Does 5-Hour Energy Actually Work? What the Trials Found
Roon Team
Does 5-Hour Energy Actually Work? What the Trials Found
Yes, 5-Hour Energy works, but only to the extent that 200 mg of caffeine works, roughly two cups of coffee. Three placebo-controlled trials tested the actual product, and none found it outperformed plain caffeine on cognition, mood, or exercise performance. The B vitamins pass through you. The niacin explains the face flush. The "energy blend" is undosed.
Key Takeaways
- Caffeine is the only ingredient with measured evidence of effect in 5-Hour Energy.
- A head-to-head trial (n=20) found the shot no better than 200 mg of caffeine alone on cognitive tests or subjective energy at 1, 3, and 5 hours.
- B6 at 2,353% and B12 at 20,833% of daily value have no evidence of benefit in non-deficient adults. They exit through urine.
- Niacin at 30 mg is listed as niacinamide, a form that does not normally cause flushing, yet the brand warns some users may experience it.
- The remaining "energy blend" lists six ingredients at undisclosed individual doses.
The Label, Line by Line
| Ingredient | Amount per shot | % Daily Value | What the evidence says |
|---|---|---|---|
| Caffeine | 200 mg (Regular) / 230 mg (Extra Strength) | N/A | Standard research dose; drives the alertness effect |
| Niacin (B3) | 30 mg | 188% | Listed as niacinamide (a non-flushing form); UL for all niacin forms is 35 mg/day. Brand still warns of flush. |
| Vitamin B6 | 40 mg | 2,353% | No cognitive benefit in non-deficient adults |
| Vitamin B12 | 500 mcg | 20,833% | No cognitive benefit in non-deficient adults |
| Energy blend (taurine, glucuronolactone, tyrosine, phenylalanine, citicoline, malic acid, caffeine) | Under 2 g total | N/A | Individual doses undisclosed; cannot be independently assessed |
| Calories | 4 | ||
| Sugar | 0 g | Sugar-free |
Bottle size: 1.93 fl oz. Price: $2.83 per shot (12-pack, Extra Strength, from the brand's own store).
Sources: 5-Hour Energy caffeine facts, brand FAQ.
The Ingredient That Works: Caffeine
Two hundred milligrams is a standard research dose, about two 8 oz cups of coffee, within the FDA's 400 mg/day guideline. Extra Strength is 230 mg. The brand caps intake at two bottles per day spaced several hours apart, but two Extra Strength shots is 460 mg, past the FDA line before you count anything else.
The brand's own caffeine-facts page names caffeine as a primary driver of alertness within its proprietary blend. And when a 2015 crossover trial (Bloomer et al., n=20) compared the full shot against 200 mg of caffeine alone and a placebo, neither improved subjective feelings or cognitive performance on Trail Making and Digit Symbol tests at 1, 3, and 5 hours. The shot did nothing plain caffeine did not do.
The Ingredients That Pass Through: B Vitamins
Vitamin B6 at 2,353% of daily value and B12 at 20,833% look dramatic on a label. But water-soluble vitamins above what your body needs get excreted in urine, which is why it turns neon yellow after a shot.
A 2021 Nutrients meta-analysis (16 RCTs, 6,276 participants) found no evidence that B12 alone or B-complex supplementation improved any subdomain of cognitive function in people without advanced neurological disorders. Only one trial even measured fatigue, so there was no pooled estimate for the claim that matters most at a gas-station counter.
The brand's FAQ states these amounts "are within safe limits." No counter-claim on safety here. The point is simpler: no evidence these doses help cognition or energy in someone who is not deficient. (See also: B vitamins for brain health, vitamin B12 and brain fog, the B-vitamin padding pattern in other products.)
The Ingredient You Feel but Did Not Want: Niacin
The hot face and tingling arms some people get after a shot are not an allergic reaction. They are commonly called niacin flush. The label lists niacin as niacinamide, a form that does not normally cause flushing at this dose, yet the brand's own FAQ warns some users may experience it. The discrepancy is unresolved.
The shot contains 30 mg of niacin. The NIH Office of Dietary Supplements states that supplements with 30 mg or more of nicotinic acid can cause flushing, but the 5-Hour Energy label specifies niacinamide, a form that does not normally trigger this response. The NASEM Dietary Reference Intakes set the adult UL at 35 mg/day for all niacin forms. Despite the niacinamide label, the brand's FAQ acknowledges flushing in some users.
The brand's FAQ acknowledges the effect: some people are sensitive to elevated niacin, which "can result in an increase in blood flow near the skin or 'flushing'" that "will generally go away in a few minutes." If it persists or you feel unwell, see a clinician.
The Blend Nobody Can Evaluate
Below the B vitamins sits the "energy blend": taurine, glucuronolactone, tyrosine, phenylalanine, citicoline, and malic acid, combined with caffeine, totaling 1,870 mg (Regular) to 2,000 mg (Extra Strength). Individual doses are not disclosed.
Caffeine takes up 200 mg of that total. The remaining six ingredients split roughly 1.67 to 1.77 grams among them. Without milligram breakdowns, no one can check whether any reaches a research-relevant dose. You cannot evaluate what you cannot measure.
Three Trials, Three Nulls
| Study | Year | n | Design | Finding |
|---|---|---|---|---|
| Bloomer et al. | 2015 | 20 | Randomized crossover: shot vs. 200 mg caffeine vs. placebo | No cognitive or subjective gain over caffeine or placebo; diastolic BP up |
| Physiology & Behavior | 2015 | 24 | Double-blind crossover: shot vs. placebo, five computer-based tasks hourly for 5 h | No cognitive improvement "despite a high level of perception that it was working" |
| WKU / Int. J. Exercise Science | 2016 | 23 | Randomized double-blind crossover before treadmill VO2max | No effect on peak VO2, peak heart rate, or time to exhaustion |
Three trials, three nulls. The second is especially telling: subjects believed the shot was working even when their performance said otherwise.
"Five Hours" and "No Crash"
The product's name implies a specific duration. Caffeine's half-life averages 5 to 6 hours in healthy adults, meaning half of a 200 mg dose is still circulating at that mark. That is true of any 200 mg caffeine source. A caffeine half-life calculator can estimate your personal timeline, and how long do energy drinks last compares formats head to head.
The "no crash" claim had legal consequences. In 2014, Oregon, Washington, and Vermont sued the makers over claims including "hours of energy, no crash later." A Washington judge found Consumer Protection Act violations and ordered about $4.3 million in penalties and fees. The Vermont case settled for $308,000 with no admission of wrongdoing; Oregon's case was resolved without a published adverse judgment.
Lab-Measured Caffeine vs. the Label
For years the label did not print a caffeine number. CSPI measured 207 mg. A March 2011 Consumer Reports article reported lab-tested caffeine of 207 mg in a Regular shot (as cited on Wikipedia; the CR article is paywalled). Caffeine Informer has separately reported 215 mg Regular and 242 mg Extra Strength, but neither figure has a freely available primary source. The brand's caffeine-facts page now lists 200 mg Regular, 230 mg Extra Strength. The gaps are modest, but the history underlines why printing the number matters.
Should You Worry About Safety?
The FDA investigated adverse-event reports involving 92 patients, 33 hospitalizations, and 13 deaths that cited 5-Hour Energy. The FDA cautioned that a filed report does not mean the product caused the adverse episode. No regulatory action followed.
At 200 to 230 mg per shot, the caffeine sits within the FDA's 400 mg/day guideline for most healthy adults. The risk concentrates in stacking: two Extra Strength shots plus a morning coffee can push well past 400 mg before lunch.
Choosing an Energy Format That Shows Its Work
The answer to "does 5-Hour Energy work?" is straightforward: 200 mg of caffeine works, and nothing else in the bottle has evidence of adding to it. The B vitamins are expensive urine. The niacin is an unwanted side effect. The proprietary blend is a black box. If you are paying for energy, pay for a product that prints every milligram on the label.
Frequently Asked Questions
Does 5-Hour Energy actually work?
It works to the extent that 200 mg of caffeine works. A 2015 crossover trial (n=20) found the shot no better than 200 mg of plain caffeine on cognitive tests or subjective feelings at 1, 3, and 5 hours. The B vitamins and energy blend showed no measurable contribution.
How long does 5-Hour Energy last?
About as long as any 200 mg caffeine source. Caffeine's half-life averages 5 to 6 hours, so you will have roughly 100 mg still circulating at that point. The "five hours" in the name tracks caffeine pharmacokinetics, not a special formula property.
Why does 5-Hour Energy make my face hot?
Niacin flush. The shot has 30 mg of niacin (B3) listed as niacinamide, a form that does not normally cause flushing, yet the brand's FAQ warns some users may experience it. It typically resolves within minutes. If it persists, see a clinician.
Is 5-Hour Energy just caffeine?
Functionally, yes. The bottle also contains B vitamins, niacin, and a proprietary "energy blend," but none have shown measurable benefit in the product's own trials. The brand's own caffeine-facts page names caffeine as a primary driver of alertness within its proprietary blend.
Does 5-Hour Energy make you crash?
Any caffeine source can produce a perceived drop as the stimulant clears. A Washington judge found the "no crash" ad claim violated the Consumer Protection Act in 2017; the Vermont case settled for $308,000 with no admission of wrongdoing, and Oregon's case was resolved without a published adverse judgment. Whether you feel a crash depends on dose, sleep debt, and individual metabolism.
Is it bad to take two 5-Hour Energy shots in a day?
Two Regular shots is 400 mg of caffeine, right at the FDA's daily guideline. Two Extra Strength shots is 460 mg, above it. The brand recommends a maximum of two per day spaced several hours apart, but that math ignores any other caffeine you consume. Track your total intake.
If the Caffeine Is the Only Active, Buy the Caffeine
One ingredient does the work. The rest is padding you excrete or feel on your face. So the question becomes: how do you get caffeine in a format where every ingredient is dosed, printed, and has a reason to be there?
Roon is a sublingual pouch with four disclosed ingredients: 80 mg caffeine, 60 mg L-theanine, 25 mg methylliberine (Dynamine), and 5 mg theacrine (TeaCrine). No niacin. No B vitamins. No proprietary blend. Zero sugar (it contains sucralose), zero nicotine. The 80 mg dose is deliberate. A randomized, double-blind, crossover PK study (n=12) found that methylliberine co-administration cut caffeine's oral clearance from 41.9 to 17.1 L/hr and extended its half-life from 7.2 to 15 hours, with no increase in peak concentration. That study used 100 mg methylliberine with 150 mg caffeine (roughly 4x Roon's methylliberine and 1.9x the caffeine), so the magnitude will be smaller in a pouch. The mechanism is directionally the same: lower caffeine, stretched longer, felt for 6 to 8 hours. Stop at least 8 hours before bed.
Two pouches is 160 mg, well under the 400 mg line. Pricing starts at $0.61 per pouch on the 12-tin subscription, or $1.00 per pouch one-time ($15.00 per tin, 4-tin minimum), against $2.83 per 5-Hour Energy shot. Roon is not a replacement for sleep. But if you are paying for caffeine, you should know what is in the bottle. Try Roon.
Related from Roon
- How Much Caffeine Is in a Cup of Coffee?
- How Long Does Caffeine Stay in Your System?
- B Vitamins for Brain Health
- How Long Do Energy Drinks Last?
Written by Roon Team
