Dietary nitrate is the inorganic nitrate (NO₃⁻) found naturally in beetroot, leafy greens such as spinach and rocket, and celery. Concentrated beetroot juice is the most common way it is studied and sold to athletes. Once swallowed, nitrate is turned into nitrite and then into nitric oxide (NO), a signaling molecule that widens blood vessels and affects how efficiently muscles use oxygen.

The most important fact is that nitrate is one of only a handful of supplements the International Olympic Committee (IOC) rated as having good evidence for a performance benefit, alongside caffeine, creatine and sodium bicarbonate (Maughan et al., Br J Sports Med 2018). The benefit is small, though, and it is hardest to see in highly trained endurance athletes (Senefeld et al., Med Sci Sports Exerc 2020). Nitrate also lowers blood pressure, an effect that depends on bacteria living on the tongue.

This page summarizes what the clinical trials, meta-analyses and food-safety regulators report. It is for education only and is not medical advice.

Property	Detail
Class	Dietary inorganic nitrate (NO₃⁻); a food constituent, not a drug
Main sources	Beetroot, lettuce, spinach, rocket, celery, cress: typically over 250 mg (over 4 mmol) nitrate per 100 g fresh weight
Forms studied	Beetroot juice (often concentrated “shots”), nitrate-depleted beetroot juice as placebo, sodium nitrate
Route	Oral
Studied doses	5–9 mmol (310–560 mg) nitrate as an acute dose; ≈6.4 mmol/day in a 4-week blood-pressure trial
Timing	Plasma nitrite peaks ≈2–3 h after a dose; trials test exercise 2–3 h after ingestion
Half-life	Nitrate ≈6 h after oral dosing; nitrite ≈30 min (estimates cited in Kapil et al. 2015)
Key mechanism	Oral bacteria reduce nitrate to nitrite, which the body converts to nitric oxide, especially when oxygen is low
Food-safety limit	Acceptable daily intake (ADI) 3.7 mg/kg body weight per day (SCF 1997, JECFA 2002; kept by EFSA in 2017)
WADA status	Not on the WADA 2026 Prohibited List

What it is

Nitric oxide is made in the body in two ways. The classic route uses the amino acid L-arginine and oxygen, in a reaction run by nitric oxide synthase (NOS) enzymes. NO is then oxidized to nitrite and nitrate. For decades these were treated as inert waste products (Jones, Sports Med 2014). Supplements such as citrulline malate aim to boost this arginine-dependent route.

The second route runs the other way: nitrate → nitrite → NO. In 2004, Lundberg and Govoni gave volunteers sodium nitrate (10 mg/kg) and saw a 4-fold rise in plasma nitrite. When the volunteers avoided swallowing their saliva after the dose, the rise in plasma nitrite did not happen, which showed that the nitrite came from the mouth (Lundberg & Govoni, Free Radic Biol Med 2004). This nitrate–nitrite–NO pathway does not depend on NOS, and it is the one beetroot juice feeds.

Pathway	Starting material	Key step	Oxygen needed
NOS pathway	L-arginine (from diet, or made from citrulline)	NOS enzymes make NO from arginine and oxygen	Yes
Nitrate–nitrite–NO pathway	Dietary nitrate (beetroot, leafy greens)	Oral bacteria reduce nitrate to nitrite; nitrite is reduced to NO	No; NO formation from nitrite is favored when oxygen and pH are low

Beetroot juice also contains other compounds, including polyphenols. The development of a nitrate-depleted beetroot juice as a placebo allowed researchers to show that nitrate itself drives the effects (Jones, Sports Med 2014).

How it works in the body

The enterosalivary circulation

The route from beetroot to nitric oxide involves a loop through the mouth (Jones, Sports Med 2014):

Nitrate is absorbed from the gut and circulates in the blood.
About 25% is taken up by the salivary glands and concentrated in saliva.
Facultative anaerobic bacteria in the crypts on the surface of the tongue reduce nitrate to nitrite.
Swallowed nitrite is partly converted to NO in the acidic stomach; the rest is absorbed and raises plasma nitrite.
In blood and tissues, deoxyhemoglobin and other enzymes and proteins reduce nitrite to NO. This happens more readily when oxygen is low (hypoxia) and pH is low, conditions that can occur in working muscle.

Because the body reduces nitrate to NO step by step, nitrate behaves like a “pro-drug” for plasma nitrite (Kapil et al., Hypertension 2015).

Timing and dose-response

The key dose-finding study gave 10 healthy men 70, 140 or 280 mL of concentrated beetroot juice, containing 4.2, 8.4 and 16.8 mmol nitrate (Wylie et al., J Appl Physiol 2013):

Dose (nitrate)	O₂ cost of moderate exercise vs placebo	Time to task failure in severe exercise vs placebo
4.2 mmol (70 mL)	No change	No change
8.4 mmol (140 mL)	−1.7% (P = 0.06)	+14% (P under 0.05)
16.8 mmol (280 mL)	−3.0% (P under 0.05)	+12% (P under 0.05)

Plasma nitrite rose in a dose-dependent way and peaked about 2–3 hours after the drink. Exercise tests were run 2.5 h after ingestion. Doubling the dose from 8.4 to 16.8 mmol gave no further gain in exercise tolerance.

Effects on exercise physiology

In a crossover trial, eight men drank 500 mL/day of beetroot juice (≈11.2 mmol/L nitrate) or a near-nitrate-free blackcurrant cordial for 6 days (Bailey et al., J Appl Physiol 2009). With beetroot juice:

plasma nitrite was higher (273 vs 140 nM);
systolic blood pressure was lower (124 vs 132 mmHg);
the rise in oxygen uptake at the start of moderate exercise was 19% smaller;
time to exhaustion in severe exercise was longer (675 vs 583 s).

The IOC consensus lists the proposed mechanisms: better function of type II (fast-twitch) muscle fibers, a lower ATP cost of muscle force production, more efficient mitochondrial respiration, and increased muscle blood flow (Maughan et al., Br J Sports Med 2018).

Regulatory status

Nitrate is a normal part of the diet. Average intake from regular food, mostly vegetables, is about 1.5–2 mmol per day (Kapil et al., Hypertension 2015). Nitrate and nitrite are also added to cured and processed meats to fix color and delay spoilage (Jones, Sports Med 2014); in the EU, sodium nitrate (E 251) and potassium nitrate (E 252) are regulated as food additives.

In 2017 the European Food Safety Authority (EFSA) re-evaluated these additives (EFSA ANS Panel, EFSA J 2017). Key points:

The ADI for nitrate of 3.7 mg/kg body weight per day was set by the EU Scientific Committee on Food (1997) and JECFA (2002). EFSA found insufficient evidence to withdraw it, despite uncertainty in how it was derived.
The ADI is based on concern about methemoglobin, a form of hemoglobin that cannot carry oxygen, formed from nitrite made out of salivary nitrate.
Sodium and potassium nitrate showed no genotoxic potential, and carcinogenicity studies in mice and rats were negative.
When all dietary sources are counted (additives, natural content and contamination), the ADI is exceeded at mean and high exposure in all age groups.

Kapil and colleagues note that the ADI works out to about 4.2 mmol per day for a 70 kg person (Kapil et al., Hypertension 2015). This is below the 5–9 mmol doses used in most performance studies. Jones points out that 5–9 mmol can still be reached through a normal vegetable-rich diet (Jones, Sports Med 2014).

Nitrate is not on the WADA 2026 Prohibited List.

What the research shows

The IOC 2018 consensus

The IOC consensus on dietary supplements put nitrate among the few supplements with enough support to suggest that marginal performance gains may be possible (Maughan et al., Br J Sports Med 2018). It summarized the evidence as follows:

Topic	IOC 2018 summary
Acute dose	Benefits generally seen 2–3 h after a bolus of 5–9 mmol (310–560 mg)
Longer use	Intake over more than 3 days also appears beneficial, and may help highly trained athletes, in whom gains are harder to get
Time to exhaustion	Improved by 4–25%
Time trials under 40 min	Improved by 1–3%
Team-sport intermittent exercise of 12–40 min	Improved by 3–5%
Tasks under 12 min	Evidence equivocal
Upper limit	No greater benefit from 16.8 mmol (1,041 mg) than from 8.4 mmol (521 mg)

Endurance meta-analyses

Later meta-analyses agree that nitrate helps open-ended tests (how long you can keep going) more than time trials (how fast you cover a set distance):

Analysis	Data	Main result
McMahon et al., Sports Med 2017	47 studies, 76 trials	Time to exhaustion: ES 0.33 (95% CI 0.15–0.50). Time trials: no significant effect. Graded exercise tests: ES 0.25 (95% CI −0.06 to 0.56), not significant
Senefeld et al., Med Sci Sports Exerc 2020	80 crossover studies in young healthy adults	Overall d = 0.174 (95% CI 0.120–0.229). No effect in well-trained athletes with VO₂max ≥65 mL/kg/min (d = 0.021, 26 studies) or in women-only studies (d = 0.116, 6 studies)
Poon et al., Sports Med 2025 (umbrella review)	20 meta-analyses, 180 primary studies, 2,672 participants	Time to exhaustion: SMD 0.33 (95% CI 0.19–0.47; 41 studies). Time trials: SMD −0.03 (95% CI −0.14 to 0.09; 42 studies). VO₂max: SMD −0.10, not significant

The 2025 umbrella review found larger gains in time to exhaustion with at least 6 mmol (372 mg) per day and with supplementation for more than 3 days. Its authors rated the methodological quality of most included reviews as low to critically low (Poon et al., Sports Med 2025).

Senefeld and colleagues described the overall effect as “objectively small.” They concluded that nitrate has more limited use as an ergogenic aid in people with excellent aerobic fitness, and that women are understudied (Senefeld et al., Med Sci Sports Exerc 2020).

High-intensity and intermittent exercise

Results for sprints and short, hard efforts are mixed:

Analysis	Data	Improved	Not improved
Alsharif et al., Antioxidants 2023	23 studies in meta-analysis	Faster time to peak power (SMD 0.75), mean power output (SMD 0.20), Yo-Yo intermittent recovery level 1 distance (SMD 0.17)	Peak power output
Poon et al., Sports Med 2025	Pooled primary studies	Muscular endurance (SMD 0.48; 95% CI 0.23–0.74; 22 studies), peak power output (SMD 0.25), faster time to peak power (SMD −0.76)	Muscular strength (SMD 0.05; 27 studies)
Eroglu et al., Nutrients 2026	23 trials, 401 participants (beetroot juice only)	Faster time to peak power in Wingate tests (SMD −0.92, 4 studies), handgrip strength (SMD 0.40)	Countermovement jump, peak and mean power, 10 m and 20 m sprints, perceived exertion, lactate

The 2026 meta-analysis rated the certainty of evidence as low for most outcomes and concluded that it does not support routine use of beetroot juice to improve short sprints or repeated-sprint performance (Eroglu et al., Nutrients 2026).

Blood pressure

The blood-pressure effect is the most consistent finding with dietary nitrate.

Acute effect. In healthy volunteers, 500 mL of beetroot juice lowered blood pressure by up to 10.4/8 mmHg about 3 hours later. The drop tracked the peak in plasma nitrite. When the recycling of nitrate through saliva was interrupted, plasma nitrite did not rise and blood pressure did not fall (Webb et al., Hypertension 2008).
Hypertension trial. In a double-blind trial, 68 people with hypertension (half untreated, half on medication) drank 250 mL/day of beetroot juice providing ≈6.4 mmol nitrate, or a nitrate-free placebo juice, for 4 weeks (Kapil et al., Hypertension 2015).

Measurement	Reduction vs placebo (systolic/diastolic, mmHg)
Clinic	7.7/2.4 (95% CI 3.6–11.8/0.0–4.9)
24-hour ambulatory	7.7/5.2 (95% CI 4.1–11.2/2.7–7.7)
Home	8.1/3.8 (95% CI 3.8–12.4/0.7–6.9)

The effect did not fade over 4 weeks. Endothelial function (how well blood vessels widen) improved by about 20%, and arterial stiffness fell.

Meta-analyses show a smaller, less certain effect:

Analysis	Trials	Systolic	Diastolic
Siervo et al., J Nutr 2013: 2 h to 15 days	16 trials, 254 participants	−4.4 mmHg (95% CI −5.9 to −2.8)	−1.1 mmHg (95% CI −2.2 to 0.1), not significant
Ashor et al., J Hypertens 2017: 1–6 weeks	13 trials, 325 participants	−4.1 mmHg (95% CI −6.1 to −2.2)	−2.0 mmHg (95% CI −3.0 to −0.9)

In the 2017 analysis, the effect was significant only for blood pressure measured in the clinic; 24-hour ambulatory and home readings showed no significant change. The 2013 analysis found that higher daily nitrate doses were linked to larger falls in systolic pressure.

The mouthwash finding

Because oral bacteria do the first conversion step, killing them with antiseptic mouthwash blunts the nitrate pathway:

Plasma nitrite. In 7 healthy volunteers, rinsing with chlorhexidine mouthwash before a sodium nitrate dose (10 mg/kg) did not stop nitrate from building up in saliva, but it abolished its conversion to nitrite in saliva and markedly blunted the rise in plasma nitrite (Govoni et al., Nitric Oxide 2008).
Resting blood pressure. In 19 healthy volunteers, 7 days of chlorhexidine mouthwash cut oral nitrite production by 90% and plasma nitrite by 25%, and raised systolic and diastolic blood pressure by 2–3.5 mmHg. The effect appeared within 1 day (Kapil et al., Free Radic Biol Med 2013). The authors concluded that oral bacteria, by recycling the body’s own nitrate, help set normal blood pressure.
Type of mouthwash. After an 8.4 mmol beetroot juice dose in 12 men, antibacterial (Cepacol) and chlorhexidine mouthwashes lowered plasma and salivary nitrite more than an antiseptic (Listerine) mouthwash or water (Woessner et al., Nitric Oxide 2016).
After exercise. In 23 healthy people, antibacterial mouthwash used after a moderate treadmill session blunted the usual post-exercise drop in systolic blood pressure by 61% at 1 hour and fully at 2 hours (Clarke et al., Free Radic Biol Med 2019).

The IOC consensus also lists the microbiome as one reason responses to nitrate vary between people (Maughan et al., Br J Sports Med 2018).

Side effects and risks

Beeturia and stool discoloration

Red or pink urine after eating beetroot, called beeturia, is reported in 10–14% of people and is more common with iron deficiency and malabsorption (Watts et al., Pharmacogenetics 1993). It comes from betacyanin pigments, not from nitrate. In the 4-week hypertension trial, beeturia and red stool were the common, expected findings; no serious adverse events occurred (Kapil et al., Hypertension 2015).

Stomach upset

The IOC consensus notes few side effects overall, with possible gastrointestinal upset in susceptible athletes (Maughan et al., Br J Sports Med 2018).

Methemoglobin and nitrosamines

The theoretical concerns about nitrate are methemoglobinemia and the formation of N-nitroso compounds, some of which can cause cancer.

In the 4-week hypertension trial, methemoglobin levels did not change, and blood chemistry and blood counts were unchanged (Kapil et al., Hypertension 2015).
EFSA judged that even with the highest nitrate-to-nitrite conversion estimate, methemoglobin from dietary nitrate would not be clinically significant, and estimated N-nitroso compound formation would be of low concern (EFSA ANS Panel, EFSA J 2017).
Jones notes that nitrate itself is not toxic because it converts to nitrite slowly, but that nitrite salts used accidentally or without control can be toxic. Antioxidants in vegetables inhibit nitrosation, which is one reason expert opinion favors vegetable sources over nitrate or nitrite salts (Jones, Sports Med 2014).
Long-term safety of high-dose beetroot juice has not been tested; the trials last days to weeks.

Kidney stones

Beetroot and spinach are high in oxalate as well as nitrate. The authors of the hypertension trial noted that people prone to oxalate kidney stones may need to avoid these vegetables (Kapil et al., Hypertension 2015).

Blood pressure medications

Half of the 68 patients in the 4-week hypertension trial were already taking blood-pressure medication, and the intervention was well tolerated (Kapil et al., Hypertension 2015). The trial was not designed to study drug interactions, so how nitrate adds to specific blood-pressure drugs is not well defined.

Key takeaways

One of few supplements with good evidence. The IOC 2018 consensus lists nitrate with caffeine, creatine and sodium bicarbonate as supplements that may give marginal performance gains.
Small, task-dependent benefit. Meta-analyses show improved time to exhaustion (SMD ≈0.33) and muscular endurance, but no clear benefit for time trials, VO₂max or strength.
Less useful for elite endurance athletes. No effect was found in well-trained athletes with VO₂max ≥65 mL/kg/min, and women are understudied.
Studied doses are 5–9 mmol, 2–3 hours before exercise. Going from 8.4 to 16.8 mmol gave no extra benefit; longer use (over 3 days) and at least 6 mmol/day gave larger gains in endurance tests.
Blood pressure falls, depending on oral bacteria. Systolic pressure drops by about 4 mmHg on average in meta-analyses, and antibacterial mouthwash blunts the pathway.
Generally well tolerated. Red urine and stool are expected pigment effects. Performance-study doses exceed the food ADI for a 70 kg adult, and long-term safety has not been studied.

Sources

Maughan RJ, Burke LM, Dvorak J, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018;52(7):439–455. PubMed; PMC.
Jones AM. Dietary nitrate supplementation and exercise performance. Sports Med. 2014;44(Suppl 1):S35–S45. PubMed; PMC.
Lundberg JO, Govoni M. Inorganic nitrate is a possible source for systemic generation of nitric oxide. Free Radic Biol Med. 2004;37(3):395–400. PubMed.
Wylie LJ, Kelly J, Bailey SJ, et al. Beetroot juice and exercise: pharmacodynamic and dose-response relationships. J Appl Physiol (1985). 2013;115(3):325–336. PubMed.
Bailey SJ, Winyard P, Vanhatalo A, et al. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. J Appl Physiol (1985). 2009;107(4):1144–1155. PubMed.
McMahon NF, Leveritt MD, Pavey TG. The effect of dietary nitrate supplementation on endurance exercise performance in healthy adults: a systematic review and meta-analysis. Sports Med. 2017;47(4):735–756. PubMed.
Senefeld JW, Wiggins CC, Regimbal RJ, et al. Ergogenic effect of nitrate supplementation: a systematic review and meta-analysis. Med Sci Sports Exerc. 2020;52(10):2250–2261. PubMed; PMC.
Poon ET, Iu JC, Sum WM, et al. Dietary nitrate supplementation and exercise performance: an umbrella review of 20 published systematic reviews with meta-analyses. Sports Med. 2025;55(5):1213–1231. PubMed; PMC.
Alsharif NS, Clifford T, Alhebshi A, et al. Effects of dietary nitrate supplementation on performance during single and repeated bouts of short-duration high-intensity exercise: a systematic review and meta-analysis of randomised controlled trials. Antioxidants (Basel). 2023;12(6):1194. PubMed.
Eroglu MN, Pancar S, López-Torres O, Fernández-Elías VE. The effects of beetroot juice supplementation on performance and fatigue during single and repeated sprints: a systematic review and meta-analysis. Nutrients. 2026;18(15):2513. PubMed.
Webb AJ, Patel N, Loukogeorgakis S, et al. Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite. Hypertension. 2008;51(3):784–790. PubMed.
Kapil V, Khambata RS, Robertson A, et al. Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study. Hypertension. 2015;65(2):320–327. PubMed; PMC.
Siervo M, Lara J, Ogbonmwan I, Mathers JC. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis. J Nutr. 2013;143(6):818–826. PubMed.
Ashor AW, Lara J, Siervo M. Medium-term effects of dietary nitrate supplementation on systolic and diastolic blood pressure in adults: a systematic review and meta-analysis. J Hypertens. 2017;35(7):1353–1359. PubMed.
Govoni M, Jansson EA, Weitzberg E, Lundberg JO. The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash. Nitric Oxide. 2008;19(4):333–337. PubMed.
Kapil V, Haydar SM, Pearl V, et al. Physiological role for nitrate-reducing oral bacteria in blood pressure control. Free Radic Biol Med. 2013;55:93–100. PubMed.
Woessner M, Smoliga JM, Tarzia B, et al. A stepwise reduction in plasma and salivary nitrite with increasing strengths of mouthwash following a dietary nitrate load. Nitric Oxide. 2016;54:1–7. PubMed.
Clarke C, Kiernan M, Willis JR, et al. Post-exercise hypotension and skeletal muscle oxygenation is regulated by nitrate-reducing activity of oral bacteria. Free Radic Biol Med. 2019;143:252–259. PubMed.
EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Mortensen A, Aguilar F, et al. Re-evaluation of sodium nitrate (E 251) and potassium nitrate (E 252) as food additives. EFSA J. 2017;15(6):e04787. PubMed.
Watts AR, Lennard MS, Mason SL, et al. Beeturia and the biological fate of beetroot pigments. Pharmacogenetics. 1993;3(6):302–311. PubMed.
World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. WADA 2026 Prohibited List.

Beetroot (Dietary Nitrate)