Celsius vs Red Bull: Which has more caffeine, actually?

Many Celsius cans have more caffeine than a classic 8.4 oz Red Bull (often about 200 mg per 12 oz vs about 80 mg per 8.4 oz, depending on the product and country). Is Celsius like Red Bull? Yes, both are caffeinated energy drinks meant to boost alertness, but the typical Celsius can is a much bigger stimulant hit. Celsius is usually sugar-free and lower in calories, while classic Red Bull is lower in caffeine but far higher in sugar in the regular version, so Celsius can be healthier than regular Red Bull for waistline and blood-sugar goals yet worse for sleep, anxiety, and palpitations in some men. In a “celsius vs red bull zero sugar” matchup, sugar is not the decider, caffeine dose and timing usually are. Here’s how to choose the lower-risk option between these cans and when to skip both.

Key takeaways

• A standard 12 oz Celsius can often contains about 200 mg caffeine, while a classic 8.4 oz Red Bull has about 80 mg; formulations vary by product and country, so check the label.
• Regular Red Bull adds roughly 27 g sugar per can, which is strongly linked with weight gain, higher triglycerides, and higher type 2 diabetes risk; zero-sugar versions avoid the glucose load but still deliver stimulant effects.
• Energy-drink “stacks” (caffeine plus taurine and herbal extracts like guarana/green tea) can raise heart rate and blood pressure, and some studies have reported small, short-lived changes in ECG measures such as QTc after large servings; evidence is mixed and most effects appear small in healthy adults.
• Up to 400 mg/day of total caffeine is a common safety guideline for healthy adults, but stacking two high-caffeine energy drinks plus coffee or pre-workout can exceed it and increase palpitations, anxiety, and blood-pressure spikes.
• To protect sleep and recovery, avoid energy drinks within six hours of bedtime; poor sleep can lower testosterone, and possible hypogonadism should be evaluated with two morning tests that include Total Testosterone and Free Testosterone measured directly by Equilibrium Dialysis with LC-MS/MS. When symptoms persist, Veedma uses thresholds of Total Testosterone below 350 ng/dL and Free Testosterone below 100 pg/mL rather than relying only on the lab’s reference range.

The relationship

Celsius typically contains more caffeine per can than classic Red Bull. In terms of men’s health, whether Celsius is “worse” or “healthier” depends on which risk matters most for you: Celsius is usually better than regular Red Bull for metabolic health because it is typically sugar-free, but it can be worse for sleep, anxiety, and palpitations because it usually packs far more caffeine per can. Especially if you’re sensitive to stimulants or drink it late in the day.

If you’re typing “is celsius like red bull” into Google, the honest answer is yes in category and purpose, but no in the way most men experience it day to day. Both are carbonated energy drinks built around caffeine plus a mix of add-ons like taurine, B vitamins, and herbal extracts. The difference is that many Celsius varieties are closer to a double dose of stimulant compared with the classic small Red Bull can, and that changes the risk profile for sleep, anxiety, and palpitations.²

Men who search “red bull vs celsius” are usually trying to answer a more personal question: is Celsius or Red Bull worse for you. In general, regular Red Bull tends to be the “worse” everyday habit for waistline and triglycerides because it brings a meaningful sugar load, while Celsius tends to be the “worse” choice for sleep, anxiety, and palpitations because it usually delivers a much higher caffeine dose in one can.^{4 2}

Celsius typically contains more caffeine and less sugar than classic Red Bull. For many men, the decision still starts with a simple comparison of stimulant dose and sugar load. You are really weighing two different risk profiles, not two versions of the same thing. Both are canned stimulants, yet they are built very differently. A standard 12‑ounce Celsius can often lists about 200 milligrams of caffeine with no sugar, while a classic 8.4‑ounce Red Bull has about 80 milligrams of caffeine plus roughly 27 grams of sugar; formulations vary by product and country, so check the label. So, does Celsius have more caffeine than Red Bull? Yes, in many common can-to-can comparisons, and that higher dose is why a lot of men feel Celsius “hits harder.” When you compare the two, you’re mainly weighing stimulant dose, sugar load, timing (especially later in the day), and your personal risk factors like anxiety, high blood pressure, or sleep issues. The most accurate answer is this: Celsius is usually healthier than regular Red Bull for metabolic health because it avoids sugar, but it can be worse for sleep, anxiety, and palpitations because it delivers much more caffeine per can.

There is also a practical wrinkle that matters in real life. Red Bull comes in both sugar-sweetened and zero-sugar versions, and men often compare a full-can Celsius to a Red Bull zero sugar can. In that head-to-head, the sugar issue mostly disappears. Then the decision is about caffeine dose, ingredient “stacks,” and timing, not calories. In that scenario, it often comes down to which one you can use without wrecking your sleep or spiking your blood pressure.

If you want a quick “celsius energy drink vs coffee health comparison,” think of coffee as the simpler baseline. Coffee is mostly caffeine plus water and naturally occurring compounds, while energy drinks are a more engineered mix with sweeteners, acids, and added ingredients that can change how hard the drink feels in your body. Coffee can still drive insomnia and anxiety in some men, and serving size can quietly double your dose, so the same rules apply: count milligrams, watch timing, and respect your sleep.¹

Caffeine is a central nervous system stimulant. That means it speeds up brain and nerve activity, which most men feel as better alertness, reaction time, and mood. According to a widely cited 2003 safety review in Food Additives and Contaminants, up to 400 milligrams of caffeine per day is generally safe for healthy adults, and more recent public-health guidance (including FDA and EFSA summaries) is broadly consistent with that limit for most healthy adults, while emphasizing that some people should aim lower.¹ Individual tolerance varies, and men with anxiety, uncontrolled high blood pressure, a history of arrhythmia, or significant sleep problems may need a lower ceiling. That’s why there’s no one-size answer. If sugar is your main risk, Celsius often wins. If caffeine is your main trigger, Celsius can be worse than Red Bull.

Energy drinks add more than caffeine. Red Bull combines caffeine with sugar and taurine. Taurine is an amino-sulfonic compound (often called an amino acid) that helps regulate calcium flow and cell volume in heart and muscle cells, among other roles. Celsius includes caffeine (often sourced from green tea and guarana) plus added ingredients such as ginger and B vitamins. According to a 2010 Mayo Clinic Proceedings review, these multi-ingredient energy drinks can raise heart rate and blood pressure, and the effects may be more pronounced than caffeine alone in some people.² Some studies have also reported small changes in ECG measures such as QTc after large servings, though evidence is mixed and clinical significance is unclear in healthy adults. In a real-world Red Bull vs Celsius comparison, that “stack” matters because men do not just respond to caffeine. They respond to the whole can.

How it works

What has more caffeine, Red Bull or Celsius? Comparing caffeine dose

Caffeine dose is the first big difference when you look at Celsius caffeine vs Red Bull. A standard 12‑ounce Celsius can often contains about 200 milligrams of caffeine, while a regular 8.4‑ounce Red Bull has about 80 milligrams. Sugar‑free Red Bull still has about 80 milligrams. So if you’re trying to figure out what has more caffeine, Red Bull or Celsius, in the standard cans most men buy, the answer is usually Celsius. In practical terms, that means the caffeine in Red Bull vs Celsius is not close unless you choose a larger Red Bull size or drink multiple cans. When in doubt, check the exact can size and caffeine number on the label, because totals vary by product, serving size, and country.

If you’re comparing the two and you’re a guy who grabs whatever size is in the cooler, check the can. Red Bull’s larger sizes contain more caffeine than the 8.4‑ounce can, but one Celsius still typically lands closer to the caffeine in about 2.5 of the small Red Bulls. That matters because men often underestimate their real stimulant load across a day.

Men also compare energy drinks to coffee because both are used for focus, long drives, and pre-gym motivation. If you’re searching “celsius energy drink vs coffee health comparison,” remember that coffee dose can be surprisingly variable by brew method and cup size, while energy drinks list a fixed caffeine number per can. That can make coffee easier to scale down if you stop at one small cup, but easier to accidentally overdo if your “one coffee” is a large mug refill.¹

If you’re comparing the two and your specific question is “red bull caffeine content vs celsius,” the label math is straightforward. Classic Red Bull has about 80 milligrams of caffeine in 8.4 ounces. A standard 12‑ounce Celsius can often lists about 200 milligrams in 12 ounces. One Celsius is roughly the caffeine of 2.5 of the small Red Bulls most men grab at a gas station or airport kiosk.²

If your comparison is specifically “celsius vs red bull zero sugar,” this is the key point. Both are typically low calorie and avoid the glucose hit. What you are really choosing is how much stimulant you want in one sitting, and whether you can take that dose without anxiety, palpitations, or sleep disruption.

On a per‑ounce basis, Celsius is also more concentrated in many common versions. A 12‑ounce Celsius at 200 milligrams works out to about 16.7 milligrams per ounce, while an 8.4‑ounce Red Bull at 80 milligrams is about 9.5 milligrams per ounce. That difference helps explain why some men feel fine on one Red Bull but get jitters or palpitations on one Celsius, even if both are “just one can.”

According to a 2014 review in Sports Medicine by Spriet, performance studies often use caffeine doses around 3 to 6 milligrams per kilogram of body weight taken before exercise to improve alertness and exercise performance, while higher single doses increase the odds of side effects such as jitters, palpitations, and blood-pressure increases.³ For a 90‑kilogram man, that pre‑exercise range is roughly 270 to 540 milligrams, which is more than many men need and can approach (or exceed) a full day’s total. Many men should still keep total daily caffeine at or below about 400 milligrams, and lower if they are sensitive or have heart, anxiety, or sleep issues; two high-caffeine energy drinks plus a strong coffee can push a man past that guideline.¹

Sugar and calories: why Celsius can be better than Red Bull for men’s metabolism

Metabolism is how your body turns food and drink into energy. When men compare Celsius caffeine vs Red Bull, the sugar difference matters for weight, blood sugar, and long‑term heart risk. If your main goal is cutting belly fat, the key question is whether you are choosing a zero-sugar can or a sugar-sweetened one. For many men, this is the real health tradeoff, because waist size and triglycerides do not care about marketing.

Original Red Bull delivers around 27 grams of sugar in each small can, which is almost seven teaspoons. According to a 2010 review in Circulation by Malik and colleagues, regular intake of sugar‑sweetened beverages is linked with weight gain, higher triglycerides, and a higher risk of type 2 diabetes and cardiovascular disease.⁴ These changes drive metabolic syndrome, a cluster of problems that raises heart attack and stroke risk.

If you’re asking “why is celsius better than red bull,” this is usually the reason. Most Celsius products are sugar-free, so you can get caffeine without stacking liquid calories and a fast glucose hit on top of an already high-calorie day. That can be a real advantage for men trying to drop belly fat or rein in triglycerides, as long as the higher caffeine dose does not sabotage sleep and recovery.⁴

Here is the “Celsius vs Red Bull zero sugar” reality. If you compare Celsius to Red Bull zero sugar, both options avoid the sugar spike and extra calories. At that point, “healthier” usually means the drink that least disrupts your sleep, blood pressure, and anxiety. For a lot of men, that ends up being the smaller caffeine dose, not the flashier ingredient list.

Celsius and sugar‑free Red Bull avoid sugar by using non‑nutritive sweeteners. These are chemicals or plant extracts that taste sweet without calories. Some studies suggest certain artificial sweeteners can alter gut bacteria and glucose control, though the evidence is mixed and depends on dose and type of sweetener. For example, Suez and colleagues reported in Nature (2014) that several non‑nutritive sweeteners altered the gut microbiome and were associated with worse glucose tolerance in some participants, but findings do not apply equally to every sweetener or every person.⁶

Other stimulants and additives: why Celsius versus Red Bull can feel different

Beyond caffeine and sugar, both drinks bring extra stimulants. Red Bull contains taurine, glucuronolactone, and B vitamins, while Celsius adds green tea extract, guarana, ginger, and its own vitamin mix. Guarana is a plant source of caffeine. That means “natural” caffeine still loads the same receptors in your brain and heart as synthetic caffeine.

Some research suggests energy drinks combining caffeine with taurine and other ingredients can produce bigger cardiovascular changes than caffeine alone. A 2014 randomized cross-over study in the European Journal of Nutrition, Grasser and colleagues found that Red Bull increased blood pressure in young adults compared with control conditions.⁵ As noted in the 2010 Mayo Clinic Proceedings review, multi-ingredient energy drinks can also raise heart rate and blood pressure and have been tied to arrhythmia case reports, especially when men take in high doses or stack multiple stimulants in a day.² Some studies have also reported small changes in ECG measures such as QTc after large servings, though results are inconsistent and most changes appear modest in healthy adults. Most cans also pack high doses of niacin, a B vitamin that helps with energy metabolism. Niacin is generally safe at the amounts found in single cans, yet very high supplemental doses over time can damage the liver in some men.

This is one reason the two drinks can feel different even when both are sugar-free. Men who tolerate 1 small can of Red Bull zero sugar may still feel overstimulated with 1 can of Celsius, because the caffeine dose is higher and the blend includes additional extracts that can change the subjective “hit.”

Impact on gut and digestion

Digestive health matters when you decide between Celsius caffeine vs Red Bull. Caffeine stimulates stomach acid and speeds up intestinal movement. That can trigger heartburn, loose stools, or cramping in some men who are sensitive.

High sugar loads, like those in regular Red Bull, draw water into the intestines and can worsen bloating or diarrhea in men with irritable bowel tendencies. Sugar alcohols (for example, erythritol or sorbitol) can cause gas, bloating, and diarrhea in some people, especially at higher amounts. Celsius and Red Bull zero-sugar products generally rely on non‑nutritive sweeteners such as sucralose, acesulfame potassium, and sometimes aspartame; these don’t usually ferment like sugar alcohols, but some individuals still report GI symptoms. Some research, including the 2014 Nature paper by Suez and colleagues, suggests certain non‑nutritive sweeteners can shift gut microbiome balance, although the health impact in real‑world doses remains uncertain.⁶

Sleep, hormones, and performance recovery: when Celsius can be worse than Red Bull

Is Celsius worse than Red Bull for sleep? It can be, mainly because you are usually starting with a much higher caffeine dose in one can. Caffeine has a half‑life of about five to six hours in most adults. Half‑life means the time it takes for half the dose to clear from your blood. A 2013 study in the Journal of Clinical Sleep Medicine by Drake and colleagues found that 400 milligrams of caffeine taken zero, three, or six hours before bed still reduced total sleep time in healthy adults.⁸ Deep sleep supports recovery, and insufficient sleep can lower testosterone levels and impair next-day performance.

A 2011 JAMA study by Leproult and Van Cauter reported that even one week of sleeping less than five hours per night can lower daytime testosterone by 10 to 15 percent in young men.⁷ Possible hypogonadism should be evaluated with two morning tests that include Total Testosterone and Free Testosterone measured directly by Equilibrium Dialysis with LC-MS/MS, and when symptoms persist, Veedma uses thresholds of Total Testosterone below 350 ng/dL and Free Testosterone below 100 pg/mL rather than relying only on the lab’s reference range.⁹ If late‑day caffeine from high‑dose drinks like many Celsius varieties is clipping your sleep, it can push you toward fatigue, lower libido, and slower recovery long before you meet criteria for clinical hypogonadism.

Conditions linked to it

The way you use energy drinks matters more than the brand name on the can. Specific health conditions in men can get worse with heavy or poorly timed Celsius or Red Bull intake. The most important factor is usually your underlying risk, including blood pressure, anxiety, and sleep quality. In practical terms, both can become a problem when they push you into high total caffeine, poor sleep, or a daily sugar habit. If you are deciding which one is the lower-risk choice for you, start with what you are most vulnerable to. For many men that is either belly fat and triglycerides, or insomnia and palpitations.

• High blood pressure and heart disease. Randomized studies show that energy drinks can acutely raise blood pressure and heart rate in healthy people, and the 2010 Mayo Clinic Proceedings review by Higgins and colleagues discussed case reports linking heavy use to arrhythmias, including atrial fibrillation.² Men with known hypertension, structural heart disease, or a history of arrhythmia should be cautious with any high‑caffeine drink.
• Obesity, prediabetes, and type 2 diabetes. Frequent intake of sugary drinks like regular Red Bull is tied to larger waistlines, higher fasting glucose, and a higher risk of type 2 diabetes in men. The association is summarized in the 2010 Circulation review by Malik et al.⁴ Celsius avoids sugar, so it is less likely to spike blood sugar directly, yet large volumes can still feed cravings for sweet, ultra‑processed foods.
• Gastroesophageal reflux disease, or GERD. GERD is chronic acid reflux that irritates the throat and esophagus. Caffeine and carbonation can trigger reflux symptoms in some men, and sugary drinks may also worsen heartburn for some people, though triggers vary by individual.
• Anxiety and sleep disorders. High doses of caffeine, especially late in the day, worsen insomnia and anxiety in susceptible men. Those with generalized anxiety, panic disorder, or chronic insomnia often improve simply by trimming total caffeine and moving energy drinks to earlier in the day.
• Low testosterone and overtraining. Men who rely on a daily stack of Celsius, coffee, and pre‑workout to push through chronic fatigue may be compensating for sleep deprivation, under-fueling/low energy availability (sometimes called relative energy deficiency in sport, or RED-S, which is more common in athletes who chronically under-fuel), overreaching/overtraining, depression, or medical causes such as thyroid disease, anemia, or sleep apnea. Caffeine can help you get through today’s workout while making tonight’s sleep and tomorrow’s recovery worse.

Limitations note: Most clinical studies examine generic energy drinks, sugar‑sweetened beverages, or pure caffeine, not Celsius or Red Bull specifically. Effects in an individual man depend on genetics, total dose, other sources of caffeine, alcohol use, and pre‑existing health conditions.

Symptoms and signals

Watch for these red flags that your current Celsius caffeine vs Red Bull routine is not serving your health, even if it feels good in the moment.

• Racing, pounding, or skipped heartbeats after a single can.
• Shakiness, feeling “wired,” or anxious during meetings or workouts.
• Needing more cans over time to feel the same energy boost.
• Heartburn, sour taste in your mouth, or chest burning after drinking.
• Cramping, loose stools, or urgent bathroom trips after an energy drink.
• Trouble falling asleep if you have any caffeine after lunch.
• Waking unrefreshed, even when you spend seven to eight hours in bed.
• Steady weight gain around your waist if you drink sugar‑sweetened Red Bull most days.
• Drop in morning erections, libido, or strength that tracks with worsening sleep and higher caffeine use.

If symptoms hit, stop caffeine for the day, hydrate, and avoid stacking more stimulants (including pre‑workout, nicotine, and decongestants). Mild, short-lived stimulation, such as feeling more alert, a small increase in heart rate during a workout, or a little restlessness, can be expected. Concerning reactions are symptoms that are new for you, intense, keep worsening, or keep happening even at low doses.

Seek urgent care now (or call emergency services) for chest pain or pressure, shortness of breath, fainting, confusion, severe headache, weakness on one side, or sustained palpitations with dizziness. If you have recurrent palpitations, repeated blood-pressure spikes, panic symptoms, or insomnia that persists after cutting back, schedule a routine evaluation with your clinician to review caffeine intake, medications and supplements, blood pressure, and possible heart rhythm testing.

What to do about it

You do not need to swear off caffeine for life. The goal is to make smart, man‑specific choices about Celsius caffeine vs Red Bull and your overall stimulant load. If you are deciding between the two, make the decision based on your biggest vulnerability: sugar and waistline, or caffeine and sleep. That is usually the cleanest way to figure out the lower-risk option for your body.

If you’re deciding between Celsius or Red Bull and you want a quick rule, start here. If you drink regular Red Bull most days, switching to a zero-sugar option is usually a net win for weight and metabolic risk. If you’re comparing two zero-sugar options, the healthier choice is often the one that lets you sleep well and keeps your total caffeine under control. And if you’re wondering “is Red Bull healthier than Celsius,” the answer is usually “not the sugary version,” but the lower caffeine dose in Red Bull can be easier on some men’s sleep and anxiety.

If you’re choosing between an energy drink and coffee, keep it simple. In a “celsius energy drink vs coffee health comparison,” plain black coffee or unsweetened tea earlier in the day often gives you caffeine with fewer added ingredients than an energy drink, and you can usually control the dose more easily. If you do choose an energy drink, pick the smallest effective can and avoid combining it with coffee or pre‑workout in the same morning, which is how many men accidentally blow past their personal tolerance even when they stay under a “safe” ceiling.¹

If your main question is “is celsius or redbull worse for you,” try answering this instead. Which one makes you more likely to sleep poorly tonight, or to drink extra calories you did not plan for today. For many men, regular Red Bull is more likely to nudge weight and blood sugar in the wrong direction over time, while Celsius is more likely to trigger jitters, a racing heart, or a delayed bedtime when it is used too late.

1. Audit your intake and your health. For one week, write down every source of caffeine you use. Include Celsius, Red Bull, coffee, tea, pre‑workout, and sodas. Add up your typical daily total in milligrams. Aim to stay at or under 400 milligrams per day if you are a healthy adult man, and less if you have heart or sleep issues.¹ At the same time, check your blood pressure at home and review recent labs such as fasting glucose, triglycerides, and liver enzymes with your doctor. If you have fatigue, low libido, or erectile changes along with poor sleep, get a fuller male hormone evaluation with two morning draws that include Total Testosterone, Free Testosterone measured directly by Equilibrium Dialysis with LC-MS/MS, LH, and FSH.⁹ If symptoms persist, Veedma uses thresholds of Total Testosterone below 350 ng/dL and Free Testosterone below 100 pg/mL rather than relying only on the lab’s reference range. If treatment is discussed, secondary or functional hypogonadism is typically approached with Enclomiphene first, while TRT is generally reserved for primary hypogonadism or secondary cases that do not respond. You can also use Veedma for a 40 plus biomarker workup or to review existing labs.
2. Build a smarter caffeine strategy. Decide what you really want from caffeine: focus at work, a pre‑lift boost, or help on long drives. For short intense workouts, many men do well with 100 to 200 milligrams of caffeine taken 30 to 60 minutes before training.³ That could be half a Celsius, one sugar‑free Red Bull, or a strong coffee. If weight, blood sugar, or triglycerides are an issue, avoid sugar‑sweetened Red Bull most days and favor zero‑sugar options or plain coffee. Do not stack Celsius on top of multiple coffees and a pre‑workout. Avoid all energy drinks within six hours of bedtime to protect sleep and recovery.⁸ Never mix energy drinks with alcohol. If you want the cleanest “default,” choose water, unsweetened tea, or black coffee earlier in the day and build the rest of your energy around sleep and meals.
3. Monitor, adjust, and cycle. Track how you feel as you change your routine. Note heart rate, sleep quality, digestion, and gym performance. If you feel better on less caffeine, keep cutting. Many men do well with “caffeine deload” weeks where they rely on water, electrolytes, light exercise, and good meals instead of cans. If symptoms persist despite sensible caffeine use and solid sleep, see your physician to look for other causes, from thyroid and anemia to sleep apnea or clinically low testosterone.

Myth vs fact

Myth: Celsius is automatically better than Red Bull because it’s sugar‑free.

Fact: Celsius avoids sugar, which can support metabolic goals, but it still delivers a high caffeine dose and additional extracts. For some men, that higher stimulant load is more likely to trigger jitters, palpitations, or poor sleep than a lower-caffeine option. If sugar is a concern, compare it to a lower-caffeine zero-sugar drink rather than a sugary one.

Myth: Red Bull has more caffeine than Celsius.

Fact: Standard Red Bull has about 80 milligrams per small can. Many standard 12‑ounce Celsius cans list about 200 milligrams per can, though formulations vary by product and country.

Myth: If I stay under 400 milligrams of caffeine, there is zero risk.

Fact: The 400‑milligram limit is an average guideline. Some men feel jittery or notice blood pressure spikes at much lower doses, especially if they have heart or anxiety conditions.

Myth: Natural caffeine from guarana is gentler.

Fact: Your body does not distinguish between caffeine from guarana or a lab. Milligram for milligram, it stimulates the same receptors.

Myth: Energy drinks build stamina over time.

Fact: They give a short‑term lift. Heavy use can erode sleep and slow recovery, which hurts long‑term stamina and strength.

Bottom line

Many Celsius cans have more caffeine than classic Red Bull (often about 200 mg per 12 oz can vs about 80 mg per 8.4 oz can, depending on the product and country). The main health tradeoff is sugar versus stimulation: regular Red Bull brings a large sugar load, while Celsius (and zero-sugar Red Bull) avoids sugar but can be tougher on sleep, anxiety, blood pressure, and palpitations in some men. If you’re sensitive to stimulants or drink caffeine later in the day, the lower-caffeine option you can use without disrupting sleep is usually the safer everyday pick.

References

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2. Higgins JP, Tuttle TD, Higgins CL. Energy beverages: content and safety. Mayo Clinic proceedings. 2010;85:1033-41. PMID: 21037046
3. Spriet LL. Exercise and sport performance with low doses of caffeine. Sports medicine (Auckland, N.Z.). 2014;44 Suppl 2:S175-84. PMID: 25355191
4. Malik VS, Popkin BM, Bray GA, et al. Sugar-sweetened beverages, obesity, type 2 diabetes mellitus, and cardiovascular disease risk. Circulation. 2010;121:1356-64. PMID: 20308626
5. Grasser EK, Yepuri G, Dulloo AG, et al. Cardio- and cerebrovascular responses to the energy drink Red Bull in young adults: a randomized cross-over study. European journal of nutrition. 2014;53:1561-71. PMID: 24474552
6. Suez J, Korem T, Zeevi D, et al. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature. 2014;514:181-6. PMID: 25231862
7. Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011;305:2173-4. PMID: 21632481
8. Drake C, Roehrs T, Shambroom J, et al. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. 2013;9:1195-200. PMID: 24235903
9. Bhasin S, Brito JP, Cunningham GR, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. The Journal of clinical endocrinology and metabolism. 2018;103:1715-1744. PMID: 29562364