Vital
Our verdict
A clever lozenge format that uses the mouth's own nitrate-to-nitric-oxide pathway, with a high B12 dose as a bonus. Worth trying for stamina and circulation support, but not if you take nitrates, ED drugs or have low blood pressure.
from $41.50$49.95per bottle in the 6-pack
Check today's price on the official site →Official store · 90-day money-back guarantee
What is CircO2 Nitric Oxide Lozenges?
CircO2 is Advanced Bionutritionals' nitric oxide supplement. Instead of a capsule you swallow, it is a lozenge that dissolves on your tongue. The reasoning is that the first step in turning dietary nitrate into nitric oxide happens in the mouth, thanks to bacteria on the tongue. If you are new to the topic, start with our guide to nitric oxide after 60.
| Form | 30 fast-dissolving lozenges, 1 to 2 a day |
|---|---|
| Main ingredients | 420 mg nitric oxide blend (beetroot, hawthorn, L-citrulline, sodium nitrite), 1,000 mcg B12, 100 mg vitamin C |
| Formulated by | Dr. Greg Eckel, ND |
| Store rating | 3.9 out of 5 from 1,618 customer reviews on the official site |
| Guarantee | 90 days |
Ingredients and doses
| Ingredient | Per daily serving | What the research says |
|---|---|---|
| Beetroot powder | part of 420 mg blend | A natural source of nitrate. Beetroot juice studies show modest improvements in blood pressure and exercise performance in some people. |
| Sodium nitrite | part of blend | A direct precursor of nitric oxide. Lozenges combining nitrite with other ingredients have raised nitric oxide markers in small studies. |
| L-citrulline | part of blend | Converted to arginine and then nitric oxide. Studies typically use 3 to 6 g a day, much more than fits in this blend, so its role here is supporting. |
| Hawthorn berry extract | part of blend | A traditional heart herb with some evidence for supporting healthy circulation. |
| Vitamin B12 (methylcobalamin) | 1,000 mcg | Useful for older adults, who often absorb less B12 from food. |
| Vitamin C | 100 mg | Helps protect nitric oxide from breaking down. |
The 420 mg proprietary blend does not list individual amounts, so the beetroot and citrulline doses are unknown and likely small. Most of the effect probably comes from the nitrite and nitrate.
Does it work? What the research says
The mouth-first approach is grounded in real science: rinsing with antiseptic mouthwash blunts the nitrate-to-nitrite conversion in studies, which shows how important oral bacteria are. Nitrite-based lozenges have raised nitric oxide markers within minutes in small trials, and the company cites a 200% rise in 20 minutes from its own testing.
What that means for how you feel is less certain. Some users report more stamina on walks and warmer hands and feet; others notice little. The sales page links the product to lower blood pressure, better memory and sexual performance. Treat those as possibilities to discuss with your doctor, not promises.
Who it suits, and who should skip it
Good fit
- Active adults over 60 who want to support stamina and circulation
- People who dislike swallowing pills
- Those who want a B12 top-up at the same time
Skip it or ask your doctor first
- Anyone taking nitrates (nitroglycerin, isosorbide) or erectile dysfunction drugs (sildenafil, tadalafil)
- People with low blood pressure or who take several blood pressure drugs, unless their doctor approves
- Pregnant or breastfeeding women
Pros and cons
Pros
- Unique lozenge format that works with the mouth's own chemistry
- Fast acting according to the company's testing
- Generous B12 dose
- Large number of customer reviews
Cons
- Proprietary blend with undisclosed amounts
- Lower average customer rating than most products in the range
- Interaction risk with common heart and ED medicines
Price, guarantee and where to buy
| Package | Per bottle | Total | Shipping |
|---|---|---|---|
| 1 bottle (1 month) | $49.95 | $49.95 | plus shipping |
| 3 bottles (3 months) | $44.95 | $134.85 | Free |
| 6 bottles (6 months) | $41.50 | $249.00 | Free |
Prices listed on the official store on October 26, 2026. They change from time to time, so check the current offer before ordering. Every package is a one-time payment on the order page we checked.
That works out to about $1.38 a day (one lozenge) on the 6-pack. Advanced Bionutritionals offers a 90-day money-back guarantee on every package: you can return the bottles, even empty, within 90 days of purchase for a refund. You pay the return shipping. Buying from the official store is the only way to be sure you get genuine, in-date stock and the guarantee.
How to take it: Let one lozenge dissolve on your tongue, usually in the morning; some people take a second one before exercise. Avoid antiseptic mouthwash right before or after.
Check today's price on the official site →Official store · 90-day money-back guarantee
Keep reading
Nitric oxide after 60
Keeping muscle after 60Frequently asked questions
Is CircO2 safe for seniors?
For most healthy adults it is well tolerated, but it can lower blood pressure. Do not use it with nitrates or erectile dysfunction drugs, and ask your doctor if you take blood pressure medicine.
How fast does CircO2 work?
The company reports nitric oxide levels rising within 20 minutes. Effects on stamina or well-being are best judged over several weeks.
Can CircO2 replace blood pressure medication?
No. Never stop or reduce prescribed medication on your own. If you try CircO2, keep monitoring your blood pressure and share the readings with your doctor.
Why a lozenge instead of a pill?
Bacteria on the tongue convert nitrate into nitrite, the first step toward nitric oxide. A lozenge keeps the ingredients in the mouth longer.