How Much Caffeine Is Too Much? Daily Limits, Warning Signs and d9-Caffeine

Caffeine is the most widely used stimulant in the world, and most people never think about the dose until something feels off: a racing heart, shaky hands or a night of staring at the ceiling. Here is how much caffeine is considered safe, the warning signs of too much, how much is in common drinks, and how d9-caffeine fits into your daily total.

The daily limits

The FDA cites 400 mg a day as an amount not generally associated with negative effects in healthy adults, roughly two to three 12-ounce cups of coffee. The European Food Safety Authority reached a similar conclusion, and added two useful details: single doses of up to 200 mg are not a concern for healthy adults, and intakes should stay under 200 mg a day during pregnancy and breastfeeding. EFSA also noted that about 100 mg close to bedtime can affect sleep in some people.

These are general reference points, not targets. People vary widely in how fast they clear caffeine and how strongly they feel it. Our guide to fast and slow caffeine metabolizers explains why.

Signs you have had too much caffeine

The FDA lists these signs that caffeine intake is too high for you:

• A fast heart rate or heart palpitations
• Higher blood pressure
• Trouble sleeping
• Anxiety or jitters
• Upset stomach or nausea
• Headache

More serious toxic effects, including seizures, can occur with rapid consumption of around 1,200 mg of caffeine. The FDA warns that pure powdered caffeine is especially dangerous: less than half a teaspoon can reach that amount, and a single teaspoon holds roughly as much caffeine as 28 cups of coffee.

How much caffeine is in common drinks

Coffee shop sizes are often 16 to 20 ounces, which can put a single drink well above 200 mg.

How d9-caffeine fits into your daily total

d9-caffeine is caffeine with nine hydrogen atoms replaced by deuterium, which slows how fast the liver breaks it down. In a 2022 double-blind study in 20 healthy adults, it was absorbed as quickly as regular caffeine and produced four to five times the total exposure of the same molar dose. That is why it is dosed in tens of milligrams, not hundreds, and why you should not convert between the two. Its developer cites up to 90 mg of d9-caffeine a day from all sources. Our explainer on what d9-caffeine is covers the research.

• Pick one main caffeine source. Do not stack Caffeine 2.0 on top of coffee and energy drinks.
• Keep it to the morning. d9-caffeine lasts longer than regular caffeine.
• Start with one capsule and add more only if you need it.

Who should check with a physician first

Seek urgent care for chest pain, fainting, a very fast or irregular heartbeat, confusion or seizures after caffeine. Skip caffeine products, or talk to your physician first, if you are pregnant or breastfeeding, under 18, sensitive to caffeine, or have a heart condition, high blood pressure, an arrhythmia, an anxiety disorder or a sleep disorder, and check with your physician or pharmacist if you take prescription medication.

How Vita Bloom fits

Caffeine 2.0 delivers a measured 22.5 mg of patented Deura9® d9-caffeine per capsule, with nothing else active, so you always know your dose. Start with one capsule in the morning, take up to four a day, and never exceed 90 mg of d9-caffeine.

Frequently asked questions

How much caffeine is safe per day?

For healthy adults, the FDA cites 400 mg a day as an amount not generally linked to negative effects. EFSA advises under 200 mg a day during pregnancy and breastfeeding.

What are the signs of too much caffeine?

A fast or pounding heartbeat, jitters, anxiety, trouble sleeping, upset stomach, nausea and headache.

How much caffeine is an overdose?

The FDA notes that toxic effects such as seizures can occur with rapid consumption of around 1,200 mg. Never use pure powdered caffeine.

How many Caffeine 2.0 capsules can I take?

Start with one in the morning. The maximum is four a day, or 90 mg of d9-caffeine, and you should not stack it with other caffeine.

Deura9® is a registered trademark of Lennham Pharmaceuticals, Inc. under exclusive license to d9 Designs Inc.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.