Reign Storm is a better choice than many traditional energy drinks, but calling it “healthy” stretches the meaning of the word. It delivers 200 mg of caffeine per can, uses zero-calorie sweeteners instead of sugar, and includes a handful of botanical ingredients like ginseng and green tea extract. None of those features are inherently harmful for most adults, yet the combination still carries real trade-offs for your cardiovascular system, sleep, gut health, and dental enamel that the “clean energy” branding tends to gloss over.
What Is Actually in a Can
A standard 12 oz can of Reign Storm contains 200 mg of caffeine sourced from green tea and guarana, zero sugar, zero calories, sucralose and stevia as sweeteners, B vitamins (B3, B6, B12), biotin, and small amounts of added botanicals including panax ginseng, lion’s mane extract, and CoQ10. The electrolyte content is modest. It is marketed as a lighter alternative to the original Reign Total Body Fuel line, which packs 300 mg of caffeine per can, and positioned against competitors like Celsius, Alani Nu, and ZOA.
The ingredient list reads cleaner than something like Monster or Rockstar, which load in sugar and synthetic taurine. But “cleaner” and “healthy” are different conversations. Each ingredient has its own evidence base, and the picture that emerges when you look at them individually is more complicated than a branding exercise can capture.
200 mg of Caffeine Is Not Trivial
Two hundred milligrams of caffeine is roughly what you get in two standard cups of brewed coffee. For most healthy adults, the FDA considers up to 400 mg per day generally safe. So a single Reign Storm sits at about half that ceiling, which sounds comfortable until you factor in the coffee, tea, or pre-workout you may have had earlier in the day. If you drink a Reign Storm in the afternoon and had coffee in the morning, you could easily push past 400 mg without thinking about it.
The cardiovascular effects of energy drinks go beyond what caffeine alone would predict. A systematic review of the evidence found that energy drinks are associated with a prolongation of the QTc interval, a marker of arrhythmic risk, with one study showing a 10 ms increase compared to placebo lasting up to four hours after consumption. The same review noted that systolic blood pressure could rise by as much as 4 mmHg and diastolic by 6 mmHg following energy drink intake, which places additional strain on the cardiovascular system, particularly for anyone with pre-existing heart conditions or on medications that affect heart rhythm.1PubMed Central. The Effects of Energy Drinks on the Cardiovascular System: A Systematic Review These are acute effects from single servings, not extreme doses.
The blood pressure response to caffeine itself varies from person to person. One study in healthy young adults found caffeine increased systolic blood pressure by about 17% and mean arterial pressure by roughly 11%, attributed to increased stiffness in the aorta and large blood vessels.2INDIAN JOURNAL OF APPLIED RESEARCH. EFFECT OF CAFFEINE ON SYSTOLIC BLOOD PRESSURE AND HEART RATE IN HEALTHY YOUNG ADULTS Other research, however, found no significant change in resting blood pressure or heart rate in normotensive young adults after caffeine supplementation, suggesting that habitual caffeine consumers may adapt.3Journal of Hypertension. EFFECTS OF CAFFEINE ON BLOOD PRESSURE AND HEART RATE VARIABILITY AT REST AND DURING COLD PRESSOR TEST The takeaway: if you rarely consume caffeine, a Reign Storm will likely bump your blood pressure temporarily. If you drink coffee daily, you may not feel much at all.
Does “Natural Caffeine” Matter
Reign Storm markets its caffeine as coming from green tea and guarana, which implies something gentler or more sustained than the synthetic caffeine in many competitors. The reality is less exciting. Research comparing caffeine absorption from guarana with equivalent amounts of free caffeine found no significant differences in either the rate of release or the rate of absorption across the intestine.4PubMed. Dissolution and absorption of caffeine from guarana Caffeine is caffeine. Your body handles 200 mg from guarana the same way it handles 200 mg from a synthetic source. The “natural” label is a marketing distinction, not a physiological one.
That said, green tea extract does bring along other compounds, particularly EGCG (a catechin). When combined with caffeine, EGCG-caffeine mixtures have been shown to increase 24-hour energy expenditure modestly, though one study also found they raised diastolic blood pressure by about 5 mmHg.5PubMed. Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men Caffeine on its own also increases thermogenesis, with one trial measuring a 6% bump above baseline over four hours, though green tea extract alone did not produce a significant thermogenic response compared to placebo.6PubMed. The effect of caffeine, green tea and tyrosine on thermogenesis and energy intake So any metabolism-boosting effect from Reign Storm is almost entirely driven by the caffeine, not the green tea branding around it.
What About the Green Tea Extract Safety Question
Green tea extract concentrated into supplement form has been linked to liver toxicity in case reports and animal studies, particularly when taken as a high-dose bolus on an empty stomach. Research in mice showed that a high oral dose of EGCG increased a key liver damage marker by 80-fold and depleted hepatic glutathione, an important antioxidant the liver relies on.7PubMed Central. Dietary pretreatment with green tea polyphenol, (-)-epigallocatechin-3-gallate reduces the bioavailability and hepatotoxicity of subsequent oral bolus doses of (-)-epigallocatechin-3-gallate The doses that cause problems in animal models are far higher than what a can of Reign Storm delivers, and the human case reports involve concentrated green tea dietary supplements, not beverages. Still, it is worth noting for anyone who stacks a Reign Storm on top of a green tea extract capsule for fat loss. The combined EGCG intake could become a concern.
Sucralose, Stevia, and Your Blood Sugar
Reign Storm uses sucralose and stevia to deliver sweetness without calories. Zero sugar sounds unambiguously good, especially compared to the 50+ grams in a regular Monster or Red Bull. But the research on non-nutritive sweeteners has become more nuanced than “no calories, no problem.”
One observational study of people with type 2 diabetes found that those who regularly used artificial sweeteners had higher insulin resistance scores compared to those who did not, with mean HOMA-IR values of 7.39 versus 2.6.8PubMed Central. Effect of artificial sweeteners on insulin resistance among type-2 diabetes mellitus patients That sounds alarming, but observational data cannot prove causation. People who use artificial sweeteners may already have worse metabolic health, which is why they switched to them in the first place. Meanwhile, a 12-week randomized trial specifically testing sucralose found no effect on fasting glucose, insulin, C-peptide, or HbA1c levels. The researchers concluded that the collective evidence supports sucralose having no effect on glycemic control.9PubMed. A 12-week randomized clinical trial investigating the potential for sucralose to affect glucose homeostasis These two findings are not necessarily contradictory. The controlled trial measured what sucralose does in isolation over three months; the observational study captured a broader, messier picture of real-world sweetener use. For a generally healthy person drinking one Reign Storm a day, the randomized evidence is more reassuring than the observational data is scary.
The Gut Microbiome Concern
This is the area where the science is genuinely unsettled. Non-nutritive sweeteners may alter the composition of gut bacteria, but the evidence is inconsistent. Animal studies have found decreases in beneficial bacteria like Bifidobacterium and Lactobacillus, and increases in harmful strains, potentially leading to inflammation and gut imbalance. Disruptions in short-chain fatty acid production and gut hormone signaling have also been observed in animal models.10PubMed Central. Artificial Sweeteners: A Double-Edged Sword for Gut Microbiome However, human studies generally show milder or no significant changes. A separate review of randomized controlled trials found that while some human trials did observe gut disruption, many others reported no significant impact on gut microbiota composition.11PubMed Central. Effect of Non-Nutritive Sweeteners on the Gut Microbiota
The honest summary: we do not yet know whether the amount of sucralose in a daily Reign Storm meaningfully changes your gut bacteria over months or years. The animal data is concerning, the human data is mixed, and nobody has run long-term controlled trials at the specific doses people actually consume from beverages. If you are already dealing with digestive issues, being cautious about daily sweetener intake is reasonable, but this is a watch-this-space situation rather than an established danger.
Do the Botanicals Do Anything
Reign Storm’s label highlights panax ginseng and lion’s mane mushroom extract, implying cognitive benefits. There is some research supporting ginseng’s effects on mental performance. A trial in healthy volunteers found that a 200 mg dose of panax ginseng improved performance on a sustained mental arithmetic task and reduced subjective mental fatigue during prolonged cognitive effort.12PubMed. Single doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity Longer-term studies have shown improvements in visual learning and memory in people with mild cognitive impairment after 24 weeks of supplementation.13PubMed Central. Cognition enhancing effect of panax ginseng in Korean volunteers with mild cognitive impairment: a randomized, double-blind, placebo-controlled clinical trial A broader review also found that ginseng extract can improve acute working memory in healthy people as well as those with cognitive decline.14PubMed Central. Emerging evidence that ginseng components improve cognition in subjective memory impairment, mild cognitive impairment, and early Alzheimer’s disease dementia
The problem is dosing. The studies showing cognitive benefits typically used standardized ginseng extracts at specific doses, often 200 mg or more of a concentrated extract. Reign Storm does not disclose exact amounts for its botanical blend on most labels, and energy drinks frequently use sub-therapeutic doses of headline ingredients to justify label claims. Unless the can specifies a dose that matches what the clinical literature tested, you should assume the ginseng and lion’s mane are present in token amounts. The caffeine is doing the heavy lifting for any perceived mental sharpness.
Sleep Disruption Is the Biggest Practical Risk
For most healthy adults, the single largest downside of a Reign Storm is probably what it does to your sleep, and this depends almost entirely on when you drink it. A randomized clinical trial testing the effects of caffeine dose and timing found that 200 mg (roughly one Reign Storm’s worth) did not produce statistically significant changes in objective sleep measures. But at the 400 mg dose, the effects were striking: total sleep time dropped by about 51 minutes when consumed four hours before bed, and deep sleep (the restorative stage) was cut by roughly 30 minutes even when consumed a full 12 hours before bedtime.15Sleep. Dose and timing effects of caffeine on subsequent sleep: a randomized clinical crossover trial
A meta-analysis pooling data from 24 studies confirmed the broader pattern: caffeine reduces total sleep time by about 45 minutes, cuts sleep efficiency by 7%, delays sleep onset by 9 minutes, and increases wakefulness after falling asleep by 12 minutes. Deep sleep duration dropped and light sleep increased.16PubMed. The effect of caffeine on subsequent sleep: A systematic review and meta-analysis This matters because many people reach for an energy drink precisely when they are already short on sleep. The drink fixes the afternoon slump but erodes the quality of the following night’s sleep, creating a cycle. If you are going to drink one, morning consumption is the only timing that the evidence clearly supports as low-risk for sleep.
Anxiety and Energy Drinks
Beyond sleep, there is a consistent signal linking energy drink consumption to anxiety symptoms, particularly in young men. One study found that energy drink consumption explained about 29% of anxiety scores in a sample of young adults, even after controlling for sleep quality and other caffeine intake.17PubMed Central. A Review of Energy Drinks and Mental Health, with a Focus on Stress, Anxiety, and Depression Another study among Australian young adult males found a significant association between energy drink consumption and anxiety after adjusting for confounders, though the relationship did not reach significance in females.18PubMed. Energy drink consumption is associated with anxiety in Australian young adult males
These are correlational findings, so it is possible that anxious people simply consume more energy drinks rather than the drinks causing anxiety. But caffeine is a well-established anxiogenic at higher doses, and the combination of caffeine with disrupted sleep creates a plausible mechanism. If you already tend toward anxiety, adding 200 mg of caffeine in a rapidly consumed cold beverage (most people finish a can much faster than they sip a hot coffee) could push you over a symptomatic threshold.
How It Compares to Coffee
People often ask whether they would be better off just drinking coffee instead. The cardiovascular evidence suggests coffee may actually be gentler despite having comparable caffeine. One study directly comparing energy drink and coffee consumption found that energy drinks significantly increased a marker called periodic repolarization dynamics (a measure of the heart’s electrical instability), while coffee did not alter it at all.19PubMed Central. Impact of energy drink versus coffee consumption on periodic repolarization dynamics: an interventional study A crossover study measuring acute electrophysiological effects found that energy drinks increased heart rate and QRS duration more than coffee did at the one-hour mark, and the most prominent increase in ventricular ectopy (irregular heartbeats) occurred after the energy drink, not the coffee.20European Heart Journal. Acute electrophysiological effects of energy drink, energy gum and coffee: a double-blind randomized placebo-controlled crossover study
This suggests the non-caffeine ingredients in energy drinks (possibly including taurine, sweeteners, or the combination of botanicals) may contribute to cardiovascular effects beyond what caffeine alone explains. Coffee, by contrast, delivers caffeine in a simpler chemical context. It is also typically consumed hot, which slows intake and reduces the speed of caffeine absorption. If your goal is just alertness and you have no strong preference, black coffee with nothing added is probably the healthier caffeine vehicle.
Hydration Is Not a Selling Point
Reign Storm contains some electrolytes, which might lead you to think it contributes to hydration. Caffeine, however, is a mild diuretic, and the effect depends on what you are doing. A meta-analysis found that at rest, caffeine produced a statistically significant increase in urine output, while during exercise the diuretic effect was negligible.21PubMed Central. Caffeine and diuresis during rest and exercise: A meta-analysis Research specifically examining caffeinated energy drink formulations found that caffeinated beverages retained significantly less fluid than water over four hours, with roughly 65-71% less fluid retained for caffeinated formulations that lacked additional carbohydrate-electrolyte content.22PubMed Central. Caffeinated Energy Drink Formulations Differentially Impact Hydration Versus Water: Does Habitual Caffeine Intake or Biological Sex Matter? Interestingly, formulations that included both caffeine and a carbohydrate-electrolyte blend retained fluid comparably to water. A zero-calorie, zero-sugar energy drink like Reign Storm sits closer to the poor-retention side of that equation. You are not dehydrating yourself by drinking one, but you are not hydrating effectively either. Plain water remains superior.
Enamel Erosion From Acidity
One of the less discussed risks of any energy drink is dental erosion. Energy drinks are highly acidic, with pH values consistently below 7. Lab research has confirmed that energy drinks cause statistically significant enamel erosion, comparable in some cases to cola.23PubMed Central. Influence of energy drinks on enamel erosion: In vitro study using different assessment techniques A cross-sectional analysis found that higher frequency of energy drink consumption was associated with greater enamel erosion scores and more caries experience, even after adjusting for other factors.24Journal of Bacha Khan College of Dentistry. Association between Energy Drink Consumption and Dental Enamel Erosion: A Cross-Sectional Analysis Reign Storm, like virtually all flavored energy drinks, contains citric acid as a flavoring agent. Sipping it throughout the morning bathes your teeth in acid for an extended period. If you are going to drink one, finishing it relatively quickly and rinsing with water afterward is better for your teeth than nursing it at your desk for an hour.
Who Should Skip It Entirely
Adolescents are probably the group with the clearest evidence against energy drink consumption. A review of the evidence concluded that the risk energy drinks pose to adolescent health is substantial, with adverse reactions ranging from sleep disturbances to cardiovascular events severe enough to require emergency medical treatment or poison control reporting.25PubMed Central. Risk of Energy Drink Consumption to Adolescent Health Teenagers have lower body weight, less caffeine tolerance, and still-developing cardiovascular and neurological systems. Even though Reign Storm is lower in caffeine than some competitors, 200 mg is a large dose for a 120-pound teenager.
Pregnant people are another group that should be cautious. A large study found that pre-pregnancy energy drink use was associated with a 60% higher risk of gestational hypertension, with stronger associations in older participants.26PubMed Central. Intake of Energy Drinks Before and During Pregnancy and Adverse Pregnancy Outcomes While the study did not find significant associations with preterm birth, gestational diabetes, or preeclampsia, the hypertension signal is worth taking seriously given the stakes. Current obstetric guidance already recommends limiting caffeine during pregnancy, and an energy drink is one of the easiest caffeine sources to cut.
Anyone with a pre-existing heart rhythm disorder, uncontrolled hypertension, or a history of anxiety disorders should also think carefully. The QTc prolongation data alone makes energy drinks a poor fit for people already at elevated arrhythmic risk. The benefits of Reign Storm, which ultimately amount to alertness and flavor, do not outweigh the cardiovascular and psychological risks for these groups. A broad review of the energy drink literature concluded that marketing of these products should be limited until independent research confirms their safety, particularly among vulnerable populations.27PubMed Central. Energy Drink Consumption: Beneficial and Adverse Health Effects
The Chromium and Trace Mineral Angle
Some Reign Storm varieties include trace minerals like chromium, which has a long history of being marketed as a metabolism and blood-sugar helper. The evidence for this is weak. A randomized, placebo-controlled crossover study testing a chromium-and-zinc supplement in people with type 2 diabetes found no relevant change in HbA1c, fructosamine, or fasting glucose compared to placebo.28PubMed Central. Effect of a fermented dietary supplement containing chromium and zinc on metabolic control in patients with type 2 diabetes: a randomized, placebo-controlled, double-blind cross-over study If supplemental chromium does not improve blood sugar control even in people who actually have diabetes, the trace amounts in an energy drink are not doing anything meaningful for a healthy person’s metabolism. It is another line item on the label that sounds beneficial without delivering a measurable effect.