Nitric oxide helps blood vessels relax and plays a role in blood flow. Supplements marketed as “nitric oxide boosters” often contain beetroot or nitrate sources, L-arginine, L-citrulline, or combinations of several ingredients. The evidence is different for each ingredient, and marketing claims often go beyond what research can support.
Beetroot and Nitrate
Beetroot and beet juice are rich in nitrate, which the body can convert into nitric oxide. NIH research summaries suggest beetroot juice may modestly improve endurance performance in some recreationally active people, although results are not consistent in every study.
Evidence from beetroot juice does not automatically prove that every powdered or multi-ingredient “nitric oxide booster” provides the same benefit.
L-Arginine
L-arginine is involved in nitric oxide production, but NIH notes that supplemental arginine has little scientific support for improving strength, endurance, recovery, or exercise performance in most healthy adults. Higher amounts can cause gastrointestinal discomfort and may lower blood pressure.
L-Citrulline
The body can convert citrulline into arginine, but research on citrulline supplements is limited and inconsistent. Some studies report benefits while others do not. Long-term safety at higher supplemental amounts is not well established.
Do Nitric Oxide Supplements Improve Heart Health?
Improving nitric oxide biology is not the same as proving that a supplement prevents heart disease or treats a circulation disorder. Claims that a proprietary blend “supports the heart,” “boosts immunity,” or guarantees better circulation should be treated cautiously unless the finished product has good-quality clinical evidence.
Safety and Interactions
Multi-ingredient products can be harder to evaluate because the exact combination may not have been studied. Our evidence-based guide to pre-workout supplements explains the same problem with mixed stimulant and performance formulas. People who take prescription medicines or have ongoing medical conditions should ask a healthcare professional before using concentrated performance supplements.
How to Evaluate a Product
- Check the exact ingredient amounts rather than relying on a proprietary blend.
- Look for evidence on the finished product, not just one ingredient.
- Avoid claims promising dramatic energy, recovery, cardiovascular, or “anti-inflammatory” effects without strong evidence.
- Do not assume “natural” means safer or more effective.
Bottom Line
Beetroot nitrate has some evidence for exercise endurance, while arginine and citrulline have weaker or inconsistent support for performance. A “nitric oxide booster” should not be treated as a proven heart-health treatment simply because it contains these ingredients.
Reliable Source
Last reviewed for medical accuracy: September 2026.