How Long Does It Take for Caffeine to Wear Off?

This post may contain affiliate links. Please read my disclosure for more info.

We drink coffee for the flavor, but we also drink it for that boost of energy. That’s great during the workday, but you don’t want your morning habit to keep you up at night. So how long does it take coffee to wear off?

It takes about an hour for your caffeine levels to peak after you drink your coffee. Six hours after the drink, your caffeine levels will have decreased by half. In roughly ten hours, the effects will have diminished unless you are consuming large quantities of caffeine.

In this article, we’ll take a look at how caffeine affects you, how long it takes for those effects to wear off, and all the sources of caffeine in your diet that could be adding to the effect of your morning cup of coffee.

What Foods and Drinks Contain Caffeine?

We all know that coffee has caffeine, but there are several other sources of caffeine in our diets. It’s found in most soft drinks, energy drinks, and even chocolate.

The more caffeine you consume, the longer it will take to wear off, so make sure you’re aware of every way you are consuming caffeine.

  • Coffee — 95 mg per cup
  • Energy drinks — 85 mg per cup
  • Instant coffee — 60 mg per cup
  • Espresso — 64 mg per shot
  • Black tea — 47 mg per cup
  • Green tea — 28 mg per cup
  • Cola — 22 mg per cup
  • Diet cola — 30 mg per cup
  • Dark chocolate — 24 mg per ounce
  • Decaf coffee — less than 4 mg per cup

How Does Caffeine Affect the Body?

Positive effects of caffeine

Negative effects of caffeine

  • The coffee jitters — an anxious, nervous, shaky feeling
  • Headaches and dizziness
  • Insomnia
  • Dehydration
  • Diarrhea
  • Nausea
  • Increased blood pressure
  • Rapid heart rate and abnormal heartbeat

How Much Caffeine Is Too Much?

The FDA recommends no more than 400 mg of caffeine per day for the average adult. That’s roughly four standard cups of coffee, although some high-caffeine coffees have that much in a single cup.

Some people are more sensitive to caffeine than others. For the very caffeine sensitive, even a single cup can give them severe jitters, and the only healthy option is to stop entirely or switch to decaf.

If you’re pregnant or breastfeeding, you should stop at 200 mg of caffeine per day. About 1% of the caffeine that you consume makes its way into your breastmilk, peaking at one hour after you drink your coffee. Newborn babies have a hard time digesting caffeine, and it can last 10–20 times longer in their systems than it does in an adult.

How Long Does It Take for Caffeine to Kick In?

Caffeine can kick in as quickly as 15 minutes after you consume it. If you’re drinking your coffee quickly, that means you could get a pretty heavy dose before the first cup even has a chance to affect you.

It takes about an hour for the caffeine levels to peak in your body. That’s usually the time when you’ll start to feel jittery and energetic. It’s also the time when caffeine’s diuretic effects kick in, which is why you often need to pee soon after drinking coffee.

How Long Does Caffeine Stay In Your System

After the first hour, the effects of caffeine will start to diminish, but it can take a very long time, depending on how much caffeine you’ve consumed.

It takes about five hours for half the caffeine in your body to dissipate. This is known as the half-life of caffeine.

Let’s say you consumed 400 mg of coffee. Five hours after the peak, you’ll have about 200 mg left in your body. After five more hours pass, you’ll still have 100 mg of caffeine in your body.

So if you drink four cups of coffee at 8 AM, you may have a hard time getting to bed at 10 PM. After all, you’ll still have nearly a full cup of coffee worth of caffeine flowing through your veins!

Studies looking at the effect of caffeine on sleep found that most people need to avoid caffeine for six hours prior to their bedtime. So if you enjoy an after-dinner coffee, it should probably be decaf.

The Symptoms of Caffeine Withdrawal

If you decide to cut back on your caffeine intake, it’s best to do it slowly. The more you’ve been drinking, the more likely you are to have developed a dependence on caffeine.

Caffeine dependence can lead to several withdrawal symptoms if you cut back too quickly or quit cold turkey. These symptoms include:

  • Tiredness
  • Headaches
  • Nausea
  • Irritability
  • Muscle Pain
  • Difficulty concentrating

You can expect the withdrawal symptoms to start roughly 12–24 hours after your last caffeine intake. That is based on how long it takes for your body to digest its remaining caffeine, so it will be longer if you had more caffeine in your bloodstream already.

Withdrawal symptoms usually last between two and nine days. Their severity and length will depend on the level of your dependence. The more coffee you’re used to drinking, the worse your withdrawal will be.

Caffeinate Safely

Everyone responds differently to caffeine, but most people should expect the effects of caffeine to last for several hours.

Keep that in mind the next time you’re choosing between your favorite coffee k-cups and those extra strong coffee k-cups. The strongest coffees at Starbucks might taste good, but it’s probably best to avoid them in the afternoon and especially in the evening.