NOS Energy Drink isn’t going to harm you from a single can, but regular consumption carries real health risks, primarily from its caffeine content, sugar load, and stimulant combination. A standard 16-ounce can contains 160 mg of caffeine and 54 grams of sugar, which is enough to raise your blood pressure, spike your blood glucose, and disrupt your sleep if you’re not careful about how much or how often you drink it.
What’s Actually in a Can of NOS
The 160 mg of caffeine in a 16-ounce NOS puts it right at the level of a strong cup of coffee. That’s 40% of the FDA’s 400 mg daily limit for adults, the threshold generally not associated with negative health effects. So one can keeps you within safe territory, but add a coffee or two throughout the day and you’re pushing past that ceiling quickly.
Beyond caffeine, NOS contains taurine, guarana extract, and inositol. Guarana is itself a plant-based stimulant that contains caffeine, meaning the total stimulant load in each can is slightly higher than the 160 mg listed on the label. The B-vitamin content is also notable: a single can delivers 240% of your daily value for B6 and 500% for B12. While excess water-soluble vitamins are generally excreted by your body, consistently mega-dosing B6 over time has been linked to nerve-related side effects.
Then there’s the sugar. At 54 grams per can, NOS contains more sugar than a regular Coca-Cola. That’s over twice the American Heart Association’s recommended daily limit for women (25 grams) and well above the limit for men (36 grams), all in a single serving.
Effects on Your Heart and Blood Pressure
Energy drinks like NOS have a measurable effect on your cardiovascular system, even if you’re young and healthy. Research from the Mayo Clinic found that healthy adults aged 19 to 40 experienced a marked rise in blood pressure within 30 minutes of drinking a single energy drink compared to a placebo. The effect was more than doubled in people who don’t regularly consume caffeine.
This matters because the combination of caffeine plus guarana plus taurine appears to affect the cardiovascular system more aggressively than caffeine alone. If you already have elevated blood pressure, or if you’re not a regular caffeine user, one can of NOS could produce a noticeable spike. Over time, repeated blood pressure spikes contribute to long-term cardiovascular strain. The Mayo Clinic researchers specifically cautioned that energy drinks “may increase the risk of cardiovascular problems, even among young people.”
Blood Sugar and Metabolic Impact
The 54 grams of sugar in a regular NOS triggers a rapid rise in blood glucose. Research published in the Canadian Journal of Diabetes found that caffeinated energy drinks cause blood sugar to spike faster and stay elevated longer than beverages with the same sugar content but no caffeine. In other words, the caffeine in NOS doesn’t just give you a buzz; it actively slows your body’s ability to bring blood sugar back to normal levels.
Regular consumption of caffeine-containing beverages has also been associated with insulin resistance, which is a precursor to type 2 diabetes. For anyone already managing blood sugar issues or at risk for metabolic problems, the combination of high sugar and caffeine in NOS is particularly problematic. Even for healthy people, drinking one daily means consuming an extra 378 calories and over 50 grams of pure sugar before you’ve eaten a thing.
Anxiety, Sleep, and Overstimulation
The guarana in NOS works alongside the added caffeine, meaning both stimulants hit your nervous system simultaneously. Memorial Sloan Kettering Cancer Center flags insomnia as a known side effect of guarana, and notes that combining guarana with other stimulants “may not be safe.” At high intake levels, guarana-containing products have been associated with heart rhythm changes, agitation, and in rare cases involving young adults, seizures.
For most people, a single NOS won’t cause anything that dramatic. But if you’re sensitive to caffeine, prone to anxiety, or drinking NOS in the afternoon or evening, you can expect trouble falling asleep, restlessness, or a racing heart. These effects compound if you’re also drinking coffee, tea, or pre-workout supplements during the same day.
NOS Zero Sugar: A Better Option?
NOS does make a zero-sugar version that swaps sugar for erythritol, sucralose, and acesulfame potassium. This eliminates the blood sugar spike and cuts the calorie count dramatically, which is a genuine improvement for metabolic health. The caffeine content remains the same at 160 mg, so all the cardiovascular and stimulant-related concerns still apply.
Erythritol is a sugar alcohol that your body absorbs but doesn’t metabolize for energy, so it has minimal caloric impact. Sucralose and acesulfame potassium are FDA-approved artificial sweeteners found in thousands of products. If sugar is your main concern, the zero-sugar version is meaningfully better. If caffeine and stimulant load is your concern, it’s no different from the original.
Who Should Avoid NOS Entirely
The American Academy of Pediatrics is clear that caffeine and other stimulants in energy drinks “have no place in children’s and adolescents’ diets.” The CDC echoes this, and the National Federation of State High School Associations recommends young athletes avoid using energy drinks for hydration. These aren’t vague suggestions; they reflect the fact that developing bodies process stimulants differently, and the risks of heart rhythm disturbances and anxiety are higher in younger people.
Adults with high blood pressure, heart conditions, anxiety disorders, or diabetes should also approach NOS with caution. Pregnant and breastfeeding women are typically advised to stay well below 200 mg of caffeine per day, which means a single NOS would nearly max out that allowance with no room for any other caffeine source.
The Bottom Line on Occasional vs. Daily Use
An occasional NOS, once or twice a week, is unlikely to cause lasting harm for a healthy adult who isn’t sensitive to caffeine. The problems start with daily use. Drinking one NOS every day means 1,120 mg of extra caffeine per week, 378 grams of sugar (in the regular version), and repeated blood pressure spikes that your body never fully recovers from before the next one. Over months and years, that pattern raises your baseline risk for hypertension, weight gain, insulin resistance, and poor sleep quality.
If you rely on NOS for energy, it’s worth asking what’s driving the fatigue in the first place. Chronic sleep debt, dehydration, and poor nutrition are the most common culprits, and none of them improve with a can of energy drink. They just get masked until the caffeine wears off.