And if you start feeling nauseous, faint or dizzy, you may be teetering on the edge of a true overdose. While very rare, overdoses can be serious, especially if you have a known heart condition or high blood pressure.
“An overdose can cause heart-rhythm disturbances, vasoconstriction, heart attack, stroke and high blood pressure in certain populations,” says Splaver.
If you think you’ve truly overdosed, you should head to the emergency room – just don’t blame your barista for over-serving you.