Beetroot Capsules: How Much Nitrate, Who Should Avoid Them

The beetroot trials used 6 to 8 mmol of nitrate, which is 372 to 496 mg, taken two to three hours before exercise or every day for four weeks; capsules carry a fraction of that, and the figure to look for on a label is milligrams of nitrate, not grams of beetroot.^{1, 2, 5} A typical two-capsule serving declares tens of milligrams of nitrate; some capsules also add potassium, which contributes to the maintenance of normal blood pressure.¹⁴ Ask a pharmacist or GP first if you take blood pressure medicines, have kidney disease, have formed a calcium oxalate kidney stone, or are pregnant or breastfeeding. Vegetables are on the foods high in nitrates page.

Sources checked on 30 October 2026.

How much nitrate is in beetroot capsules?

Read the nitrate milligrams, not the beetroot grams. Capsules are sold by weight of beetroot powder, and nitrate varies from batch to batch of beetroot and its juice, so two products with the same grams of powder can differ.² One millimole of nitrate is 62 mg, so 6 to 8 mmol is 372 to 496 mg, and the 250 ml of nitrate-rich juice that lowered blood pressure over four weeks carried about 6.4 mmol, roughly 400 mg.²

Some capsules add potassium, one of the electrolytes, and at 15% of the reference intake or more it carries the authorised wording that it contributes to the maintenance of normal blood pressure and to normal muscle function. Beetroot and nitrate have no authorised claim in Great Britain, so no beetroot capsule may claim stamina or circulation; in beetroot gummies that add vitamins, any authorised wording attaches to those vitamins, not to the beetroot.¹⁴

How much beetroot did the trials use, and when?

The 2009 Exeter study gave eight men 500 ml of beetroot juice a day (about 5.6 mmol of nitrate) for six days: plasma nitrite roughly doubled, resting systolic pressure was 8 mmHg lower and moderate exercise used less oxygen.⁴ The 2013 dose-response study in 10 men set the practical rules: nitrite peaks two to three hours after a dose, 4.2 mmol produced no measurable change, 8.4 mmol taken 2.5 hours before exercise cut the oxygen cost of moderate exercise by 1.7% (P = 0.06, not statistically significant) and extended time to exhaustion by 14%, and 16.8 mmol gave no further gain in exercise tolerance.¹ Across 20 meta-analyses pooled in 2025 the effect on time to exhaustion is small (standardised mean difference 0.33), larger at 6 mmol a day or more taken for more than three days; four other measures improved and the rest did not, most reviews were rated low or critically low quality, and participants were mostly men.⁵

Do beetroot capsules lower blood pressure?

The trials that lowered blood pressure used juice at doses far above what capsules declare, so they are evidence about juice. In 68 people with hypertension, half already on treatment, 250 ml of nitrate-rich beetroot juice a day for four weeks lowered clinic blood pressure by 7.7/2.4 mmHg and 24-hour pressure by 7.7/5.2 mmHg against the same juice with the nitrate removed, with no fading over the month.² Across 16 short crossover trials in 254 people the fall was 4.4 mmHg systolic; across 11 trials in 349 people with diagnosed hypertension it was 5.3 mmHg in clinic systolic pressure, with no significant effect on 24-hour pressure, graded low certainty.^{6, 7} No beetroot capsule may make a blood pressure claim for its beetroot or nitrate; where potassium wording appears on a label, it is the mineral's.¹⁴

Who should avoid beetroot supplements, or ask first?

People on blood pressure medicines. The body turns nitrate into nitric oxide, which widens blood vessels, so it can add to the effect of the tablets. The four-week trial randomised 34 patients already on treatment and reported no serious adverse events, under monitoring; at home, dizziness on standing is the sign to watch, and a GP or pharmacist should know before you start.² The same applies if your pressure already runs low.

Kidney disease, and medicines that raise potassium. A capsule that declares potassium adds to the day's total. The NHS asks people on ramipril to tell their doctor about medicines that raise blood potassium, such as spironolactone, amiloride and potassium itself;¹⁶ anyone with chronic kidney disease, or on an ACE inhibitor, an angiotensin receptor blocker or one of those medicines, should ask before adding a supplement that contains it.

Calcium oxalate kidney stones. Beetroot sits with spinach and rhubarb among the common high-oxalate foods.¹³ Anyone who has passed an oxalate stone and been told to limit those foods should count beetroot powder in the same tally, and drink the 2.5 to 3 litres of water a day the NHS advises to help prevent stones.⁹

Pregnancy and breastfeeding. The trials cited here did not study beetroot supplements in pregnancy; the food is fine, and supplement labels say consult a GP.

Anticoagulants. No interaction with warfarin or the newer anticoagulants was reported in the trials cited here; tell the anticoagulant clinic anyway.

Why is my urine pink after beetroot?

Beeturia, pink or red urine after beetroot, affects about 10 to 14% of people and is harmless. The pigment, betanin, is broken down by stomach acid in most people but survives in some and is absorbed from the colon.^{8, 10} It is reported more often in people with iron deficiency or malabsorption, a reason to have iron checked if the colour is new and persistent; raw beetroot itself has 1.0 mg of iron per 100 g.^{10, 15}

Does mouthwash cancel the effect?

Yes, for the nitrate part. Bacteria in the mouth reduce nitrate to nitrite, which the body turns into nitric oxide; in a crossover study in seven healthy volunteers, a chlorhexidine mouthwash used before a nitrate load stopped the conversion to nitrite in saliva and markedly blunted the rise in blood nitrite.¹¹ Skip antibacterial mouthwash around the dose.

What we don't know

No trial has tested nitrate at the amounts capsules declare; the lowest amount in the dose-response study, 4.2 mmol, produced no measurable change in the exercise response.¹ Whether the exercise effect holds for women is open, because most participants in the reviews were men.⁵ The blood pressure fall in hypertension is graded low certainty, and 400 mg of nitrate a day as juice did not lower pressure over 12 weeks in the Dutch trial.^{3, 7}

Frequently asked questions

Is it safe to take beetroot capsules every day?

The European Food Safety Authority's acceptable daily intake for nitrate is 3.7 mg per kilogram of body weight, about 260 mg a day for a 70 kg adult; a trial dose of 6 to 8 mmol exceeds it, while a capsule declaring tens of milligrams sits far below it.¹²

How long do beetroot capsules take to work?

The trials measured effects two to three hours after a single dose of juice and after six days to four weeks of daily use.^{1, 2, 4} Those are juice figures.

Can I take beetroot if I take blood pressure medicines?

Not without telling your GP or pharmacist first. The effects can add, and if your pressure already runs low or you feel dizzy on standing, the answer may be no.

Which beetroot capsules are best?

The one whose label states milligrams of nitrate per serving, not only grams of beetroot, so you can set it against the 372 to 496 mg the trials used.

Sources

1. Wylie LJ, et al. Beetroot juice and exercise: pharmacodynamic and dose-response relationships. Journal of Applied Physiology, 2013. Randomised placebo-controlled crossover trial, 10 men; funding not named on PubMed. PubMed 23640589.
2. Kapil V, et al. Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebo-controlled study. Hypertension, 2015. Randomised trial, 68 adults, 4 weeks; British Heart Foundation-funded, one author declares a company directorship. PubMed 25421976.
3. van der Avoort CMT, et al. Increasing nitrate-rich vegetable intake lowers ambulatory blood pressure in (pre)hypertensive middle-aged and older adults: a 12-wk randomized controlled trial. Journal of Nutrition, 2021. Randomised controlled trial, 77 adults, 12 weeks; funding not named on PubMed. PubMed 34236392.
4. Bailey SJ, et al. Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. Journal of Applied Physiology, 2009. Randomised placebo-controlled crossover trial, 8 men, 6 days; funding not stated on PubMed. PubMed 19661447.
5. Poon ETC, et al. Dietary nitrate supplementation and exercise performance: an umbrella review of 20 published systematic reviews with meta-analyses. Sports Medicine, 2025. Umbrella review, 20 meta-analyses, 180 studies, 2,672 participants; no specific funding, no conflicts declared. PubMed 40085422.
6. Siervo M, et al. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis. Journal of Nutrition, 2013. Meta-analysis, 16 crossover trials, 254 participants; funding not stated on PubMed. PubMed 23596162.
7. Grönroos R, et al. Effects of beetroot juice on blood pressure in hypertension according to European Society of Hypertension guidelines: a systematic review and meta-analysis. Nutrition, Metabolism and Cardiovascular Diseases, 2024. Meta-analysis, 11 randomised trials, 349 patients; no competing interests declared. PubMed 39069465.
8. Eastwood MA, Nyhlin H. Beeturia and colonic oxalic acid. QJM, 1995. Laboratory, animal and volunteer study; Wellcome Trust-funded. PubMed 7493168.
9. NHS. Kidney stones. Page last reviewed 17 September 2026. nhs.uk.
10. Watts AR, et al. Beeturia and the biological fate of beetroot pigments. Pharmacogenetics, 1993. Volunteer study, 100 adults, with rat experiments; funding not named on PubMed. PubMed 8148871.
11. Govoni M, et al. The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash. Nitric Oxide, 2008. Crossover study, 7 healthy volunteers; funding not named on PubMed. PubMed 18793740.
12. European Food Safety Authority. EFSA confirms safe levels for nitrites and nitrates added to food. Agency statement, 15 June 2017. efsa.europa.eu.
13. Noonan SC, Savage GP. Oxalate content of foods and its effect on humans. Asia Pacific Journal of Clinical Nutrition, 1999. Narrative review; funding not stated on PubMed. PubMed 24393738.
14. Great Britain nutrition and health claims (NHC) register, potassium entries. Updated 19 May 2026. gov.uk.
15. Public Health England. Composition of Foods Integrated Dataset (CoFID) 2021. Food composition dataset. gov.uk.
16. NHS. Taking ramipril with other medicines and herbal supplements. Page last reviewed 18 March 2026. nhs.uk.

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