Benefits
Nitric oxide production and vasodilation
Nitratene® supplies dietary nitrate. Bacteria in the mouth convert nitrate to nitrite, and nitrite can be converted to nitric oxide in tissue where oxygen is low, such as hard-working muscle. Nitric oxide relaxes blood vessel walls, which is the proposed route to better blood flow and oxygen delivery. This is the accepted biology of dietary nitrate in general. It has not been measured with Nitratene®, and none of the studies cited on this page used the branded ingredient or measured blood flow after taking it.
Exercise capacity: helps in tests to exhaustion, less clear for timed performance
Two pooled analyses of generic dietary nitrate (mostly beetroot juice) in healthy adults are cited here. The first (76 trials from 47 studies) found a trivial, non-significant overall effect on endurance performance, with a small to moderate benefit only in tests run to exhaustion. The second (73 studies, 1,061 people) found about 4.6 watts more power and 25 more seconds to exhaustion, but no significant change in time-trial results. Neither tested Nitratene®.
Blood pressure: studied in people already diagnosed with high blood pressure
The blood pressure research cited here was done in people already diagnosed with high blood pressure and under medical care, not in healthy shoppers. In one trial, 68 adults with hypertension (34 not yet on medication, 34 already taking blood pressure drugs) drank 250 mL of beetroot juice daily for 4 weeks; clinic readings fell by about 7.7/2.4 mmHg and 24-hour readings by about 7.7/5.2 mmHg. Two points matter for a consumer: that was a food-sized glass of juice, not a capsule of branded extract, and no study has shown Nitratene® to be equivalent to it. High blood pressure is a medical condition to manage with your doctor, and no supplement is a treatment for it.
Mechanism of action
Enterosalivary nitrate-nitrite-NO cycle
Dietary nitrate, including beet root nitrate such as Nitratene®, is absorbed from the small intestine, and about a quarter of it is then secreted into saliva by the salivary glands. This pathway comes from general research on dietary nitrate and has not been measured with this branded ingredient. Oral bacteria, mostly Veillonella and Actinomyces species on the back of the tongue, reduce salivary nitrate to nitrite with bacterial nitrate reductase enzymes; rinsing with an antibacterial mouthwash before a nitrate dose abolished this conversion in saliva and markedly blunted the rise in blood nitrite. Swallowed nitrite is absorbed and carried to tissues where low oxygen, as in exercising muscle, favors its reduction to NO by deoxyhemoglobin, xanthine oxidoreductase and other reductases. In one study in healthy volunteers, blood pressure fell most about 3 hours after 500 mL of beetroot juice, and the fall correlated with the peak rise in blood nitrite.
Clinical trials
Systematic review and meta-analysis of randomized controlled trials of generic dietary nitrate, mostly beetroot juice, and endurance exercise performance. McMahon NF, Leveritt MD, Pavey TG. Sports Med 2017 (PMID 27600147).
76 trials pooled from 47 studies in healthy adults. No participant took Nitratene®.
The overall effect of dietary nitrate on endurance performance was trivial and non-significant (effect size -0.10). A small to moderate benefit appeared only in time-to-exhaustion tests (effect size 0.33), and the authors judged nitrate less likely to help time-trial performance. A 2021 meta-analysis (Gao, 73 studies) was more positive for power, time to exhaustion and distance, but found no significant time-trial difference. Neither tested Nitratene®.