Beetroot vs Citrulline: Two Nitric Oxide Routes, Both With Small Payoffs
Beetroot nitrate has the bigger body of evidence, mostly for endurance-type tasks in recreational exercisers. Citrulline's signal is a few extra reps in the gym. Both effects are small, and the only trial with separate groups for each was tiny.
By Kymata Health Editorial Published Last checked
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Key takeaways
From 12 sources- Both raise nitric oxide by different routes: nitrate from beetroot depends on bacteria in the mouth, and citrulline is partly converted to arginine in the body78.
- Across 20 meta-analyses, nitrate improved time to exhaustion with a small effect (SMD 0.33), more so at 372 mg (6 mmol) a day or more for longer than 3 days, though most of the reviews were rated low or critically low quality1.
- In 80 crossover trials, nitrate's small benefit was not seen in studies of women only or in well-trained endurance athletes2.
- Citrulline malate was linked to a small overall performance gain across 30 trials (g = 0.16), with low to very low certainty4, and citrulline showed no endurance benefit in 9 studies6.
- The only trial we found with separate beetroot and citrulline groups had 8 triathletes per group, and only the combination differed from placebo on the main fitness test12.
What this article covers
2 evidence profilesThe evidence, graded
Pulled from the trial tables in our evidence profiles. Grades follow our evidence-grading policy.
Graded findings
4 rows- CGrade COverall exercise performance (citrulline malate)Improved Citrulline malate was linked to a small overall improvement in exercise performance (g = 0.16), with wide prediction intervals and limited statistical power. Perceived exertion did not change significantly. GRADE certainty was low to very low.Citrulline (L-citrulline and citrulline malate) · Meta-analysis · n=644 · 2026 · PMID 42356270
- CGrade CRepetitions to failure in strength trainingImproved Citrulline malate increased total repetitions by about 3 (6.4%) versus placebo, a small effect (SMD 0.196). Lower-body results showed a tendency for an effect; upper-body results were not significant.Citrulline (L-citrulline and citrulline malate) · Meta-analysis · n=137 · 2021 · PMID 34010809
- CGrade CEndurance: time to exhaustion and time to completionNo effect No significant difference from control in time to exhaustion (SMD 0.03) or time to completion (SMD -0.07).Citrulline (L-citrulline and citrulline malate) · Meta-analysis · n=158 · 2023 · PMID 37155582
- BGrade BExercise performance (time to exhaustion, endurance, power)Improved Small improvements in time to exhaustion (SMD 0.33), distance covered, muscular endurance and peak power; no significant effect on other performance outcomes. Most included reviews were rated low or critically low quality.Beetroot · Meta-analysis · n=2,672 · 2025 · PMID 40085422
Where these trials agree: Citrulline (L-citrulline and citrulline malate) and performance, counted row by row in the Consensus finder.
Two routes to nitric oxide
Beets are one of the richest food sources of inorganic nitrate, which the body can convert into nitric oxide, a vasodilator10. A key step happens in the mouth, where bacteria reduce nitrate to nitrite8. In 7 volunteers, an antibacterial mouthwash abolished that conversion in saliva and markedly blunted the rise in blood nitrite after a nitrate dose8.
Citrulline takes a different path. It is readily absorbed and at least partly converted to arginine7, which the body then converts to nitric oxide10. In 20 healthy volunteers, oral L-citrulline raised blood arginine more effectively than arginine itself, and the highest dose, 3 g twice a day, raised markers of nitric oxide signalling7. Blood vessel dilation did not improve with any dose in that study7.
Beetroot: best for endurance-type tasks in recreational exercisers
A 2025 umbrella review pooled 20 meta-analyses covering 180 studies and 2,672 participants1. Nitrate improved time to exhaustion (SMD 0.33), total distance covered, muscular endurance and peak power, but not the other performance outcomes measured1. Gains were larger with at least 6 mmol (372 mg) of nitrate a day taken for more than 3 days1.
Who benefits matters. In a meta-analysis of 80 crossover trials, the overall effect was small (d = 0.174) and was not seen in the 6 women-only studies or in the 26 studies of well-trained endurance athletes2. An earlier meta-analysis found a significant effect in time-to-exhaustion tests but not in time trials3.
Citrulline: a few extra reps, no endurance benefit
A 2026 meta-analysis of 30 trials with 644 participants linked citrulline malate to a small overall improvement in exercise performance (g = 0.16), with wide prediction intervals and limited statistical power4. Perceived exertion did not change significantly, the certainty of evidence was low to very low, and the authors said reliable dosing and timing have not been established4.
The clearest signal is repetitions. In 8 studies with 137 people, mostly strength-trained men, 6 to 8 g of citrulline malate taken 40 to 60 minutes before training added about 3 repetitions (6.4%) versus placebo, a small effect5. The lower-body result was only a tendency, and the upper-body result was not significant5.
For endurance, 9 studies with 158 young adults found no significant difference from control after acute doses in time to exhaustion or time to completion6. For form and dose details, see citrulline malate vs L-citrulline and what the citrulline pump trials show.
Taking both together
The closest to a head-to-head test is a 9-week trial in 32 trained male triathletes, 8 per group, given placebo, 3 g of citrulline, beetroot extract with 300 mg of nitrate, or both, each day12. Muscle-damage markers did not differ, and Cooper test distance improved more with the combination than with placebo or citrulline alone12. The abstract does not report a comparison of beetroot alone with citrulline alone12.
In a 2-month training trial in 24 healthy young adults, a nitrate-rich salad plus a citrulline drink (520 mg of nitrate and 6 g of citrulline a day) led to a larger gain in knee extensor strength than placebo (5.1 vs 0.2 kg)9. It did not change vascular function or improve maximal aerobic performance beyond what training achieved9. The trial had no nitrate-only or citrulline-only group, so the two ingredients' effects cannot be separated9.
Safety and practical points
ODS reports no safety concerns with moderate amounts of beetroot juice, about 2 cups a day, for several weeks; the juice can turn urine pink or red, which is not a safety concern10. Beetroot juice also lowers blood pressure: in 11 trials in adults with hypertension, clinic systolic pressure fell 5.31 mmHg versus placebo11, worth knowing if you already take blood pressure medicines.
Because nitrate depends on mouth bacteria, antibacterial mouthwash can blunt the rise in blood nitrite8. The safety of citrulline taken for months at a time has not been adequately studied, and in one trial 6 of 41 weight lifters reported stomach discomfort after taking it10.
Which one fits you
For the full evidence tables, see the citrulline and beetroot pages.
Match the supplement to the kind of training:
- Recreational endurance work, such as runs or rides to exhaustion: nitrate has the stronger evidence, ideally 372 mg a day or more for several days1.
- Well-trained endurance athletes: nitrate's benefit was not seen in this group2.
- High-rep strength sessions: citrulline malate's best evidence is about 3 extra repetitions per session5.
- Blood pressure medicines or daily antibacterial mouthwash: ask your clinician about beetroot, which lowers blood pressure, and note mouthwash can blunt nitrate's effect811.
Quick answers
Common questions
3 answersDoes citrulline raise nitric oxide more than arginine?
It raised blood arginine more effectively than arginine itself in a 20-person trial, and the highest dose raised markers of nitric oxide signalling7.
Is beetroot powder as good as beetroot juice?
Keep reading
Full evidence profiles
Every graded study, studied doses, interactions and safety- Amino acidCitrulline (L-citrulline and citrulline malate)Citrulline is an amino acid made in the body and found in watermelon; the kidneys convert most of it into arginine.CGrade C
- BotanicalBeetrootBeetroot (Beta vulgaris) is a root vegetable rich in inorganic nitrate; concentrated beetroot juice is used for exercise and blood pressure.BGrade B
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Where to buy Citrulline (L-citrulline and citrulline malate)
Products from brands we partner with that contain Citrulline (L-citrulline and citrulline malate). Check the amount per serving against the doses studied, and the label for other ingredients.
Citrulline (L-citrulline and citrulline malate) products from partner brands
3 products Paid links · we earn a commission- Quick pickHerbsProNOW Foods L-Citrulline, 750 mg, 180 Caps
2 capsules: 1,500 mg L-citrulline
$27.91one-timeChecked Oct 14, 2026 - OnnitOnnit Alpha BRAIN Pre-Workout, Tiger’s Blood (20 servings)We use this brand at home. What we useSubscribe & Save 15%
Offer details
Choose Subscribe & Save on the product page; skip, swap or cancel anytime.
- 15% off MSRP on subscription-eligible products unless otherwise noted.
- Does not stack with sale pricing; the greater discount applies.
- Offer terms from Onnit’s site, checked Oct 13, 2026. Offers can change; the brand's checkout is final.
BGrade B, moderate (Grade B) Graded B for its caffeine and beta-alanine; its 2.4 g L-citrulline is below the 3 to 9 g trials used before exercise.
Caution: 200 mg caffeine per scoop: count it toward your daily caffeine.
1 scoop (9.6 g): 2.4 g L-citrulline with 2.4 g beta-alanine and 200 mg caffeine; 20 servings. Trials used 3–9 g L-citrulline
$59.99one-time$51.00subscribeChecked Oct 20, 2026 - OnnitOnnit Total Nitric Oxide, Harvest Fruit (20 servings)We use this brand at home. What we useSubscribe & Save 15%
Offer details
Choose Subscribe & Save on the product page; skip, swap or cancel anytime.
- 15% off MSRP on subscription-eligible products unless otherwise noted.
- Does not stack with sale pricing; the greater discount applies.
- Offer terms from Onnit’s site, checked Oct 13, 2026. Offers can change; the brand's checkout is final.
CGrade C, limited (Grade C) 3 g citrulline malate per scoop, about half the 6 to 8 g trials used before exercise; the beet blend amount is not disclosed.
Caution: Do not combine with nitrate medications or PDE5 inhibitors without a doctor's okay. A 2024 California Prop 65 notice over lead in this product was settled in January 2025.
Onnit does not ship this product to New York.
1 scoop (11.8 g): 3 g L-citrulline DL-malate and 1.4 g arginine nitrate plus a 5.87 g proprietary beetroot and fruit blend; caffeine-free; 20 servings. Trials used 6–8 g citrulline malate
$39.99one-time$34.00subscribeChecked Oct 20, 2026
References
12 sources. Numbers in the text link here.
Sources cited in this article
12 sources- 1Dietary Nitrate Supplementation and Exercise Performance: An Umbrella Review of 20 Published Systematic Reviews with Meta-analysesSports Med, 2025 · PMID 40085422
- 2Ergogenic Effect of Nitrate Supplementation: A Systematic Review and Meta-analysisMed Sci Sports Exerc, 2020 · PMID 32936597
- 3The Effect of Dietary Nitrate Supplementation on Endurance Exercise Performance in Healthy Adults: A Systematic Review and Meta-AnalysisSports Med, 2017 · PMID 27600147
- 4Effects of Citrulline Malate Supplementation on Exercise Performance: A Systematic Review and Three-Level Meta-AnalysisNutrients, 2026 · PMID 42356270
- 5Acute Effect of Citrulline Malate on Repetition Performance During Strength Training: A Systematic Review and Meta-AnalysisInt J Sport Nutr Exerc Metab, 2021 · PMID 34010809
- 6Effects of citrulline on endurance performance in young healthy adults: a systematic review and meta-analysisJ Int Soc Sports Nutr, 2023 · PMID 37155582
- 7Pharmacokinetic and pharmacodynamic properties of oral L-citrulline and L-arginine: impact on nitric oxide metabolismBr J Clin Pharmacol, 2008 · PMID 17662090
- 8The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwashNitric Oxide, 2008 · PMID 18793740
- 9Synergetic Effect of NO Precursor Supplementation and Exercise TrainingMed Sci Sports Exerc, 2020 · PMID 33064413
- 10Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health ProfessionalsNIH Office of Dietary Supplements, 2024
- 11Effects of beetroot juice on blood pressure in hypertension according to European Society of Hypertension Guidelines: A systematic review and meta-analysisNutr Metab Cardiovasc Dis, 2024 · PMID 39069465
- 12Long-Term Combined Effects of Citrulline and Nitrate-Rich Beetroot Extract Supplementation on Recovery Status in Trained Male Triathletes: A Randomized, Double-Blind, Placebo-Controlled TrialBiology (Basel), 2022 · PMID 35053073
Citrulline (L-citrulline and citrulline malate) and other dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Talk to your clinician or pharmacist before starting a supplement, especially if you take prescription medicines. Product links on this page are paid partner links.