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How Much Caffeine is Too Much Caffeine?

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Personally, there’s a very narrow line I must walk when it comes to caffeine. The right amount of coffee makes me feel like I can slay the day and just a little too much and I’m sweating through my shirt, feeling spacey and unfocused, and suffering from a rosacea flare!  Can you relate to the love-hate relationship? If so, let’s talk about how much caffeine is too much caffeine.

Where is caffeine found?

Caffeine has been identified in more than 60 plant species and history suggests that it may have been consumed as far back as the Paleolithic period (1)!

Currently, the most common dietary source of caffeine is coffee, but cocoa beverages, soft drinks, energy drinks, and specialized sports foods and supplements also contribute to regular intake (2).

Caffeine is also present in many prescription and nonprescription (i.e., over-the-counter) medications, including some taken for headache, pain relief, cold, appetite control, staying awake, asthma, and fluid retention (3).

What effects does caffeine have on the body?

After ingestion, caffeine is quickly absorbed from the gastrointestinal tract into the bloodstream. Once it’s in the bloodstream, caffeine promptly gets absorbed into body tissues and crosses over multiple barriers in the body, including the blood-brain barrier (a roadblock between your bloodstream and your brain which is there to protect your brain from toxins), the blood-placenta barrier for pregnant ladies, and the blood-testis barrier for men. Caffeine peaks in the blood anywhere from 15 minutes to 2 hours (4).

Caffeine is considered a drug because of its stimulant effects on the nervous system. It has been found to positively influence mental performance, increase energy, and improve mood (5).

Caffeine has been found to have a role in the prevention of physical degeneration from Parkinson’s disease (6) and studies have also shown that chronic caffeine consumption has been linked to a significantly lower risk of developing neurodegenerative diseases (meaning diseases that affect the brain and nervous system), such as Alzheimer’s disease.

Other benefits of caffeine consumption include improved mental alertness, speed reasoning, and memory, weight loss, improved physical performance during endurance exercise, and protection against certain skin cancers (7).

Negative side effects associated with caffeine include nervousness, anxiety, sleeplessness, irritability, dehydration, stomach upset, diarrhea, and nausea, increased heart rate, and both psychological and physical dependence (8).

What are the tolerable limits?

In adult men and non-pregnant women, the U.S. Food and Drug Administration considers 400 milligrams (about 4 cups of brewed coffee) a safe amount of caffeine for healthy adults to consume daily.

Pregnant women should limit their caffeine intake to 200 mg a day (about 2 cups of brewed coffee), according to the American College of Obstetricians and Gynecologists.

The American Academy of Pediatrics suggests that children under age 12 should not consume any food or beverages with caffeine. For adolescents 12 and older, caffeine intake should be limited to no more than 100 mg daily.  It may be worth noting, however, that many cultures around the world do introduce teas that may contain caffeine to children as young as two years old.

For comparison: 

  • 8oz of coffee contains 100mg of caffeine
  • 8oz of green tea contains 35 mg of caffeine
  • a can of soda contains anywhere from 40-72 mg of caffeine
  • energy drinks can range from 20-400mg+ of caffeine (yes, per drink!)
  • and caffeine content of drugs varies from 16 mg to 200 mg per tablet

How to decide how much caffeine is right for you

People have different tolerances and responses to caffeine, partly due to genetic differences. Take inventory of how you feel when you drink something caffeinated, and decide for yourself what makes sense.

If you feel jittery, anxious, or addicted to the rush, then perhaps you should pull back on the caffeine and opt for a chemical-free Swiss Water® Process decaf coffee or naturally uncaffeinated herbal tea. If you’re ultimately feeling better with less, then follow your body’s cues.

Keep in mind that not all caffeinated products are created equal! Opting for organic,  whole-food sources of caffeine, like coffee, tea, or cacao is going to provide other additional nutrients that will benefit your body. In general, it’s smart to avoid sodas, energy drinks, and other highly processed items with artificial sources of caffeine— as they are unnatural and can cause inflammation and other negative side effects.

Stay healthy,


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  1. Barone, J. J., & Roberts, H. R. (1996). Caffeine consumption. Food and Chemical Toxicology, 34(1), 119–129. doi:10.1016/0278-6915(95)00093-3

2-3, 5-6. Cappelletti, S., Daria, P., Sani, G., & Aromatario, M. (2015). Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug? Current Neuropharmacology, 13(1), 71–88. doi:10.2174/1570159×1366614121

  1. “Caffeine.” The Nutrition Source, 12 Nov. 2020,

7-8. “Caffeine: Benefits, Risks, and Effects.” Medical News Today, MediLexicon International,

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