Can I Drink Two NOS Energy Drinks a Day? What You Need to Know

November 13, 2025 •

4 min read

According to the FDA, most healthy adults can consume up to 400 mg of caffeine per day without negative effects. However, drinking two NOS energy drinks a day puts you right at that limit, potentially exposing you to adverse health risks depending on your individual sensitivity and other caffeine sources.

Quick Summary

Consuming two NOS energy drinks daily delivers a high dose of caffeine and sugar, posing various health risks, including cardiovascular issues, insomnia, anxiety, and blood sugar spikes. It is vital to consider individual health factors and overall caffeine intake before making this a regular habit.

Key Points

High Caffeine Intake: Two NOS energy drinks contain 320 mg of caffeine, approaching the FDA's 400 mg daily limit for healthy adults.
Increased Health Risks: Regular consumption can lead to cardiovascular strain, including heart palpitations, increased blood pressure, and potential arrhythmias.
Psychological Effects: Excessive caffeine and stimulants can cause anxiety, nervousness, irritability, and disrupt healthy sleep patterns.
Metabolic and Digestive Issues: The high sugar content can cause blood sugar spikes, crashes, and increase the risk of digestive upset and type 2 diabetes.
Healthier Alternatives: Long-term, more reliable energy comes from proper sleep, hydration, balanced nutrition, and regular exercise, not from energy drinks.
Consider Your Sensitivity: Individual tolerance to caffeine varies, and those who are more sensitive may experience stronger adverse effects from two NOS drinks.

Understanding the Caffeine Content

Each 16 oz can of NOS Energy Drink contains approximately 160 mg of caffeine. Drinking two of these in one day would result in a total caffeine intake of 320 mg. While this amount is below the 400 mg daily limit cited by the FDA for most healthy adults, it is still a substantial dose. The potential issues arise when considering other sources of caffeine, your personal health, and the other stimulating ingredients in NOS.

More Than Just Caffeine: The Other Ingredients

Energy drinks like NOS contain a blend of ingredients designed to enhance performance, which can amplify the effects of the caffeine. Common components include:

Taurine: An amino acid that regulates heart rate and muscle contractions.
Guarana Extract: A natural source of caffeine that can extend and intensify the stimulant effects.
B Vitamins: Included for their role in energy metabolism, though excess intake is often unnecessary for those with a balanced diet.
High Fructose Corn Syrup: A major source of the sugar and calories, which can lead to a subsequent energy crash.

Short-Term and Long-Term Health Risks

Even when staying within the FDA guidelines, consuming two energy drinks daily can lead to a host of short-term and long-term health issues. The potent combination of stimulants and sugar can impact various bodily systems.

Cardiovascular Strain

Multiple studies have linked energy drink consumption to adverse cardiovascular events. The combination of caffeine and other stimulants can significantly increase your heart rate and blood pressure, potentially causing:

Heart Palpitations: A sensation of a rapid, strong, or irregular heartbeat.
Cardiac Arrhythmias: Abnormal heart rhythms that can be dangerous, especially for individuals with underlying heart conditions.
Hypertension: Consistent elevation of blood pressure over time, which increases the risk of heart attack and stroke.

Neurological and Psychological Effects

Excessive caffeine intake affects the central nervous system, leading to several psychological and neurological issues. Consuming two NOS drinks can trigger:

Increased Anxiety and Nervousness: Caffeine triggers the release of adrenaline, which can lead to jitteriness and heightened anxiety.
Insomnia and Sleep Disruption: The stimulating effects of caffeine can interfere with your sleep cycle, especially if consumed later in the day.
Headaches: Abruptly stopping caffeine can lead to withdrawal symptoms, including headaches.

Digestive and Metabolic Problems

Energy drinks can also take a toll on your digestive system and metabolic health, particularly due to their high sugar content.

Digestive Upset: The acidic nature of the drink combined with caffeine's effect can cause stomach irritation, nausea, and diarrhea.
Blood Sugar Spikes: The high amount of sugar can cause rapid increases in blood glucose, which can lead to a subsequent energy crash and increase the risk of type 2 diabetes over time.

Comparison Table: NOS vs. Healthier Alternatives


Feature	Two 16oz NOS Energy Drinks	Two 16oz Coffees	Two 16oz Green Teas	Water
Caffeine (mg)	320	~200-400	~60-100	0
Sugar	Very High	0 (typically)	0 (typically)	0
Taurine & Guarana	Yes	No	No	No
Calories	Very High	Low	Very Low	0
Hydration	Dehydrating	Mildly Dehydrating	Mildly Dehydrating	Hydrating
Nutritional Value	Minimal	None	Moderate	High
Long-Term Risk	High	Moderate	Low	None

How to Reduce Reliance on Energy Drinks

If you find yourself regularly needing two or more energy drinks to get through the day, it may indicate underlying issues with fatigue or poor lifestyle habits. There are healthier, more sustainable ways to boost your energy:

Prioritize Sleep: Ensure you get 7-9 hours of quality sleep per night. Sleep is the most effective natural energizer.
Stay Hydrated: Dehydration can cause fatigue. Drinking plenty of water throughout the day is a simple but effective solution.
Eat Balanced Meals: A diet rich in whole grains, lean protein, and fruits and vegetables provides sustained energy without the sugar crash associated with energy drinks.
Exercise Regularly: Regular physical activity, even moderate exercise, can significantly improve energy levels and mood.

Conclusion: Moderation and Awareness are Key

While an occasional NOS energy drink is unlikely to cause significant harm for a healthy adult, making a habit of drinking two per day can lead to serious health complications. The cumulative effects of high caffeine, sugar, and other stimulants put a strain on your cardiovascular, neurological, and metabolic systems. It is crucial to be mindful of your total caffeine intake from all sources and to listen to your body. Instead of relying on a can for a quick fix, consider adopting healthier, more sustainable energy-boosting strategies. Ultimately, for your long-term health, limiting your intake to an occasional drink is the safer and wiser choice. If you experience any negative side effects, it's best to reduce your consumption or stop entirely and consult a healthcare professional.

Visit the U.S. Food and Drug Administration for more details on caffeine consumption.

Frequently Asked Questions

While 320 mg is under the FDA's 400 mg daily limit, it can still cause negative side effects, especially if you are sensitive to caffeine or consume it from other sources.

Common side effects include heart palpitations, increased heart rate, high blood pressure, anxiety, restlessness, insomnia, and digestive problems.

Yes, excessive consumption of energy drinks, including two NOS, can increase heart rate, raise blood pressure, and cause dangerous arrhythmias, particularly in individuals with pre-existing heart conditions.

The jitters are a result of the high caffeine content triggering your body's fight-or-flight response by releasing adrenaline.

While ingredients like taurine and B vitamins are generally safe on their own, their high concentration combined with large amounts of caffeine and sugar can be problematic, and their long-term effects in these blends are not fully understood.

If you experience symptoms like a racing heart, chest pain, or severe anxiety, you should stop drinking the energy drinks immediately and seek medical attention. For milder symptoms, gradually reducing intake is recommended.

For sustained, healthier energy, consider alternatives like adequate sleep, hydration with water, balanced nutrition, and regular exercise.