Beetroot Supplements: The Nitrate That Isn't on the Label
Educational overview — not medical advice. Beetroot is generally well tolerated; the cautions that matter are kidney stones (oxalate) and additive blood-pressure lowering — see for blood pressure.
Beetroot's active ingredient is inorganic nitrate — the body turns nitrate → nitrite → nitric oxide (Lundberg 2008). That nitric oxide modestly lowers blood pressure (systolic ~−3.9 mmHg; He 2021) and gives a small, real endurance benefit (Poon 2025) — but not strength. The studied dose is ~6–13 mmol nitrate/day (~372–800 mg). The catch that defines this whole category: almost no product discloses its nitrate — of 16 we track, only 1 prints an actual nitrate figure.
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Start here
What beetroot is (and what actually does the work)
Beetroot is marketed for "nitric oxide," and that part is true — but the ingredient responsible is inorganic nitrate (NO3-) concentrated in the root. Once swallowed, oral bacteria and then the body reduce it along the nitrate → nitrite → nitric oxide pathway (Lundberg 2008). Nitric oxide relaxes blood vessels and improves the oxygen cost of exercise. What does not do the work: the beetroot mass itself, the red betalain pigment, or the antioxidants. That single fact — the dose is nitrate, not beetroot — is why the milligram number on almost every label is close to meaningless.
Does it work? (the short version)
Yes, modestly, in two places. Blood pressure: a meta-analysis of 22 studies found beetroot lowered systolic pressure by about 3.9 mmHg (and diastolic ~2.6 mmHg), with the largest effect in adults over 65, with obesity, or with prehypertension (He 2021). Endurance: a 2025 umbrella review of 20 systematic reviews (180 studies) found genuine ergogenic effects on time-to-exhaustion, distance, and muscular endurance — more pronounced at ≥6 mmol/day taken for more than 3 days — but no effect on strength, with the underlying evidence graded low to critically low (Poon 2025). Small and specific, not dramatic.
The one-line takeaway The evidence is for a nitrate dose you mostly can't verify from the bottle. Of the 16 products we track, only 1 discloses an actual nitrate figure and 15 leave it a black box — so shop on disclosure first, not on the whole-root milligram number.
The buying problem: nitrate, not milligrams
Two traps. First, the label: "beetroot 1,000 mg," "20:1 extract," and "6,000 mg equivalent" all describe root or blend weight, not nitrate — and independent lab testing has found nitrate varying more than 200-fold between products (the nitrate label trap). Second, the comparison: because nitrate is almost never disclosed, cost per unit of active nitrate is literally incomputable for most products, so the usual value ranking breaks down (best beetroot by disclosure). The honest move is to prioritize any product that actually prints a nitrate figure — even though, today, the one that does still falls short of the studied dose.
On this page
Beetroot Benefits: What the Evidence Actually Shows
Looking for a product that actually discloses its nitrate? See the best beetroot ranked by disclosure and cost per 100 mg nitrate →
What actually does the work: nitrate, not beetroot
Every benefit claim attached to beetroot traces back to one compound: inorganic nitrate (NO3-), concentrated in the root. Swallowed nitrate is reduced by bacteria on the tongue to nitrite, then converted in the body to nitric oxide, which relaxes blood vessels and improves the oxygen efficiency of exercising muscle — the nitrate→nitrite→nitric oxide pathway (Lundberg 2008, PMID: 18167491). The beetroot mass itself, the red betalain pigment, and the antioxidants marketed alongside it are not what's driving the studied effects. That matters for shopping: the milligram number on most labels describes root or extract weight, not nitrate, and independent testing has found nitrate content varying more than 200-fold between products — covered in full on the nitrate label trap.
Exercise performance: real, modest, and better for recreational effort than for elite athletes
The best current summary is a 2025 umbrella review of 20 systematic reviews (180 studies, 2,672 participants), which found dietary nitrate improved time-to-exhaustion tasks, total distance covered, and muscular endurance, with the improvements more pronounced at a dose of at least 6 mmol nitrate/day (~372 mg) sustained for more than 3 days — but no significant improvement on several other performance measures, and review quality overall rated low to critically low (Poon 2025, PMID: 40085422). An earlier meta-analysis of 76 trials found the same pattern: a small but statistically significant benefit for time-to-exhaustion, but no significant benefit for head-to-head time-trial performance (McMahon 2017, PMID: 27600147). The underlying mechanism is measurable in the lab: in nine moderately trained men, three days of dietary nitrate cut the oxygen cost of submaximal cycling and raised gross exercise efficiency from 19.7% to 21.1% (Larsen 2007, PMID: 17635415).
Training status is the honest complication. McMahon's 76-trial meta-regression didn't find fitness level to significantly moderate the pooled effect, but individual trials in highly trained populations tell a more discouraging story: an acute nitrate dose produced no measurable change in running economy or 5K time-trial performance in elite cross-country skiers (Sandbakk 2015, PMID: 25445632). A plausible explanation is a ceiling effect — elite endurance athletes already have highly efficient oxidative metabolism, leaving less room for a nitrate-driven improvement. If you're a recreational or moderately trained exerciser, the trial base is more encouraging than if you're already training at an elite level.
Blood pressure: the other well-evidenced benefit
Beetroot's blood-pressure effect is the more thoroughly studied of the two: a meta-analysis of 22 studies found systolic pressure fell by about 3.9 mmHg, largest in adults who are older, obese, or prehypertensive (He 2021, PMID: 33905826). It's a genuine, mechanistically grounded effect, and it deserves its own page rather than a re-argument here — including the durability limits and the oxalate/kidney-stone and medication cautions that matter most. See beetroot for blood pressure for the full picture.
Two things that quietly cancel the benefit
Dose you can't verify. The studied range is nitrate, not beetroot: roughly 6–13 mmol/day (~372–800 mg), and the difference between hitting that range and missing it is not academic. In a month-long trial, 6 mmol/day of nitrate reduced submaximal exercise oxygen cost, while 3 mmol/day — half the dose — produced no measurable effect at any point across four weeks of daily dosing (Wylie 2016, PMID: 27093910). Since almost no retail label discloses actual nitrate content, most people supplementing "beetroot" have no way to know which side of that line they're on. See the dosage guide for the conversion math.
Antibacterial mouthwash. The nitrite conversion step happens courtesy of bacteria living on your tongue, and disrupting them disrupts the whole pathway. A chlorhexidine-based antiseptic mouthwash cut oral nitrite production by 90% and plasma nitrite by 25% in healthy volunteers, and their blood pressure rose 2–3.5 mmHg within a day of starting the rinse (Kapil 2013, PMID: 23183324). A separate trial found the same strong mouthwash blunted the plasma nitrite rise from beetroot juice and reduced the usual blood-pressure response during light exercise, while a weaker, non-chlorhexidine rinse had less effect (McDonagh 2015, PMID: 26332900). If you use a strong antiseptic mouthwash daily, you are working against the exact mechanism a nitrate supplement depends on.
Timing. Trials that test a performance or blood-pressure effect commonly measure it starting around 2 hours after an acute nitrate dose, which lines up with how long the tongue-bacteria-to-nitric-oxide conversion takes (Wylie 2016, above). In practice, that's why concentrated nitrate shots are typically timed roughly 2–3 hours before a workout or event rather than taken immediately beforehand.
What's marketed but not well supported
Beetroot is also sold on broader "detox," antioxidant, and general anti-inflammatory language. That framing rests mostly on beetroot's betalain pigments and polyphenols in isolated lab and animal work, not on the nitrate-driven, human-trial evidence behind the blood-pressure and endurance effects above — and it isn't backed by the kind of clinical-outcome trials this page otherwise cites. Treat those claims as marketing, not as an evidenced third benefit.
One more thing worth naming so it doesn't alarm anyone: beeturia, red or pink urine (and sometimes stool) after eating beets, happens in roughly 14% of people. It's the beet pigment betalain surviving digestion rather than being broken down, unrelated to iron status for most people who experience it, and it has nothing to do with the nitrate dose or the benefits above — it's harmless (Eastwood 1995, PMID: 7493168).
Beetroot's claimed benefits, graded by evidence
| Claimed benefit | Evidence grade | What the trials show | Practical note |
|---|---|---|---|
| Blood pressure | Real, meta-analysis-level | Systolic ~−3.9 mmHg (22-study meta-analysis) | Full detail on the dedicated page |
| Endurance capacity (time-to-exhaustion, distance, muscular endurance) | Real but small | Improved at ≥6 mmol/day nitrate for 3+ days; no effect on strength | More consistent in recreational/moderately trained exercisers |
| Head-to-head time-trial performance | Weak / not significant pooled | 76-trial meta-analysis found no significant overall effect | Don't expect a race-day PR from nitrate alone |
| Elite/highly-trained athlete performance | Weak to null | No effect on economy or 5K time in elite cross-country skiers | Likely a ceiling effect — less room to improve already-efficient metabolism |
| "Detox," general antioxidant, anti-inflammatory claims | Not established in human trials | Rests on isolated pigment/polyphenol lab data, not clinical outcomes | Marketing language, not the nitrate mechanism this page covers |
Beetroot Side Effects: Beeturia, GI Effects & Real Cautions
Looking for a product that actually discloses its nitrate? See the best beetroot ranked by disclosure and cost per 100 mg nitrate →
Beeturia: the "side effect" most people actually notice
The thing most likely to make you double-take after eating beets or taking a beetroot supplement is beeturia — red or pink discoloration of urine, and sometimes stool. It's caused by betalain, the red pigment in beetroot, surviving digestion in some people instead of being broken down. Classic research on the phenomenon found it happens in about 14% of people, and traced the mechanism: betalain is normally decolorized by stomach acid and colonic bacteria, but oxalic acid protects its red color, and in people who don't fully decolorize it, the pigment is absorbed further down the gut and shows up in urine and stool (Eastwood & Nyhlin 1995, PMID: 7493168).
This is a pigment quirk, not a warning sign. It isn't connected to iron status, kidney function, or the nitrate dose that drives beetroot's actual effects. A 12-week trial giving older adults a full studied dose of standardized beetroot extract (548 mg, 8.8 mmol nitrate/day) documented it in plain terms: participants in the beetroot group reported pink or reddish coloring in their urine and stools, which the researchers described as common after consuming beetroot and not indicative of a health problem — and the trial otherwise concluded beetroot extract was safe and well tolerated over the full 12 weeks (Pinheiro et al. 2024, PMID: 38931296). If you notice it, it's a sign the beets are working their way through you, not that anything is wrong.
Gastrointestinal effects: uncommon, and not the beetroot reputation you might expect
Some individual trials report abdominal pain, diarrhea, nausea, or general digestive discomfort with beetroot juice, particularly at large single doses. But taken as a body of evidence, GI upset is not a defining feature of beetroot the way it is for some other supplements. A systematic review and dose-response meta-analysis pooling 17 randomized controlled trials that reported adverse-event data found that beeturia was the adverse effect most consistently described, that abdominal pain, diarrhea, nausea, and headache were reported in only some individual studies, and that dietary nitrate supplementation did not lead to a statistically significant increase in adverse events compared with placebo (risk ratio 1.00) or in study withdrawals (risk ratio 0.42) (Norouzzadeh et al. 2025, PMID: 40128734). Consistent with that, the 12-week extract trial at the full studied dose reported no gastrointestinal adverse events in the beetroot group at all (Pinheiro 2024, above). If you do notice mild stomach upset, starting at a lower dose or a smaller serving of juice and building up is a reasonable, low-risk adjustment.
The one real medication caution: additive blood-pressure lowering
This is the caution worth actually naming, not the GI upset. Beetroot works by raising nitric oxide, which relaxes blood vessels and modestly lowers blood pressure. That's the whole point of the supplement — but it also means stacking it with something else that lowers blood pressure can add up to more than either alone. This matters for two groups: people on antihypertensive medication, and people taking a PDE5 inhibitor such as sildenafil (Viagra). The strict, well-known contraindication between PDE5 inhibitors and nitrates applies to pharmaceutical/organic nitrates like nitroglycerin, not to dietary inorganic nitrate from beets — sildenafil is not considered contraindicated with dietary nitrate (Schwartz & Kloner 2010, PMID: 20606131). But the lower-grade, genuine concern — additive blood-pressure lowering, with symptoms like lightheadedness — still applies, since beetroot's own effect is real and documented (systolic ~−3.9 mmHg in a meta-analysis of 22 studies; He et al. 2021, PMID: 33905826).
The practical takeaway: this isn't a hard "don't combine" rule, but it is a "mention it to your doctor" one, especially if you're titrating a blood-pressure medication or regularly using a PDE5 inhibitor. For the full evidence on beetroot's blood-pressure effect, how durable it is, and how this caution fits in, see beetroot for blood pressure.
Oxalate and kidney stones: a caution for a minority, not everyone
Beets are naturally high in oxalate, and dietary oxalate is a recognized contributor to urinary oxalate excretion, the main driver of calcium-oxalate kidney stones, the most common stone type (Massey et al. 1993, PMID: 8335871). This isn't a reason for most people to avoid beetroot — it's a caution specifically for people who form calcium-oxalate stones or have been told by a clinician to watch their oxalate intake. If that's you, discuss regular use of concentrated beetroot juice or extract with your doctor before making it a daily habit. Full detail, including the specific oxalate figures for beet juice, is on the blood-pressure page.
Antibacterial mouthwash: it blunts the benefit, it doesn't cause harm
This isn't a safety caution so much as a "don't waste your dose" one, but it belongs on this page because people ask about it as a side effect. Beetroot's nitrate has to be converted to nitrite by bacteria living on your tongue before it becomes the nitric oxide that does anything — and a strong antiseptic mouthwash disrupts that step. A chlorhexidine-based mouthwash cut oral nitrite production by 90% and reduced plasma nitrite in one trial (Kapil et al. 2013, PMID: 23183324), and a separate trial found the same strong mouthwash blunted the plasma-nitrite rise and blood-pressure response from beetroot juice specifically, while a weaker, non-chlorhexidine rinse had less effect (McDonagh et al. 2015, PMID: 26332900). If you use a strong antibacterial mouthwash daily, especially around when you take beetroot, you're not risking anything — you're just quietly cancelling out the reason you're taking it.
Beetroot side effects at a glance
| Effect / caution | How common per our sources | What it means | What to do |
|---|---|---|---|
| Beeturia (red/pink urine or stool) | ~14% of people (Eastwood 1995); the most consistently reported effect (Norouzzadeh 2025) | Harmless pigment quirk, unrelated to the nitrate dose | Nothing — expect it and ignore it |
| GI upset (abdominal pain, diarrhea, nausea) | Reported in some individual trials; no significant increase in adverse events overall across 17 RCTs (RR 1.00) | Uncommon, usually mild if it occurs | Lower the dose/serving size if it happens |
| Additive blood-pressure lowering | Expected mechanistically; beetroot itself lowers systolic BP ~3.9 mmHg | Can stack with antihypertensives or PDE5 inhibitors — not the nitroglycerin contraindication | Discuss with a doctor if you take BP medication or a PDE5 inhibitor |
| Oxalate / kidney stones | Relevant only to calcium-oxalate stone formers | Beets are oxalate-rich and can raise urinary oxalate | Talk to a doctor first if you form calcium-oxalate stones |
| Antibacterial mouthwash | Documented to cut oral nitrite ~90% in trials | Blunts the nitrate→nitrite→nitric oxide effect — not a safety risk | Avoid strong antiseptic rinses around dosing |
Frequently asked questions
What is the active ingredient in beetroot?
Inorganic nitrate (NO3-), converted nitrate → nitrite → nitric oxide (Lundberg 2008). Not the beetroot mass, pigment, or antioxidants — which is why whole-root milligrams don't tell you the dose that matters.
Does beetroot actually work?
Modestly. Blood pressure: systolic ~−3.9 mmHg, biggest in older/obese/prehypertensive people (He 2021). Endurance: real but small, stronger at ≥6 mmol/day for 3+ days; no strength effect; evidence quality low (Poon 2025).
How much should I take?
Measured in nitrate: ~6–13 mmol/day (~372–800 mg; 1 mmol = 62 mg). Minimum effective ~6 mmol (372 mg); plateau ~8.4 mmol (~520 mg). But most labels don't disclose nitrate, so you usually can't confirm the dose.
Why is comparing products so hard?
The number that matters — nitrate per serving — is almost never printed; testing found >200-fold variation. Only 1 of 16 products we track discloses a nitrate figure (and even that is ~6% of the studied floor), so a cost-per-active ranking is impossible for the rest.
What are beetroot supplements actually proven to do?
Two things have real trial support: a modest reduction in blood pressure (systolic down roughly 3.9 mmHg in a meta-analysis of 22 studies) and a small improvement in endurance exercise capacity, mainly time-to-exhaustion, total distance, and muscular endurance, with no effect on strength or 1-rep-max efforts. Both trace back to the same mechanism: beetroot is a concentrated source of inorganic nitrate, which your body converts to nitrite and then nitric oxide. Everything else marketed under "beetroot benefits" — general detox, broad anti-inflammatory effects, cognitive claims — has little or no direct trial support at supplement doses.
Does beetroot help exercise performance for recreational exercisers, or only trained athletes?
The clearest benefit shows up in time-to-exhaustion and endurance-capacity tests, less so in head-to-head time trials. A 2025 umbrella review of 20 meta-analyses found the effect was more pronounced at a nitrate dose of at least 6 mmol/day taken for more than 3 days. Where it gets murkier is training status: a 2015 trial in elite cross-country skiers found no effect on running economy or 5K performance from an acute nitrate dose, and a 76-trial meta-analysis found time-trial performance overall was not significantly improved, even though it didn't find fitness level to be a statistically significant moderator across all trials pooled together. The honest summary: real evidence for endurance capacity, especially in people who aren't already highly trained, and much weaker evidence that it moves the needle for elite athletes or head-to-head races.
When should I take beetroot before a workout, and does mouthwash cancel it out?
Trials that measure a performance effect typically test it starting around 2 hours after an acute nitrate dose, which is roughly how long it takes your body to convert swallowed nitrate into nitrite via bacteria on your tongue, then into nitric oxide. That conversion step is also the vulnerability: a chlorhexidine-based antiseptic mouthwash cut oral nitrite production by 90% and blunted the usual blood-pressure and exercise response in separate trials. If you rinse with a strong antibacterial mouthwash right before or after your nitrate dose, you can meaningfully blunt the effect you're trying to get.
Is red or pink urine after eating beetroot (beeturia) something to worry about?
No — it's harmless. Beeturia is the passage of red beetroot pigment (betalain) into urine or stool, and it happens in roughly 14% of people. It comes from the pigment surviving digestion rather than being broken down in the stomach and gut, and it isn't connected to the nitrate content or the blood pressure and exercise effects at all. It can look alarming the first time you notice it, but it's a pigment quirk, not a sign that anything is wrong.
Is red or pink urine after eating beetroot (beeturia) dangerous?
No — it's harmless. Beeturia is the passage of red beetroot pigment (betalain) into urine or stool, and it happens in about 14% of people. A 12-week trial that gave older adults a full studied dose of beetroot extract documented it directly: participants in the beetroot group reported pink or reddish urine and stool, described by the researchers as common after consuming beetroot and not a sign of a health problem. It comes from the pigment surviving digestion rather than being broken down in the stomach and gut, and it has nothing to do with the nitrate dose or with kidney or liver function. It can look alarming the first time, especially if you didn't connect it to the beets, but it isn't something to worry about.
What are the actual side effects of beetroot supplements?
Beeturia (pink/red urine or stool, harmless) is by far the most commonly reported effect. Gastrointestinal symptoms — abdominal pain, diarrhea, nausea, or general digestive discomfort — show up in some trials, but not consistently, and a systematic review of 17 randomized controlled trials found dietary nitrate supplementation did not significantly increase adverse events overall compared with placebo. A 12-week trial at the full studied dose in older adults reported no gastrointestinal side effects at all. Beetroot is one of the better-tolerated supplements on this site; the cautions that matter are about interactions, not about beetroot itself being irritating.
Can I take beetroot if I take blood pressure medication or a PDE5 inhibitor like sildenafil (Viagra)?
Talk to your doctor first, but understand what the actual risk is. Dietary nitrate from beetroot is not the same as the pharmaceutical nitrates (like nitroglycerin) that are strictly contraindicated with PDE5 inhibitors — sildenafil is not considered contraindicated with dietary nitrate. The real, lower-grade concern is additive blood-pressure lowering: beetroot itself modestly lowers blood pressure, so stacking it with a blood-pressure medication or a PDE5 inhibitor could add up to a bigger drop than either alone, with symptoms like lightheadedness. It's a caution to monitor and discuss, not a hard contraindication. Full detail is on our beetroot and blood pressure page.
Does mouthwash cancel out the effects of beetroot?
It can blunt them, though it isn't a safety risk. The nitrate-to-nitrite conversion that makes beetroot work happens courtesy of bacteria living on your tongue. A chlorhexidine-based antiseptic mouthwash cut oral nitrite production by 90% in one trial, and a separate trial found the same strong mouthwash blunted the usual plasma-nitrite and blood-pressure response to beetroot juice. If you rinse with a strong antibacterial mouthwash around when you take beetroot, you're working against the mechanism the supplement depends on — not causing harm, just wasting the dose.
Is beetroot safe if I am prone to kidney stones?
Use caution if you form calcium-oxalate stones specifically. Beets are high in oxalate, and dietary oxalate is a recognized contributor to urinary oxalate, the main risk factor for calcium-oxalate stones. This isn't a concern for most people, but if you have a personal history of calcium-oxalate stones, talk to your doctor before adding concentrated beetroot juice or extract regularly. Full detail is on our beetroot and blood pressure page.
Related guides
- L-Citrulline — the other nitric-oxide precursor (with its own label trap)
- Taurine — a sulfur amino acid with real blood-pressure evidence
- Beta-Alanine — the carnosine-loading amino acid for 1–4 min efforts
Sources
- Lundberg JO, et al. "The nitrate-nitrite-nitric oxide pathway in physiology and therapeutics." Nat Rev Drug Discov. 2008. PMID: 18167491
- Poon ET, et al. "Dietary Nitrate Supplementation and Exercise Performance: An Umbrella Review." Sports Med. 2025. PMID: 40085422
- He Y, et al. "The effect of beetroot supplementation on blood pressure in older adults: a meta-analysis." Nitric Oxide. 2021. PMID: 33905826
- Full product dataset: /beetroot/cost-by-brand.json (CC BY 4.0).
- 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. PMID: 27600147
- Larsen FJ, Weitzberg E, Lundberg JO, Ekblom B. "Effects of dietary nitrate on oxygen cost during exercise." Acta Physiol (Oxf). 2007;191(1):59-66. PMID: 17635415
- Sandbakk SB, et al. "Effects of acute supplementation of L-arginine and nitrate on endurance and sprint performance in elite athletes." Nitric Oxide. 2015;48:10-5. PMID: 25445632
- Wylie LJ, et al. "Dose-dependent effects of dietary nitrate on the oxygen cost of moderate-intensity exercise: Acute vs. chronic supplementation." Nitric Oxide. 2016;57:30-39. PMID: 27093910
- Kapil V, et al. "Physiological role for nitrate-reducing oral bacteria in blood pressure control." Free Radic Biol Med. 2013;55:93-100. PMID: 23183324
- McDonagh ST, Wylie LJ, Winyard PG, Vanhatalo A, Jones AM. "The Effects of Chronic Nitrate Supplementation and the Use of Strong and Weak Antibacterial Agents on Plasma Nitrite Concentration and Exercise Blood Pressure." Int J Sports Med. 2015;36(14):1177-85. PMID: 26332900
- Eastwood MA, Nyhlin H. "Beeturia and colonic oxalic acid." QJM. 1995;88(10):711-7. PMID: 7493168
- Pinheiro VDS, et al. "Evaluation of 12-Week Standardized Beetroot Extract Supplementation in Older Participants: A Preliminary Study of Human Health Safety." Nutrients. 2024;16(12):1942. PMID: 38931296
- Norouzzadeh M, et al. "Plasma nitrate, dietary nitrate, blood pressure, and vascular health biomarkers: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials." Nutr J. 2025;24:47. PMID: 40128734
- Schwartz BG, Kloner RA. "Drug interactions with phosphodiesterase-5 inhibitors used for the treatment of erectile dysfunction or pulmonary hypertension." Circulation. 2010;122(1):88-95. PMID: 20606131
- Massey LK, et al. "Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate kidney stones." J Am Diet Assoc. 1993;93(8):901-6. PMID: 8335871