Feeling drained by your lunch break? Yeah, me too.
Before you go straight for the coffee, consider a more potent beverage, the energy drink. They’re tasty, refreshing, and will get you more wired than any double expresso shot drink you can think of.
First, we’ll review the 10 best energy drinks on the market. Then, we’ll dive deeper into how they work to help you feel energized and focused.
SK Energy shot follows the familiar formula for shot-style energy supplements: 210 mg of caffeine per bottle, plus several B vitamins in a high dose and a proprietary energy blend, which includes amino acids and green tea extract. As is often the case, the exact ratios of the ingredients in the energy blend are not disclosed on the label, so it’s hard to compare brand to brand.
The balance of the contents of SK Energy Shot are made up of natural flavors the synthetic sweetener sucralose, and a few preservatives.
In cases like this, personal experience may be your best barometer. If you decide to use energy shots, you might need to “shop around” and try a few different brands to see how each of them affects you. Reading reviews online can only help so much; you need to remember that the same supplement can affect different people in different ways.
Like some of its competitors, SK Energy Shot contains 30 mg of niacin per bottle, so if you want to avoid itching, flushing, and tingling, avoid taking it with any other supplement that contains niacin.
Copycats don’t get much more blatant than this—6-Hour Power is obviously an attempt to upstage 5-Hour Energy as king of the single shot energy supplement category. But how does it stack up? Is it really one hour better?
The only sane thing to do is a head-to-head comparison. In terms of caffeine, 6-Hour Power actually contains substantially less, at 130 milligrams versus 200. The B-vitamin content is nearly identical. Both supplements contain the same amount of vitamin B6 and B12, as well as folic acid.
The only difference is in niacin; 6-Hour Power contains 20 mg while 5-Hour Energy contains 30mg. This difference might shift the odds in favor of 6-Hour Power, since it’s less likely to cause flushing, itching, and tingling.
Both supplements also contain a proprietary “energy blend.” Since these are not nutrients, their exact quantities are not listed on the label, but the ingredients are largely the same: taurine, glucouronic acid, malic acid, N-acetyl L-tyrosine, and L-phenylalanine.
The only other significant ingredient difference is that 6-hour Power contains an enzyme blend that is supposed to help with digestion, which might reduce the churning stomach feeling you get if you take an energy supplement after a large meal.
On balance, despite the name, 6-Hour-Power is a bit tamer than 5-Hour Energy. It provides less caffeine and less niacin, so it may give you a steadier stream of energy, but it’s not likely to provide a full boost for its eponymous duration.
Like Red Bull, this supplement spawned an entire category of energy products, the single-shot liquid energy supplement. With almost 200 milligrams of caffeine, 5-Hour Energy provides a hefty jolt of the stimulant to get you going.
As for the name, five hours is actually a pretty good bet for its duration—the rate at which your body removes caffeine from your bloodstream is about five hours per half-dose, meaning that half the caffeine you take in has been removed and excreted within five hours of taking a dose (1).
This varies a bit from person to person; women who are on birth control are known to have a much longer elimination timeframe. For them, this might turn into “12-hour energy,” so be careful!
5-Hour Energy also provides a massive dose of B-vitamins, some in amounts that might be risky if you already get a lot of B-vitamins in your diet. Niacin, also known as vitamin B3, is provided at a dose of 30 milligrams.
The US Food and Nutrition board sets an upper limit of 35 milligrams per day; doses above this can result in flushing, tingling, or itching (2). Because of this, it is not recommended that you take more than one five-hour energy during the day, nor should you combine it with other energy drinks or supplements that provide B-vitamins.
This is a lesser-known competitor in the single-shot energy supplement category, but it’s on par with 5-Hour Energy when it comes to energy and nutrients. Worx provides 210 mg caffeine, alongside the expected taurine-containing energy blend, which also features many of the same ingredients as 5-hour Energy.
The blend of amino acids is slightly different, but the philosophy is the same: provide the body with all of the basic building blocks it needs to accomplish biological tasks. The vitamin content in Worx is identical to that of 5-Hour Energy, from the B-vitamins all the way down to folic acid.
One win for Worx is that it only uses natural flavorings, not a combination of natural and artificial flavorings like many of its competitors. One drawback is that it does use caramel color and yellow number 5 as coloring agents, which might be a turn-off to some people.
Beyond these minor points, Worx and 5-Hour Energy are essentially identical, and carry the same caveats—limit yourself to one per day, and be careful when it comes to combining it with other B3 (Niacin) containing energy supplements.
Red Bull is practically the grand-daddy of all energy drinks. The wildly popular formulation is available all across the world. Its energy recipe is based around a combination of sugar, caffeine, taurine, and B-vitamins.
Each 8.4 fluid ounce can provides 80 milligrams of caffeine—just slightly less than what’s in an average cup of coffee.
Taurine, an amino acid that’s plentiful in your nervous system, is supposed to help your nerves grow and stay healthy.
The B vitamins included in Red Bull encompass B3, B5, B6, and B12. These are provided with the hopes of enhancing energy production and efficiency at the cellular level in your body, and are responsible for the mild tingling feeling that you might get when you drink several B vitamin-containing energy drinks.
Red Bull also comes in a sugar-free version, which substitutes aspartame in place of sugar. Real sugar can be burned by your body for energy, but if you’re not doing a physically engaging activity, like working out or hiking, the sugar is going to do you more harm than good. In this case, the sugar-free version of Red Bull is the better choice—assuming you’re okay with artificial sweeteners.
Powder-form single-use energy drink mixes became popular a few years ago, and Zipfizz is one of the best-selling energy supplements in that category. It comes in single-use tubes which contain a powder. Dump it into your water bottle and you have a ready-made energy drink.
Zipfizz contains 100 mg of caffeine in the form of green tea extract and provides a well-rounded blend of vitamins and minerals—it’s almost like drinking a daily multivitamin. What really jumps out is the vitamin B12 content— 42,000% of your recommended daily intake!
According to data from the National Institutes of Health, absorption of vitamin B12 is drastically reduced at high doses, so much of this may be wasted (3). However, there is no listed tolerable upper limit for vitamin B12, so it’s still safe, even in a tremendously high dose.
The reason for this is that there are no known adverse effects in humans from taking very high doses of vitamin B12. However, it’s still an open question as to whether a high dose of vitamin B12 is actually going to help you feel more energized. As most energy drinks list on their label, “results may vary.”
The tall can and flashy styling of Rockstar Sugar Free communicates its nature: it’s more of a drink than a supplement.
It’s nearly non-caloric, providing only 20 calories per 16 ounce can. It provides a higher-than average 160 milligrams of caffeine per can, and a normal amount of B vitamins: 200% of your recommended daily intake of niacin, vitamin B6, pantothenic acid, and 400% of your recommended daily intake for riboflavin.
On top of this, it includes herbal extracts from a few plants that are supposed to give you an energy boost. These include guarana seed, panax, ginseng root, and milk thistle extracts—fairly common ingredients among liquid energy drinks.
If coffee makes your stomach quiver, or if you like sugar-sweetened energy drinks but want to watch your weight, Rockstar Sugar Free is a good choice.
It’s not the most efficient delivery vehicle if your only goal is to load up on caffeine, vitamins, and herbal energy extracts, but the larger can provides a more steady energy output than downing a single shot energy supplement that’s loaded up with twice as much caffeine and ten times as much B vitamins and herbal extracts.
Redline VPX is another lesser-known energy shot; its main selling point is that in includes small amounts of calcium, magnesium, and potassium—electrolytes which you may lose when you sweat a lot—in addition to caffeine and the usual blend of amino acids.
Additionally, it contains several herbal extracts which are purported to have energy-boosting qualities.
These herbal supplements include yohimbe, toothed clubmoss, yerba mate extract, green tea extract, and 5-HTP. Some of these, like yerba mate (used in an herbal drink throughout South America) have a long tradition of being used as energizing herbal remedies, while others, like toothed clubmoss, are lesser known.
Outside of its herbal ingredients, Redline VPX is similar to many other energy shots. It is flavored with artificial and natural flavors, along with sucralose, an artificial sweetener.
Although it does contain 320 mg of caffeine per bottle, there are more straightforward ways to get caffeine. If you use Redline VPX, it should be for the herbal supplements it contains. Right now, there is little or no research on the effects of almost all of its ingredients, so your results might vary. Green tea extract is one ingredient with good evidence for its efficacy (4), but the rest are shrouded in mystery.
Through aggressive sponsorship and marketing, Monster Energy has grown from a cult-following energy drink to one of the biggest juggernauts in the genre.
Unlike Red Bull, which comes in small, 8.4oz cans that are easily downed in a few gulps, Monster Energy comes in a larger 16 ounce can, clearly meant for longer sustained consumption. It’s also heavily sugared, and in composition is more similar to a can of soda than an energy drink.
A full can of Monster Energy contains 210 calories, all of which come from sugar. Unless you’re doing something highly active, like a team sports competition or a long hike, this amount of sugar is likely excessive.
It contains a moderate 160 milligrams of caffeine, along with 200% of your recommended daily intake of vitamins B2, B3, B6, and B12. It contains a few one-off extracts, like ginseng, along with a few amino acids to give your body the building blocks for protein.
Because of these reasons, Monster Energy is probably the best choice only if you are specifically looking for a non-carbonated, caffeinated drink that also provides vitamins, amino acids, and a large amount of simple sugar that you’ll be burning for energy.
Amp Energy is an increasingly popular competitor in the standard-sized energy drink category. It’s got many of the hallmarks of that genre: 16 ounce can and 150 milligrams of caffeine, but it’s flavored more like a traditional soft drink than many other energy drinks.
It has very little in the way of B-vitamins: only 20% of your daily recommended intake, which is ten times lower than that of many of its competitors.
It is also flavored with real sugar, meaning each can packs 220 calories, all of them from sugar. Good news if you’re doing a 50-mile bike ride, but bad news if you are sitting at your desk.
Amp Energy has a few of the usual additional ingredients that accompany large canned energy drinks, like guarana seed extract, ginseng extract, and taurine, but does not go out of its way to advertise them, nor does it list their concentrations.
For these reasons, it finds itself lower on the rankings than similar drinks.
Part II: What should you look for in an energy drink and how do they work?
Energy drinks rocketed to popularity after an obscure local drink in Thailand was reformulated and marketed to a global audience. That drink, of course, was Red Bull, which is a market-dominating juggernaut among energy drinks.
More recently, competition has gotten fierce among companies vying for a share of the market.
Benefits of energy drinks
Broadly speaking, all energy drinks are caffeinated and usually provide something beyond just caffeine to boost your energy levels. The most common among these extra ingredients are B vitamins, taurine, green tea extract, and herbal extracts like yerba mate extract and guarana seed extract.
There are varying levels of evidence that each of these can enhance your energy levels
Still, caffeine has the biggest role when it comes to boosting energy. Caffeine is a stimulant, meaning it kick-starts your metabolism, increases your alertness, improve your reaction time, and increase your physical performance during exercise.
The amount of caffeine you consume is related to the strength of these effects, but as always, there can be too much of a good thing!
Taurine is another staple ingredient of energy drinks. It derives its name from the fact that it was first isolated in the liver bile of oxen in the 1800s, but it’s far more common in your body than you’d think. It plays a critical role in the development of the nervous system and ensuring its proper function.
By including taurine in energy drinks alongside caffeine, the hope is that the energy drink will elevate your nervous system to a higher performing level than with caffeine or taurine alone.
A highly detailed study published in 2012 by Grace E. Giles and other researchers at Tufts University attempted to tease out how caffeine and taurine interact to produce the reported benefits of energy drinks (5).
In their study, a group of volunteers were given a randomized series of four treatments: caffeine only, taurine only, caffeine and taurine, and a true placebo. After administering each treatment, the researchers subjected the study subjects to a battery of cognitive tests.
As expected, caffeine had a consistent and significant beneficial effect on tasks like short term memory and reaction time. Taurine had some beneficial effects too, but even when combined with caffeine, it contributed only in a small, varied, and unpredictable way to cognitive performance.
This study didn’t test all of the aspects that energy drinks purport to improve; physical performance or muscular strength or coordination, for example, were not evaluated at all.
However, this does give us some evidence that we shouldn’t consider taurine content to be the biggest factor in evaluating the benefits of an energy drink.
Another common ingredient among energy drinks is B vitamins. These play a key role in the functioning of your nervous system too. Like with taurine, the hope is that the B vitamins will interact synergistically with the caffeine to boost your energy levels and alertness to a higher level than possible with just caffeine.
One study published in 2012 in the journal Nutrition & Metabolism by a group of scientists led by Brandon D. Spradley found that a pre-workout supplement that combined caffeine and B-vitamins, along with a few other ingredients, did boost performance on agility and lower body muscular endurance during an exercise testing session (6).
However, it did not evaluate the role of each ingredient individually—it was compared against a true placebo, not a caffeine-only supplement.
Though energy drinks seem like a food or drink, it’s important to remember they’re really more like a supplement. Too much can cause problems for your health and well-being. In most cases, you shouldn’t drink more than two energy drinks per day.
It depends somewhat on the brand—drinks with lower caffeine contents and lower amounts of niacin are safer to consume more often, but a highly caffeinated or niacin-rich drink consumed more than twice daily could cause problems.
Energy drinks are formulated in a “pre-made” dose; they’re already calibrated for what you need. Usually, just one should do the trick!
Side effects of energy drinks
Like with many biologically active compounds, there are drawbacks to consuming too much of several of the compounds in energy drinks. The two you need to be most concerned about are caffeine and niacin (vitamin B3).
Caffeine is, of course, a stimulant, and in high doses, it can have deleterious effects on your body: jiggers, a racing heartbeat, and nausea are some common side effects of consuming too much caffeine.
In rare cases, high doses of caffeine from energy drinks have caused abnormal heart rhythms, which can sometimes even lead to death, as described in a case study published in 2013 by doctors in Turkey (7).
Medical reports caution that overuse of energy drinks, especially when combined with aggressive, strenuous physical activity, can cause heart problems even in young, healthy people (8).
According to the Mayo Clinic, most people can handle up to 400 mg of caffeine per day (9). Many people, of course, consume more than this, and it’s likely that there is a wide range in individual tolerance, but this guideline is a good place to start.
Niacin, also known as vitamin B3, is also known to cause some problems when consumed to excess. Doses of 35 mg or more are known to cause flushing, redness, itchiness, and a tingling sensation (10).
Some energy drinks come very close to this amount of niacin, so to avoid this, you shouldn’t take any other supplements with niacin in them, or consume more than one energy drink per day if it has a lot of niacin.
Largely speaking, energy drinks are an effective and safe way to boost your energy levels, increase your alertness, and increase your performance on physical and cognitive tasks.
Evaluate your options carefully, since the range of energy drink products on the market have some notable differences in their ingredients. Choose the right one to fit your needs.