CircO2 Review
A beetroot-and-citrulline lozenge built to raise nitric oxide for circulation.
Bottom line: CircO2 is one of the more credible products in this roundup. The nitric-oxide rationale is sound, the ingredients are appropriate, and the included test strips give you a rare way to verify you're actually responding. Marketing aside, it's a well-constructed circulatory-support option backed by a strong guarantee — our top pick in the heart category.
What is CircO2?
CircO2 is a nitric-oxide (NO) support supplement from Advanced Bionutritionals, delivered as a fast-dissolving lozenge rather than a capsule. Nitric oxide is a signaling molecule that helps blood vessels relax and widen, so it's genuinely relevant to circulation, blood pressure, energy, and stamina — all of which decline with age.
What sets CircO2 apart is that it includes NO test strips so you can actually see whether your levels are responding. That measurable feedback loop is unusual and, from a trust standpoint, welcome.
How it works
The formula pairs dietary nitrate sources (beetroot) with L-citrulline, an amino acid the body converts to arginine and then to nitric oxide, plus cofactors like vitamin C and B12. Delivering it as a lozenge that dissolves in the mouth is intended to kick off nitric-oxide production via the oral route, complementing the pathway that runs through the gut.
Key ingredients
Ingredient descriptions reflect general research and traditional use. Exact per-serving amounts are set by the manufacturer; check the current label for the definitive Supplement Facts panel.
Potential benefits
- Supports healthy nitric-oxide levels and blood flow
- May help energy, stamina, and exercise tolerance
- Includes test strips to verify your NO response
- Convenient lozenge format
Pros & cons
Pros
- Ingredients with real circulatory rationale
- Included test strips add measurable feedback
- Physician-formulated, transparent brand
- 90-day 'down to the last lozenge' guarantee
Cons
- Lozenge taste isn't for everyone
- Results depend on diet and baseline NO status
- Priced above basic beetroot powders
- Marketing leans on dramatic 'superhuman' framing
Who it's for
Adults over 45 who want circulatory, energy, and stamina support, active people looking to improve exercise tolerance, and anyone who likes the idea of measuring results with the included strips. Anyone on blood-pressure or nitrate medication should check with their doctor first.
Pricing & guarantee
Guarantee: 90-day money-back guarantee. Pricing and offers are set by the seller and can change — confirm the current price on the official site before ordering.
Frequently asked questions
What does CircO2 actually do?
How do the test strips work?
How quickly might I notice something?
Is it safe with blood-pressure medication?
Our verdict
CircO2 is one of the more credible products in this roundup. The nitric-oxide rationale is sound, the ingredients are appropriate, and the included test strips give you a rare way to verify you're actually responding. Marketing aside, it's a well-constructed circulatory-support option backed by a strong guarantee — our top pick in the heart category.
Ready to try CircO2?
Check current pricing, bundle discounts, and the money-back guarantee on the official website.
Visit Official SiteThese statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This review reflects our independent editorial opinion and general research; individual results vary. Consult your healthcare provider before use. Reviews-Supplements may earn a commission if you purchase through the link above, at no additional cost to you.