“This supplement works very good. I could feel the results within a couple days.”
Jerome V., Australia
Verified Customer
Verified Customer
★★★★★
Nitric Oxide Levels Jump 200% Higher In Just 20 Minutes
Boosts your energy… sharpens memory… increases stamina...enhances sexual performance…and helps lower blood pressure
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Five stars rating Why You Need Nitric Oxide
Nitric oxide is the “youth molecule” your body uses to keep your blood vessels open, oxygen flowing, and brain firing. It is essential to maintaining vitality and overall health as you age.
But research shows that by age 70 your nitric oxide levels drop by a whopping 75%. By 80, nitric oxide levels are down by 85% — dramatically reducing this critical molecule's function in your body.
This depletion can cause a range of health concerns including:
- Fatigue that leaves you feeling drained and lacking energy
- Blood pressure concerns that stress your cardiovascular system
- Memory lapses, often called “senior moments” affecting mental clarity
- Reduced intimacy, impacting your confidence and relationships
- Joint discomfort that restricts your mobility and enjoyment of life
- Cold hands and feet, signs of poor circulation and circulation imbalance
CircO2 is designed to fix these nitric oxide deficiencies quickly and effectively by boosting its production in your body within 20 minutes, helping restore your youthful energy, circulation, and vitality.
Why Most “Nitric Oxide” Supplements Fail
The most common ways people try to boost their nitric oxide levels don’t work. Here’s why:
- L-arginine supplements: They lose up to 75% potency during digestion and become less effective after age 45.
- Beet juice and leafy greens: Although effective, you'd need to consume 2-3 pounds daily, and the power can vary significantly.
- Standard pills and capsules: They rely on gut absorption, but nitric oxide production starts primarily in the mouth, so gut absorption is less effective.
MIT Breakthrough That Changes Everything
MIT scientists discovered that nitric oxide production starts in your mouth. It’s the bacteria on your tongue that convert nitrates into nitric oxide. That’s the first and most important step in boosting nitric oxide naturally.
That’s why CircO2 comes in fast-dissolving lozenges. You place one on your tongue, and within minutes it kickstarts nitric oxide production through this bacterial conversion process.
In clinical testing, this method raised nitric oxide levels by 200% within just 20 minutes. It also increased blood flow by a staggering 34%, supporting your cardiovascular health and overall vitality.
No pill or capsule can achieve these rapid and effective results because they don't interact with the mouth’s unique nitric oxide production pathway.
Ingredients & Nutrients
3 Energy-Enhancing Nutrients
#1 Beet Root Powder – Olympic-Level Stamina & Power
Rich in natural nitrates, beet root powder dramatically boosts blood vessel dilation to support stamina and endurance at any age.
#2 Hawthorn Berry – The Absorption Booster
This powerful berry supports heart health and enhances nitric oxide absorption so you get the most from every dose of CircO2.
#3 L-Citrulline – Superior to L-Arginine
This ingredient converts more efficiently into nitric oxide precursors, supporting circulation, blood pressure, mental clarity, and sexual performance.
More Nutrients That Multiply the Benefits
Vitamin B12
Supports nerve function and nitric oxide synthesis, helping sustain your body's vitality and energy levels.
Vitamin C
As a potent antioxidant, vitamin C enhances nitric oxide stability and helps maintain healthy endothelial function.
Magnesium
Relaxes blood vessels to improve circulation and supports heart and joint health for better mobility and comfort.
Together, these ingredients create a complete, advanced nitric oxide system that supports your entire body’s vitality, energy, and performance daily.
How CircO2 Will Transform Your Daily Life
- Renewed energy and stamina to power through every day
- Sharper thinking and improved memory recall
- Supports healthier blood pressure and cardiovascular function
- Improved joint mobility and decreased discomfort
- Enhanced intimacy and sexual performance
- Improved quality of sleep leaving you refreshed
- Youthful vitality and overall wellbeing every day
About Dr. Frank Shallenberger
Dr. Frank Shallenberger is the Editor-in-Chief of Second Opinion Newsletter and Second Opinion Health Alert, renowned for his dedication to improving health naturally. He earned his medical degree from the University of Maryland School of Medicine and is board certified by the American Board of Anti-Aging Medicine.
With over 44 years of practicing medicine, Dr. Shallenberger brings a wealth of experience and trusted knowledge to developing advanced health products like CircO2, designed to help people stay active, youthful, and healthy as they age.
Customer Testimonials
“I’m 76 years old my blood pressure went from 140 over 80 to 110 over 68.”
Michael N., WA
Verified Customer
Verified Customer
★★★★★
“Feeling fresh and lively after taking CircO2.”
Rebecca C., Verified Customer
★★★★★
“This product has increased my energy levels greatly.”
Jessica Miller, Verified Purchase
★★★★★
“This really seems to help ease my restless legs.”
Michael Thompson, Verified Purchase
★★★★★
“I feel it is lifting me up some... looking for better days with CircO2.”
Anna L., Verified Customer
★★★★★
Try CircO2 Risk-Free with Our 90-Day Guarantee
Order with confidence knowing that if you are not completely satisfied, you can return CircO2 within 90 days for a full refund—even if the box is empty. This risk-free offer ensures your peace of mind while experiencing the natural benefits of CircO2’s advanced nitric oxide support.
We also recommend ordering at least 3 boxes to enjoy savings and free shipping.
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Frequently Asked Questions
Yes. CircO2 contains ingredients with a long history of safety. Thousands of customers have used it without serious side effects. However, people with low blood pressure should consult their physician before use.
Many people notice effects within a few minutes, while others may take days or weeks. Benefits tend to increase with consistent use, and the product is backed by a 90-day money-back guarantee.
Yes, CircO2 supports endothelial health which tends to decline with age. It helps maintain vascular function and overall health even if current energy and blood pressure are good.
Many users start with twice daily for the first one to two weeks, then reduce to once daily in the morning based on response.
No. CircO2’s lozenges dissolve in the mouth and provide enough time to interact with oral bacteria to produce nitric oxide, so normal oral hygiene is fine.
Yes. Allowing the lozenge to fully dissolve allows maximum interaction with oral bacteria for optimal nitric oxide production and absorption.
CircO2 works by naturally boosting nitric oxide and does not contain stimulants like caffeine, so it provides energy without jitters or crashes.
CircO2 is exclusively available through the official website. This ensures you receive the authentic product with a full 90-day money-back guarantee.
Yes. CircO2 is made with natural, non-GMO, gluten-free ingredients and manufactured under FDA-compliant GMP-certified facilities in the USA.
Absolutely. By increasing nitric oxide and blood flow, CircO2 helps ease joint discomfort and strengthens cardiovascular function for overall wellness.
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What Customers Are Saying
Rated 5 out of 5 stars by thousands of satisfied customers
“More stamina anyone? CircO2 gives me a reservoir of mental energy left at the end of the day that I didn’t have before. Glad I tried this product!”
Jerome V., Australia
Verified Customer
“More energy at gym and home, I bought CircO2 about a month ago and started noticing results by week two.”
Michael N., WA
Verified Customer
“Best Nitric Oxide supplement; I sleep better and feel more motivated throughout the day.”
Gerald W., CA
Verified Customer
“Improved energy and sleep quality. I feel like I’ve found a natural way to support my heart.”
Linda S., TX
Verified Customer
Dr. Frank Shallenberger is compensated by Advanced Bionutritionals for his time and expertise in developing CircO2.
These statements have not been evaluated by the Food & Drug Administration. CircO2 is not intended to diagnose, treat, cure, or prevent any disease.
Discover How CircO2 Supports Your Endothelium & Energy
Watch this informative video to learn about the unique science behind CircO2's nitric oxide boosting formula. Understand how it revitalizes your endothelium to improve circulation, oxygen delivery, energy, joint comfort, mental clarity, and much more. See why CircO2 is the fastest, most effective way to naturally regain youthful vitality.