Supplement
Beetroot / Dietary Nitrate
Clinic blood pressure in hypertension, where trials disagree and the pooled effect does not appear on 24-hour or home readings; smaller or absent in people already on antihypertensive treatment.
Grade C: human trials exist, but they are small, mixed or not yet repeated. This is not a finding that it does not work. How to read a grade →
Beetroot juice is rich in nitrate, which the body turns into a gas that relaxes blood vessels. In people with high blood pressure, studies disagree. The largest study found no change. Where pressure fell, it showed up at the doctor's office but not on readings taken over 24 hours or at home. The effect was smaller or absent in people already on blood pressure pills.
A letter describes the human evidence, not the product, the manufacturer, or the ingredient's worth.
See the full evidence record →Dietary Nitrate · Nitric Oxide · Blood Pressure
Clinic blood pressure in hypertension, where trials disagree; the effect does not appear on 24-hour or home readings.
Why this gradeGrade C, small or unreplicated trials. The reasoning, and what the grade does not cover.
Grade C. Independent trials in hypertensive adults disagree: some show sustained falls in blood pressure, while the largest trial and several others were null, and the pooled effect appears on clinic readings but not on 24-hour or home readings. Blood pressure is a surrogate. Moved from B in October 2026 by editor adjudication.
WHAT THIS GRADE DOES NOT COVERexercise performance, which is not graded on this record; people with normal blood pressure; and cardiovascular events, which no trial has measured.
A grade describes the human evidence for a named use. It is not advice, and it is not a judgment on any individual prescription. How the letters are decided →
Who responds: this record's trial reading reports no subgroup that identifies who responds.
How this letter has changed · latest: October 2026 · Corrected
Two products sold at a longevity conference sit near graded records without being the graded form. Lozenges combining nitrite with plant nitrate now appear on the beetroot record as a separate form, with their three trials (Zand et al., Nutr Res, 2011; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 21530799; Houston et al., J Clin Hypertens, 2014; PMID 24962851; Bryan et al., Am J Med, 2023; PMID 37356641), not counted in the beetroot letter; the only trial on a clinical outcome was null. Glutathione now states that its grade is for the oral form: a transdermal form did not raise plasma reduced glutathione in the one trial comparing routes (Kern et al., Med Sci Monit, 2011; PMID 22129897). Letters unchanged.PMID 21530799 PMID 24962851 PMID 37356641 PMID 22129897
The best-use line claimed vascular and exercise support that no cited trial measured; exercise is now stated as not graded. Siervo 2013 (PMID 23596162) pooled trials of 2 hours to 15 days and is described as acute evidence. The null trials the record left out are cited: Sundqvist 2020 (PMID 32091599), Bondonno 2015 (PMID 26135348), Fejes 2024 (PMID 38546454), and the record now says the effect is smaller or absent in people already on antihypertensive treatment. Kerley 2018 (PMID 29553033), an independent positive replication on 24-hour pressure, is added. Letter unchanged.PMID 23596162 PMID 32091599 PMID 26135348 PMID 38546454 PMID 29553033
Beetroot held a B on one positive trial in hypertensive adults (Kapil et al., Hypertension 2015; PMID 25421976) and an early meta-analysis A study that pools the numbers from several trials into one combined estimate. of mostly acute trials. The largest trial (Sundqvist et al., Am J Clin Nutr 2020; PMID 32091599; 231 adults) was null on 24-hour blood pressure, and pooled analyses find the effect only on clinic readings (Ashor et al., J Hypertens 2017; PMID 28319596; Gronroos et al., Nutr Metab Cardiovasc Dis 2024; PMID 39069465). Mixed: C. Editor adjudication, October 2026.PMID 25421976 PMID 32091599 PMID 28319596 PMID 39069465
Every change to a letter on this site is dated and published. The full evidence log →
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EBL earns no commission on any supplement it grades. A purchase made through the dispensary link below pays EBL nothing, the practitioner discount goes to you in full. The dispensary is Fullscript, a practitioner dispensary, and many of the professional-grade brands in it are sold mainly through practitioners rather than in health food stores. Grades are assigned by published rubric before any commercial relationship exists and are never influenced by one. Full disclosure.
The blood-pressure effect depends entirely on nitrate content. Many commercial beetroot products are nitrate-depleted during processing and do nothing. The trials used nitrate-standardized juice or powder delivering roughly 300–600 mg (about 5–8 mmol) of nitrate per dose. The trials dosed nitrate, not beetroot, and labels often state only beetroot content. Antibacterial mouthwash kills the oral bacteria that convert nitrate to nitric oxide, which blunts the effect.
~300-600 mg dietary nitrate/day (roughly 70-140mL concentrated beetroot juice, or a nitrate-standardized product), taken consistently
The blood-pressure effect was sustained with consistent once-daily intake. For an acute exercise or vascular effect, plasma nitrite peaks about 2–3 hours after a dose, so time it in that window before activity.
In the cited blood pressure trial, the daily 250 mL juice was taken at the same time each morning (PMID 25421976).
Checked against the full published report. What the cited trials did, not a schedule. Every supplement, by trial timing →
Anyone whose blood pressure is already being driven low by treatment. Kidney stones, on the oxalate content. Beeturia, the harmless red urine, is not a reason to stop.
Nitrates and PDE5 inhibitors such as sildenafil: the pathway is the same one, so the effect is additive and the failure mode is hypotension. Antihypertensives, the same way. Antiseptic mouthwash is the interaction nobody expects: oral bacteria are required to reduce dietary nitrate to nitrite, and chlorhexidine mouthwash abolishes both the plasma nitrite rise and the blood-pressure effect. Nitrate-depleted beetroot products do not work for the same underlying reason.
Antiseptic mouthwash abolishes the beetroot effect. Oral bacteria are required to reduce dietary nitrate to nitrite. An antibacterial mouthwash markedly attenuates the plasma nitrite rise and abolishes the blood-pressure lowering effect of dietary nitrate. Govoni et al. (Nitric Oxide, 2008; PMID 18793740): the increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash. Petersson et al. (Free Radical Biology and Medicine, 2009; PMID 19439233): gastroprotective and blood pressure lowering effects of dietary nitrate are abolished by an antiseptic mouthwash.
Home blood-pressure monitoring is the direct readout, measure at the same time daily and watch the two-to-four-week trend in systolic pressure. Exercise-performance changes (time to exhaustion, perceived exertion) are a secondary, more variable signal.
Primary evidenceEleven papers, each linked to its PubMed record.
Kapil et al. (Hypertension, 2015; PMID 25421976): 68 adults with hypertension, half untreated, 4 weeks of nitrate-rich beetroot juice; clinic, ambulatory and home blood pressure fell versus nitrate-free juice; funded by the Medical Research Council and the British Heart Foundation (the review notes the senior author directs a company holding patents on medical uses of inorganic nitrate, which the indexed record does not state). Kerley et al. (Br J Nutr, 2018; PMID 29553033): 20 adults with treated but uncontrolled hypertension, 7 days, 24-hour systolic pressure down 8 mmHg, an independent positive replication. Null: Sundqvist et al. (Am J Clin Nutr, 2020; PMID 32091599), the largest trial, 231 adults with elevated pressure, 300 mg nitrate daily for 5 weeks, no effect on 24-hour systolic pressure; Bondonno et al. (Am J Clin Nutr, 2015; PMID 26135348), 27 treated hypertensives, 1 week, no effect on home or ambulatory pressure despite plasma nitrite up threefold; Fejes et al. (Food Funct, 2024; PMID 38546454), 15 older treated hypertensives, 4 weeks, no effect on vascular function or any blood pressure measure. Pooled: Siervo et al. (J Nutr, 2013; PMID 23596162), 16 crossover A trial design in which each participant receives both the treatment and the comparison, one after the other, and serves as their own control. trials lasting 2 hours to 15 days, mostly healthy volunteers, systolic pressure 4.4 mmHg lower, acute and very short-term evidence; Ashor et al. (J Hypertens, 2017; PMID 28319596), 13 trials of 1 to 6 weeks, the fall present on clinic readings only and absent on 24-hour and home monitoring; Grönroos et al. (Nutr Metab Cardiovasc Dis, 2024; PMID 39069465), 11 trials in hypertension, clinic systolic pressure 5.3 mmHg lower with low certainty, no effect on diastolic or 24-hour pressure. Grade C: independent trials disagree, the effect is confined to clinic readings in the pooled analyses, and several nulls come from people already on antihypertensive treatment. Not counted in this grade, a different form: lozenges combining nitrite with nitrate-rich plant extracts, sold by one maker under two successive brand names. Zand et al. (Nutr Res, 2011; PMID 21530799): randomized trial, 30 days, plasma nitrite and nitrate rose; authors employed by the maker. Houston et al. (J Clin Hypertens, 2014; PMID 24962851): randomized placebo-controlled crossover, 30 adults with untreated hypertension, one lozenge lowered blood pressure at 20 minutes. Bryan et al. (Am J Med, 2023; PMID 37356641): randomized trial, 524 adults with COVID-19, hospitalization, intensive care or death 1.1 against 1.1 percent, stopped for futility; the lead author is the product's developer.
Kapil et al. 2015 (PMID 25421976): RCT Randomized controlled trial: people are assigned to the treatment or a comparison by chance, so the groups differ only in what they received. It is the design that can show cause and effect. in hypertensive adults, dietary nitrate produced sustained blood-pressure reduction over 4 weeks. Meta-analysis 2013 (PMID 23596162): pooled RCTs found roughly a 4–5 mmHg systolic reduction with inorganic nitrate or beetroot juice. The effect depends on nitrate content; many beetroot products are nitrate-depleted.
Independent trials in adults with high blood pressure disagree. Some found sustained falls in blood pressure with nitrate-rich beetroot juice; the largest trial (231 adults, 300 mg nitrate for 5 weeks) and several others found none, and pooled analyses find the effect on clinic readings but not on 24-hour or home readings. Blood pressure is a surrogate, and mixed randomized evidence on a surrogate is Grade C. Moved from B in October 2026.
The trials below gave the supplement in addition to a prescribed drug, with the drug present in both arms. Each result is stated as it was measured. EBL does not translate these findings into anything about a prescription.
Three randomized trials added beetroot juice to existing antihypertensive therapy and they disagree. In 20 people with treated but uncontrolled hypertension over seven days, ambulatory blood pressure fell by about 8 mmHg systolic and 4 mmHg diastolic against placebo An inactive substitute made to look like the real treatment, so participants cannot tell which one they received.. A one-week trial in treated hypertensive individuals found no effect and concluded that raising dietary nitrate may not be effective in this group. A four-week trial in older adults with hypertension found nitrate metabolism changed while vascular function and blood pressure did not. The positive trial is the smallest and the shortest of the three.
Background therapy. Prescribed antihypertensive therapy was continued unchanged in all arms of all three trials; nitrate-rich or nitrate-depleted beetroot juice was added.
Kerley et al. (The British Journal of Nutrition, 2018; PMID 29553033): 7-day double-blind randomized placebo-controlled crossover trial in treated, uncontrolled hypertension. Bondonno et al. (The American Journal of Clinical Nutrition, 2015; PMID 26135348): randomized controlled trial People are assigned to the treatment or a comparison by chance, so the groups differ only in what they received. It is the design that can show cause and effect. finding no blood pressure effect in treated hypertensive individuals. Fejes et al. (Food & Function, 2024; PMID 38546454): 4-week trial in older adults with hypertension finding nitrate metabolism changed while vascular function and blood pressure did not.
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(beetroot[tiab] OR "inorganic nitrate"[tiab] OR "dietary nitrate"[tiab]) AND "blood pressure"[tiab] AND hypertens*[tiab] AND (randomized controlled trial[pt] OR meta-analysis[pt])Grades move when new trials publish. A free monthly email lists every grade EBL moved, with the reason and the trial behind it: the sign-up is on the Evidence Log →