For many people, a morning without caffeine means a sluggish start to the day. Caffeine is a nervous system stimulant that clears drowsiness and gives you an energy boost.

Caffeine is such an effective stimulant that many people are using a highly concentrated caffeine powder, or caffeine anhydrous, to stimulate athletic performance or weight loss. According to the U.S. Food and Drug Administration (FDA), a teaspoon of caffeine powder is the equivalent of 28 cups of coffee.

This brings up questions about caffeine’s effects on your health. Is all this caffeine beneficial? How much caffeine is too much of a good thing?

Caffeine is a natural substance found in the seeds and leaves of certain plants. The caffeine in coffee comes primarily from Coffea arabica, a shrub or tree that grows in high-altitude subtropical and equatorial regions of the world.

Caffeine anhydrous is made from the seeds and leaves of coffee plants. The word “anhydrous” means “without water.” After harvesting, caffeine is extracted from the plant matter and dehydrated. This produces a highly concentrated caffeine powder.

When you ingest caffeine, it hitches a ride to your brain via your bloodstream. There, it mimics adenosine, a compound that’s present throughout your body.

Adenosine works like a depressant, slowing you down and making you sleepy. Caffeine mimics adenosine so effectively that it’s able to take the place of adenosine in your brain and liven things up.

The stimulant properties of caffeine are increased further because it enhances the effects of natural stimulants, including:

  • dopamine
  • norepinephrine
  • glutamate
  • adrenaline

After enjoying a caffeinated beverage, the full caffeine jolt usually occurs within an hour. The effects of the caffeine will wear off in three to four hours.

The FDA advises people to avoid highly concentrated caffeine, citing the deaths of at least two young men who used the products. Spurred by the growing incidence of caffeine intoxication due to use of caffeine anhydrous, the FDA issued warning letters to five manufacturers of powdered caffeine in September 2015.

The letters state that caffeine powder “presents a significant or unreasonable risk of illness or injury.” The FDA further stated that the recommended doses on the caffeine powder labels are impossible to portion out accurately using common household measuring tools.

Although taking powdered caffeine doesn’t appear to be worth the risk, there’s good news for coffee drinkers. According to the FDA, a healthy adult can safely drink 400 mg of caffeine per day, equal to four or five cups of coffee.

An overdose of caffeine can be fatal. Symptoms of caffeine intoxication can include:

  • racing or erratic heartbeat
  • vomiting
  • diarrhea
  • seizures
  • abdominal pain
  • muscle tremors or twitching
  • agitation
  • confusion

If you have these symptoms, seek immediate medical care.

Caffeine does have beneficial properties:

  • It reduces fatigue and improves concentration.
  • It improves athletic performance, particularly when engaging in endurance sports.
  • It’s effective in relieving tension headaches, especially in combination with ibuprofen (Advil).
  • It contains antioxidants that prevent or slow cell damage and may offer protection from heart disease and diabetes.
  • Coffee drinkers have fewer gallstones.
  • It offers men some protection against Parkinson’s disease.

Caffeine does have some downsides:

  • It’s been associated with an increased risk of sudden cardiac death because it can cause an erratic heartbeat.
  • Caffeine is a diuretic, meaning it causes you to urinate more frequently. This can lead to dehydration, especially if you’re not drinking enough water or if you’re exercising vigorously.
  • Over time, caffeine causes your body to lose calcium, which can lead to loss of bone density and osteoporosis.
  • It increases anxiety, nervousness, and insomnia.
  • Chemicals in coffee increase cholesterol levels. (Using a paper filter when making coffee will reduce this risk significantly.)

The following groups of people should avoid caffeine:

Pregnant women

If you’re pregnant, you should limit your caffeine intake to 200 mg a day, according to the American College of Obstetricians and Gynecologists.

Women who are breastfeeding

Research about the effects of caffeine on the infants of nursing mothers isn’t conclusive. The American Academy of Pediatrics (AAP) advises breastfeeding mothers to drink caffeinated beverages in moderation. The organization recommends that nursing mothers drink no more than three cups of coffee or five caffeinated beverages a day.

Only about 1 percent of the caffeine you consume is found in your breast milk, according to AAP. However, infants don’t metabolize caffeine well, and it can stay in their bloodstream longer. The result may be a restless, irritable baby.


The FDA hasn’t issued guidelines for caffeine consumption by children. Canadian guidelines recommend no more than one 12-ounce caffeinated beverage per day for children between the ages of 4 and 6.

In a study published in the journal Pediatrics, AAP recommends that children and adolescents not consume more than 100 mg of caffeine per day. To get an idea of what this means, a 12-ounce cola contains between 23 mg and 37 mg of caffeine.

People on certain medications

Check with your doctor or pharmacist about possible interactions with medications you take, such as:

  • quinolone antibiotics, used to treat infection
  • the bronchodilator theophylline (Uniphyl), which makes it easier to breathe
  • heart regulation drugs, such as propranolol
  • certain varieties of birth control pills
  • echinacea, an herbal supplement

People with some mental disorders

Caffeine may make your symptoms worse if you have generalized anxiety disorder or panic disorder.

People who have certain conditions

Talk with your doctor about caffeine consumption if you have:

  • heart disease
  • liver disease
  • diabetes

If you’re a java junky looking to cut back on caffeine, withdrawal symptoms may begin within a day of your last cup of joe. Usual signs of withdrawal include:

  • headache
  • sleepiness
  • irritability

Decreasing your caffeine intake slowly will help reduce these symptoms.