For healthy adults, up to four to five 250ml cans of Red Bull per day (around 400mg caffeine) is generally considered safe, according to European Food Safety Authority (EFSA), but it's best to moderate intake, ideally sticking to no more than one or two as an occasional boost to avoid jitters, anxiety, or sleep issues, especially if you have heart conditions. Pregnant women, people with high blood pressure, or heart problems should limit caffeine much more, ideally to 200mg/day or less.
Red Bull offers several 'healthier' choices, but they come with risks, such as artificial sweeteners. Overall, you're generally better off limiting yourself to no more than 1-2 cans each day. Unless you have a pre-existing health issue, this is unlikely to cause you any problems in the near future.
The bottom line. If you have heart problems or high blood pressure, avoid energy drinks. If you are healthy and need a quick surge of energy, it is okay to consume an occasional energy drink — no more than one a day — but this shouldn't be a daily or long-term practice.
There's no single "worst" energy drink, but those high in sugar and caffeine like Monster, Rockstar, and Red Bull are often cited due to risks of crashes, weight gain, and potential severe side effects (like seizures or heart issues in extreme cases) from excessive consumption, especially when mixed with alcohol. Drinks like 5-Hour Energy are also flagged for their concentrated stimulant load, despite being sugar-free, and even "healthier" ones still pack high caffeine.
The 15 Healthiest Energy Drinks
The analysis shows a significant prevalence of adverse effects, particularly on the cardiovascular and neurovegetative systems.
Your blood sugar levels will spike shortly after drinking a high-sugar energy drink, but the boost in energy will only last 30 to 60 minutes. After this, your blood sugar — and energy levels — will crash, leaving you feeling more tired than before. Symptoms of a sugar crash include: Tiredness.
The European Food Safety Authority (EFSA) concluded in its 2015 scientific opinion on the safety of caffeine that an intake of up to 400 mg per day (equivalent to five 8.4 fl oz cans of Red Bull or five cups of coffee a day) does not raise safety concerns for healthy adults.
What are caffeine overdose symptoms?
Excessive coffee consumption can lead to unwanted effects such as restlessness, tremors or tachycardia – however, caffeine poisoning is not to be expected in healthy adults with normal coffee consumption. The potentially fatal dose of caffeine for an adult is considered to be around 5 to 10 g.
Too much caffeine in children and teens can cause increased heart rate, heart palpitations, high blood pressure, anxiety, and lead to sleep problems, digestive problems and dehydration.
Caffeine sensitivity cannot be changed, but caffeine tolerance can. Caffeine tolerance is built up over time and can happen as fast as one week. Caffeine creates stimulation by blocking adenosine receptors in our brains. When we regularly consume caffeine, our brain adapts, and develops more adenosine receptors.
There's no single "worst" energy drink, but those high in sugar and caffeine like Monster, Rockstar, and Red Bull are often cited due to risks of crashes, weight gain, and potential severe side effects (like seizures or heart issues in extreme cases) from excessive consumption, especially when mixed with alcohol. Drinks like 5-Hour Energy are also flagged for their concentrated stimulant load, despite being sugar-free, and even "healthier" ones still pack high caffeine.
The recommended daily limit for caffeine is 400 milligrams per day, which is equivalent to about 4 cups of coffee. Many energy drinks meet this amount and you might exceed it if you have more than one drink each day.
That's why it's recommended that you consume any energy drinks between 9-11:30 a.m. (or a couple hours after waking) when your cortisol levels have lowered, and you can get the energy-boosting effect from your drink rather than the stress-inducing one.
Still, Levine believes “it's potentially dangerous stress on the heart for anyone with heart disease to drink these concoctions of caffeine and sugar and a perfect storm to induce palpitations.” He notes that's especially true for anyone trying to get a little pick-me-up.
Three early warning signs of heart failure include persistent fatigue/weakness, shortness of breath (especially with activity or lying down), and swelling (edema) in your legs, ankles, and feet, often accompanied by rapid weight gain from fluid buildup, all signaling your heart isn't pumping efficiently enough. Other key indicators are a chronic cough (sometimes with pink mucus) and heart palpitations.
Caffeine addiction: Energy drink addiction and caffeine addiction are closely linked since energy drinks primarily contain caffeine, which is a stimulant. Overconsumption of caffeine leads to dependence, with symptoms such as headaches, irritability, and fatigue when consumption is reduced or stopped.
Instead of a sugary energy drink, try drinking fresh juice, greens powder, green tea, matcha, or yerba mate, or even snacking on a few squares of dark chocolate to get you through your mid-day slump. You may also want to consider consuming kombucha, probiotic soda, kefir, or even low-sugar sports drinks.
Companies that align their strategies with these trends are well-positioned to capitalize on the growing demand for energy-boosting beverages.
Lack of energy is even more concerning among the younger Generation Z and Millennial generations. That is why consumer trends research by Innova Market Insights shows that these younger Gen Z and Millennial consumers have solid and ongoing demand for energy drinks.
The primary treatment for minor caffeine ingestion is supportive care, including advanced cardiac life support or pediatric advanced life support as needed. Hydration may be oral for minor cases. Patients with severe toxicity benefit from intravenous hydration.