How many energy drinks a day is safe? Caffeine limits by can

How many energy drinks a day is safe? For most healthy adults, the FDA and EFSA put total caffeine at up to 400 mg a day. That is two and a half 500 ml Monsters at 160 mg each, or five 250 ml Red Bulls. Teenagers and pregnant people need far less, and coffee and cola count too.

Key points

• The 400 mg a day figure is for healthy adults and covers all caffeine, not only energy drinks.
• EFSA also says a single dose of up to 200 mg is not a concern for healthy adults. One big can can get close to that.
• For pregnancy and breastfeeding, the NHS and EFSA say no more than 200 mg a day.
• For children and teenagers, EFSA suggests no more than 3 mg per kg of body weight a day, and the FDA notes that medical experts advise against energy drinks for them at all.
• England plans to ban the sale of high caffeine energy drinks to under 16s from April 2027, subject to Parliament.

How much caffeine is in a can of Red Bull or Monster?

It depends on the can, and it varies a lot. The FDA's own range for energy drinks is 54 to 328 mg per 16 ounces. So the brand, the size and the country all matter, and the label is the only number to trust.

Here is the 400 mg adult limit in cans, using the makers' published figures where I could open them. The "cans to 400 mg" column is my arithmetic.

Drink and size	Caffeine per can	Cans to reach 400 mg
Red Bull Energy Drink, 250 ml	80 mg	5
Red Bull Sugarfree, 355 ml	114 mg	about 3.5
Red Bull Sugarfree, 473 ml	151 mg	about 2.6
Monster Energy, 500 ml or 16 oz	160 mg	2.5
Diet Coke, 12 oz	46 mg	about 8.7
Coca-Cola or Coke Zero Sugar, 12 oz	34 mg	about 11.8
Brewed coffee, 12 oz, FDA range	113 to 247 mg	about 1.6 to 3.5 cups

The Monster figure is the one I am least sure of. Monster's own site blocked me, so it comes from Caffeine Informer and an Open Food Facts label record, which both say 160 mg. Check your can.

One thing the table hides: most people do not drink only energy drinks. A Monster at 8 am, two coffees and a Coke at lunch can pass 400 mg without you noticing. Count everything.

How many energy drinks can a teenager have?

Ideally none. The FDA notes that medical experts, citing the American Academy of Pediatrics, advise against energy drinks for children and teens because of their sugar and caffeine. EFSA's suggested limit for children and teenagers is 3 mg of caffeine per kg of body weight a day.

For a 50 kg teenager, 3 mg per kg comes to 150 mg a day, by my arithmetic. That is less than one 500 ml Monster. A single can of a big energy drink can take a teenager past the limit in one go.

What is the UK under 16 energy drink ban?

On 16 July 2026 the UK government confirmed it will ban sales of high caffeine energy drinks to under 16s in England. It is due to start in April 2027, subject to Parliamentary approval. It covers drinks other than tea or coffee with more than 150 mg of caffeine per litre, in shops, vending machines and online, with fines of up to £2,500.

The government estimates about 100,000 children in England drink these drinks every day. Most colas fall under the line: a Diet Coke at 46 mg per 355 ml works out at about 130 mg per litre, by my arithmetic. A Red Bull at 80 mg per 250 ml is 320 mg per litre, more than double it.

My view, for what it is worth: the line is sensible, and it is about time. The law is for England only, and it is not in force yet, so do not treat it as a rule where you live.

How much caffeine is safe in pregnancy?

No more than 200 mg a day, according to both the NHS and EFSA. The NHS puts a 250 ml can of energy drink at about 80 mg, a can of cola at about 40 mg, a cup of instant coffee at about 100 mg and a cup of tea at about 75 mg.

So two small energy drinks and a cup of tea is already over the limit. The FDA's advice is to talk to your health care provider if you are pregnant, trying to get pregnant or breastfeeding. I would do that before changing anything.

When is it too much? The signs to take seriously

I am not going to give you a number of cans that causes a heart attack. No honest source gives one, because it depends on your body, your health and what else you take. What I can say is this.

See a doctor or get urgent help if you have chest pain, a racing or irregular heartbeat, fainting, or shortness of breath after energy drinks. Do not wait it out.

Less urgent signs that you are drinking more than suits you: poor sleep, feeling shaky or anxious, needing a can just to feel normal, and headaches when you skip one. That last one is caffeine withdrawal, and my caffeine withdrawal timeline covers what to expect.

How do I cut down on energy drinks?

Slowly, if you drink a lot. The FDA says that if you want to cut back on daily caffeine, you should do it gradually. Drop one can a week, or swap a big can for a small one, and keep a cold drink ready for the time of day you usually reach for one.

I built FizzFree for soda and energy drinks. It counts both in one app and shows the money you keep and the caffeine and sugar you skip. The Taper Dial lowers your weekly allowance step by step, and Ride the Fizz is a 90 second craving exercise: hold a finger down, breathe slowly, then decide. On iPhone, version 2.0 follows after App Store review. I compared it with the energy drink apps on the App Store in this post on apps to quit energy drinks.

Frequently asked questions

Is 2 energy drinks a day too much?

For most healthy adults, two 250 ml Red Bulls are 160 mg of caffeine, well under the 400 mg daily figure the FDA and EFSA use. Two 500 ml Monsters are 320 mg, closer to the line once coffee or cola is added. For teens and pregnant people, two is too many.

Is one Monster a day bad for you?

One 500 ml Monster has about 160 mg of caffeine, under the 400 mg adult figure, and about 54 g of sugar in the US 16 ounce can, per Caffeine Informer. The sugar is more than most daily limits. Zero sugar versions avoid that, but the caffeine is the same.

How much caffeine is in a Red Bull?

Red Bull says a 250 ml can of Red Bull Energy Drink has 80 mg of caffeine and 27 g of sugar. Its Sugarfree page lists 114 mg in a 355 ml can and 151 mg in a 473 ml can. Check your can, because recipes vary by country.

When does the UK energy drink ban start?

The UK government says April 2027, subject to Parliamentary approval. It will ban selling drinks with more than 150 mg of caffeine per litre, other than tea and coffee, to under 16s in England. It was announced on 16 July 2026 and was not law when I checked.

Can energy drinks cause heart problems?

Too much caffeine can cause a racing heart and palpitations, and some people are more sensitive than others. If you get chest pain, a racing or irregular heartbeat or fainting after energy drinks, get medical help. A doctor can tell you what is safe for you.

How I wrote this

On 24 October 2026 I read the FDA's caffeine page, EFSA's caffeine page, Red Bull's nutrition and caffeine pages, Coca-Cola's caffeine figures, the NHS page on caffeine in pregnancy and the UK government's 16 July 2026 announcement. Monster's site blocked me, so its caffeine figure comes from Caffeine Informer and Open Food Facts, and I say so. The cans to 400 mg and the per litre figures are my arithmetic. I did not give heart attack thresholds, because there are no reliable ones.

This is general information, not medical or veterinary advice. If you have a heart condition, are pregnant or take medicine, ask your doctor how much caffeine is safe for you.

By John Osakwe, founder of Etest Tech Hub. I have built apps and websites since 2015, including Etest CBT, FizzFree and Pawlarm.