Why Does Caffeine Make Me Tired?

Cup of Coffee

For many of us, caffeine is our go-to drug of choice. First thing in the morning, or when your energy slumps midday, reaching for a cup of coffee is the clear answer. But, have you ever thrown back an espresso shot or polished off your Joe only to feel more tired? It’s possible your genes could be to blame.

“There are clear genetic variations on how certain individuals metabolize caffeine [fast metabolizers vs. slow metabolizers],” says Kristin Kirkpatrick, R.D., Cleveland Clinic Manager of Wellness Nutrition Services. To find out where you stand, you can have a nutragenomix test performed. “The test looks at how quickly or slowly someone breaks down caffeine based on variants of a certain gene (called the CYP1A2 gene) to determine if caffeine is beneficial or harmful to your health,” says Kirkpatrick.

But before you go running to your doc for a test, consider the other possibilities. For one, it’s possible to form a mild tolerance to caffeine. So, cutting back on it and then reintroducing it could help. What’s more, “Caffeine is a stimulant, so theoretically, consuming it should increase blood pressure, heart rate, alertness, and energy; but the effects may be temporary, and once the caffeine has worn off, your fatigue may feel worse,” says Kirkpatrick. Kinda like that sugar high you get immediately after polishing off a piece of cake or a few donuts. The high comes with a crash.

Caffeine is also a diuretic, so having a lot of it means that you’re more likely to become dehydrated. “By the time the caffeine wears off, your hydration levels may be in the tank and the double whammy of caffeine withdrawl and dehydration can take a serious sleepy toll,” says Kirkpatrick. (We’re talking a lot, a lot though. If you’re just drinking a normal amount, the water in coffee seems to offset the dehydrating effects of caffeine.)

Also consider the fact that no amount of coffee or caffeine is going to make up for tons of lost sleep or the energy-sapping effects of living an unhealthy lifestyle. Try these 50 ways to instantly amp your energy. And if you’re always low on energy, skip the Joe and head to your doctor, says Kirkpatrick.

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