Does potassium lower blood pressure?

Yes, modestly, and mainly in people whose blood pressure is already high. A meta-analysis of 22 randomized trials in 1,606 adults found more potassium lowered systolic pressure by 3.49 mm Hg (95% CI 1.82 to 5.15) and diastolic by 1.96 mm Hg. In that analysis the effect was seen in people with hypertension and not in those without it. Most of those trials gave supplements for four weeks or more. Whether potassium from food alone does the same has barely been tested.

Established. In adults with high blood pressure, extra potassium lowers it by a few mm Hg. In a 2017 meta-analysis of randomized trials in hypertensive adults, supplements lowered systolic pressure by 4.48 mm Hg (95% CI 3.07 to 5.90) and diastolic by 2.96 mm Hg. The effect was larger in people eating 4 g of sodium a day or more, in those with low potassium intake to begin with, and in those not taking blood pressure drugs.

What the trials found

The size of the effect depends on who is in the trial. One analysis of 10 trials in 684 adults estimated that a rise of 50 mmol a day in urinary potassium lowered systolic pressure by 5.3 mm Hg in people with hypertension and by 0.5 mm Hg in people without it. Those trials lasted one to six weeks, and the two groups were given different ranges of extra potassium, so the contrast is not like for like. In people with normal blood pressure, a review of six supplements found potassium lowered systolic pressure by 2.10 mm Hg and left diastolic pressure without a significant change.

More is not simply better. In the 22-trial meta-analysis, trials that reached 90 to 120 mmol of potassium a day lowered systolic pressure by 7.16 mm Hg, with a wide interval of 1.91 to 12.41, and the authors found no dose response. A later dose-response meta-analysis of 32 trials found a U-shaped curve. The benefit weakened once the extra potassium passed about 30 mmol a day, and blood pressure rose once it passed about 80 mmol. The authors caution that few trials tested high intakes.

Single trials show the same pattern at small scale. In 36 untreated adults with raised blood pressure on a fully controlled diet, 3 g of potassium a day for four weeks lowered 24-hour pressure by 3.9/1.6 mm Hg against placebo. In a one-week trial of 90 people with hypertension, 40 mmol of potassium chloride a day gave no extra reduction on top of cutting sodium, which lowered systolic pressure by 7 mm Hg. One week is shorter than the four-week minimum most meta-analyses use.

Unsettled. One review disagrees. A 2006 Cochrane review of 6 small trials in 483 hypertensive adults found a systolic fall of 11.2 mm Hg that did not reach statistical significance, with an interval from a rise of 2.7 to a fall of 25.2 and unexplained differences between trials. Its strict rules left only six trials, the larger later meta-analyses found a significant effect, and it has not been updated since 2006. The weight of evidence sits with the later reviews.

Salt substitutes

The strongest evidence on hard outcomes comes from salt that swaps part of the sodium chloride for potassium chloride. A Cochrane review found these substitutes lowered systolic pressure by 4.76 mm Hg and diastolic by 2.43 mm Hg against regular salt, on moderate-certainty evidence. A 2026 network meta-analysis of 34 trials in 37,063 adults found substitutes with 25 to 40 percent potassium chloride lowered systolic pressure by 4.39 to 4.64 mm Hg and meant 7 to 17 fewer deaths per 1000 people, on moderate to high certainty evidence. Most of that mortality benefit comes from one trial, SSaSS.

In SSaSS, 20,995 older adults in rural China with high blood pressure or a past stroke were randomized by village to a 25 percent potassium substitute or regular salt. Over 4.7 years, strokes ran at 29.14 against 33.65 per 1000 person-years, a rate ratio of 0.86 (95% CI 0.77 to 0.96). The substitute lowered sodium at the same time, so these results cannot be credited to potassium alone.

Who should be careful

Not for everyone. If your kidneys do not clear potassium well, extra potassium can push blood levels too high. The US National Institutes of Health notes that in chronic kidney disease, or with drugs such as ACE inhibitors or potassium-sparing diuretics, even dietary potassium below the Adequate Intake can cause hyperkalemia. The label of lisinopril, a common blood pressure drug, warns that potassium-sparing diuretics such as spironolactone, amiloride and triamterene raise the risk. If you take any of these, ask before using potassium supplements or a potassium salt substitute.

The reassuring safety data come from people chosen to be at low risk. In the Cochrane salt substitute review, blood potassium rose by 0.12 mmol/L, and hyperkalemia showed 4 more cases per 100,000 with an interval running from 47 fewer to 121 more, which includes no difference. Every trial in that review excluded people for whom extra potassium could be harmful. WHO likewise found little or no difference in hyperkalemia over up to five years, and says the reporting behind that result is unreliable. WHO's 2025 salt substitute advice does not apply to children, pregnant women, people with kidney impairment, or people taking potassium-sparing diuretics or potassium supplements. Those groups were left out of the trials, which is different from evidence of harm in them. The U-shaped curve above adds one more reason not to treat potassium tablets as the more the better, since in the dose-response meta-analysis the rise above about 80 mmol a day was seen in people on drug treatment for hypertension.

What expert bodies say

WHO strongly recommends more potassium from food to lower blood pressure in adults, and suggests at least 90 mmol (3,510 mg) a day. That guideline dates from 2012. The 2025 American high blood pressure guideline, as summarized by European Renal Best Practice, backs potassium-based salt substitutes (class 2A, level A) unless chronic kidney disease or another condition that raises potassium is present. The US Agency for Healthcare Research and Quality reviewed the trials in 2018 and found no evidence that raising potassium through food alone changes blood pressure in adults, based on four trials and low-strength evidence. That is an absence of trials more than a finding against food.

How we searched

What would change this answer

• A large, long randomized trial of potassium from food rather than tablets or salt substitutes, in adults with normal or untreated blood pressure, measured with 24-hour monitoring. The comparison of the same rise in 24-hour urinary potassium between people with and without hypertension rests on 10 trials in 684 people studied for one to six weeks.
• A trial that separates the potassium share of the salt substitute benefit from the sodium share. Until then the stroke and death results belong to the substitute, not to potassium.
• More trials at high intakes, to confirm or rule out the rise in blood pressure past about 80 mmol a day of extra potassium. We found no ongoing trial of either kind on ClinicalTrials.gov.

Sources

1. ev-kbp-01 · Meta-analysis or systematic review · systematic review and meta-analyses of RCTs and cohort studies · n = 1606
   Increased potassium intake reduced systolic blood pressure by 3.49 (95% confidence interval 1.82 to 5.15) mm Hg and diastolic blood pressure by 1.96 (0.86 to 3.06) mm Hg in adults, an effect seen in people with hypertension but not in those without hypertension.
   
   Who: adults in randomized controlled trials of increased potassium intake
   Effect: systolic -3.49 mm Hg (95% CI 1.82 to 5.15), diastolic -1.96 mm Hg (0.86 to 3.06); effect in hypertensive, not normotensive, adults
   Certainty: Basis of the WHO 2012 guideline. Mostly supplement trials of 4 weeks or more.
   BMJ, 2013 · checked 2026-10-06 · we read the abstract
2. ev-kbp-02 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs, subgroup analysis · n = —
   Systolic blood pressure was reduced by 7.16 (1.91 to 12.41) mm Hg when the higher potassium intake was 90-120 mmol/day, without any dose response.
   
   Who: adults in randomized controlled trials of increased potassium intake, subgroup by achieved intake
   Effect: systolic -7.16 mm Hg (95% CI 1.91 to 12.41) at 90-120 mmol/day (about 3500 to 4700 mg)
   Certainty: Subgroup; wide interval. 90 mmol/day is the WHO minimum for adults.
   BMJ, 2013 · checked 2026-10-06 · we read the abstract
3. ev-kbp-03 · Meta-analysis or systematic review · systematic review, meta-analysis and meta-regression of RCTs · n = 25 trials, 1163 participants
   Overall, potassium supplementation decreased systolic blood pressure of 4.48mmHg (95% CI 3.07-5.90) and diastolic blood pressure of 2.96mmHg (1.10-4.82).
   
   Who: hypertensive subjects in RCTs with potassium supplementation of at least 4 weeks
   Effect: systolic -4.48 mm Hg (95% CI 3.07 to 5.90), diastolic -2.96 mm Hg (1.10 to 4.82); larger with sodium of 4 g/day or more, low baseline potassium and no antihypertensive drugs
   Certainty: Trial count and N from the NIH ODS summary of this meta-analysis; mostly potassium chloride 30 to 120 mmol/day for 4 to 15 weeks.
   Int J Cardiol, 2017 · checked 2026-10-06 · we read the abstract
4. ev-kbp-04 · Meta-analysis or systematic review · dose-response meta-analysis of RCTs (one-stage cubic spline) · n = 32 trials
   We observed a U-shaped relationship between 24-hour active and control arm differences in potassium excretion and BP levels, with weakening of the BP reduction effect above differences of 30 mmol/d and a BP increase above differences ≈80 mmol/d.
   
   Who: mostly adults with hypertension in crossover trials of potassium supplementation (30 to 140 mmol/day), at least 4 weeks
   Effect: U-shaped curve: benefit weakens above a 30 mmol/day difference in potassium excretion, blood pressure increase above about 80 mmol/day; the rise seen in drug-treated hypertension
   Certainty: Authors caution that few trials tested high intakes. 30 mmol is about 1170 mg, 80 mmol about 3130 mg extra per day.
   J Am Heart Assoc, 2020 · checked 2026-10-06 · we read the abstract
5. ev-kbp-05 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 483
   CONCLUSIONS: This systematic review found no statistically significant effect of potassium supplementation on blood pressure.
   
   Who: adults with raised blood pressure in RCTs of oral potassium supplements, follow-up 8 to 16 weeks
   Effect: systolic -11.2 mm Hg (95% CI -25.2 to 2.7), not significant; unexplained heterogeneity
   Certainty: Strict inclusion (8 weeks or more, no drug changes) left only 6 trials; later larger meta-analyses found a significant effect. Not updated since 2006.
   Cochrane Database Syst Rev, 2006 · checked 2026-10-06 · we read the abstract
6. ev-kbp-06 · Meta-analysis or systematic review · systematic review and frequentist network meta-analysis of RCTs with GRADE · n = 37063
   Our results indicate that moderate-potassium and low-sodium salt substitutes (25-40% KCl, 60-79% NaCl) probably reduce all-cause mortality, cardiovascular mortality, non-fatal cardiovascular events and systolic blood pressure (SBP) compared to regular salt, with reductions of 7-17 deaths per 1000 individuals and 4.39-4.64 mmHg for SBP, based on moderate to high certainty evidence.
   
   Who: adults in randomized controlled trials comparing salt substitutes with regular salt, 15 countries, mean age 62.3
   Effect: SBP -4.39 to -4.64 mm Hg and 7 to 17 fewer deaths per 1000 with 25-40% KCl substitutes; moderate to high certainty (GRADE)
   Certainty: Mortality benefit driven by SSaSS; the substitute lowers sodium too, so the potassium share cannot be separated.
   BMC Med, 2026 · checked 2026-10-06 · we read the abstract
7. ev-kbp-07 · Randomized controlled trial(s) · open-label cluster-randomized trial · n = 20995
   The rate of stroke was lower with the salt substitute than with regular salt (29.14 events vs. 33.65 events per 1000 person-years; rate ratio, 0.86; 95% confidence interval [CI], 0.77 to 0.96; P = 0.006), as were the rates of major cardiovascular events (49.09 events vs. 56.29 events per 1000 person-years; rate ratio, 0.87; 95% CI, 0.80 to 0.94; P<0.001) and death (39.28 events vs. 44.61 events per 1000 person-years; rate ratio, 0.88; 95% CI, 0.82 to 0.95; P<0.001).
   
   Who: persons from 600 villages in rural China with a history of stroke or aged 60 or older with high blood pressure
   Effect: stroke 29.14 vs 33.65 per 1000 person-years, rate ratio 0.86 (95% CI 0.77 to 0.96)
   Certainty: Sodium was reduced at the same time; population with high discretionary salt use.
   N Engl J Med, 2021 · checked 2026-10-06 · we read the abstract
8. ev-kbp-08 · Randomized controlled trial(s) · randomized placebo-controlled crossover trial with fully controlled diet · n = 36
   During potassium supplementation, 24-h BP was significantly reduced by 3.9/1.6 mm Hg and central pulse pressure by 2.9 mm Hg.
   
   Who: untreated (pre)hypertensive individuals on a fully controlled diet relatively low in sodium and potassium
   Effect: 24-h BP -3.9/-1.6 mm Hg vs placebo; potassium excretion +63 mmol/24 h
   Certainty: Short (4 weeks per period), small; background diet low in sodium.
   J Hum Hypertens, 2015 · checked 2026-10-06 · we read the abstract
9. ev-kbp-09 · Randomized controlled trial(s) · double-blind randomized controlled factorial trial (sodium, potassium, nitrate) · n = 90
   BRJ with nitrate and potassium chloride supplements did not assist in decreasing BP during this short-time intervention.
   
   Who: participants with hypertension on a hand-out diet
   Effect: low-sodium groups SBP -7 mm Hg (95% CI -9 to -5); potassium chloride 40 mmol/day gave no additional reduction
   Certainty: One week only, which is shorter than the 4-week minimum of most meta-analyses.
   J Hum Hypertens, 2026 · checked 2026-10-06 · we read the abstract
10. ev-kbp-10 · Meta-analysis or systematic review · systematic review by a US federal agency with strength-of-evidence grading · n = 4 RCTs
    We did not find evidence to support an effect of increasing potassium through changes in food intake alone on BP in adults, based on four RCTs (low SoE).
    
    Who: adults in RCTs of increased potassium intake, AHRQ comparative effectiveness review
    Effect: no evidence that increasing potassium through food intake alone affects BP in adults (4 RCTs, low SoE)
    Certainty: Agency systematic review (T2 that can carry level A); search to 2017.
    AHRQ, 2018, Sodium and Potassium Intake: Effects on Chronic Disease Outcomes and Risks (Comparative Effectiveness Review 206) · checked 2026-10-06 · we read the section
11. ev-kbp-11 · Position of an expert body · WHO guideline (NUGAG, GRADE) · n = —
    WHO recommends an increase in potassium intake from food for reduction of blood pressure and risk of cardiovascular disease, stroke and coronary heart disease in adults (strong recommendation1 ).
    
    Who: adults and children, WHO guideline
    Effect: strong recommendation for food potassium; conditional recommendation of at least 90 mmol/day for adults
    Certainty: From 2012; differs from the US Adequate Intake (3400 mg men, 2600 mg women).
    WHO, 2012, Guideline: potassium intake for adults and children · checked 2026-10-06 · we read the section
12. ev-kbp-12 · Position of an expert body · expert commentary on a clinical practice guideline · n = —
    Reduction of dietary sodium intake below 2300 mg/day (Class I recommendation, Level A of evidence), or ideally below 1500 mg/day, use of potassium-based salt substitutes unless CKD or another potentially hyperkalemia-inducing condition is present (Class 2A recommendation, Level A of evidence), healthy diet [such as the Dietary Approaches to Stop Hypertension (DASH) diet], alcohol abstinence (Class I recommendation, Level A of evidence), physical activity (Class I recommendation, Level A of evidence)
    
    Who: adults, 2025 AHA/ACC multisociety high blood pressure guideline as summarized by European Renal Best Practice
    Effect: sodium below 2300 mg/day (class I) and potassium-based salt substitutes (class 2A, level A) except with CKD or hyperkalemia risk
    Certainty: Read through the ERBP commentary (full text in PMC); the guideline itself (40811516) is not in PMC.
    Nephrology Dialysis Transplantation, 2026, 2025 AHA/ACC/AANP/AAPA/ABC/ACCP/ACPM/AGS/AMA/ASPC/NMA/PCNA/SGIM guideline for the prevention, detection, evaluation and management of high blood pressure in adults: a commentary from the European Renal Best Practice (ERBP) · checked 2026-10-06 · we read the fulltext
13. ev-kbp-13 · Position of an expert body · agency fact sheet · n = —
    However, in people with impaired urinary potassium excretion due to chronic kidney disease or the use of certain medications, such as angiotensin converting enzyme (ACE) inhibitors or potassium-sparing diuretics, even dietary potassium intakes below the AI can cause hyperkalemia [11].
    
    Who: people with impaired urinary potassium excretion
    Effect: no UL set; hyperkalemia risk below the AI with CKD, ACE inhibitors or potassium-sparing diuretics
    Certainty: Position; the reason blood pressure patients on these drugs should ask before using supplements or salt substitutes.
    NIH Office of Dietary Supplements, Potassium Fact Sheet for Health Professionals · checked 2026-10-06 · we read the section
14. ev-kbp-14 · Position of an expert body · WHO guideline · n = —
    The recommendation in this guideline is intended for adults in the general population and excludes individuals with kidney impairments or with other circumstances or conditions that might compromise potassium excretion (e.g. those taking potassium-sparing diuretics and potassium supplements). The recommendation does not apply to children or pregnant women.
    
    Who: adults in general populations, WHO guideline on lower-sodium salt substitutes
    Effect: conditional recommendation for adults; excluded groups listed
    Certainty: Exclusions reflect who was left out of the trials, not proven harm.
    WHO, 2025, Use of lower-sodium salt substitutes: WHO guideline summary · checked 2026-10-06 · we read the section
15. ev-kbp-15 · Position of an expert body · FDA-approved drug label · n = —
    Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) can increase the risk of hyperkalemia.
    
    Who: patients taking lisinopril
    Effect: hyperkalemia risk with potassium-sparing diuretics
    Certainty: Label text; ACE inhibitor and ARB labels carry similar wording on potassium supplements and salt substitutes.
    Lisinopril tablets, FDA-approved label (DailyMed), effective 2023-08-18 · checked 2026-10-06 · we read the section
16. k-t1 · Meta-analysis or systematic review · systematic review and pairwise meta-analysis of placebo-controlled randomized trials of six supplements · n = six supplements compared with placebo across the included randomized trials
    Calcium and magnesium achieved significant reductions in both SBP and DBP of -1.37/-1.63 mm Hg and -2.79/-1.56 mm Hg, respectively. Vitamin E and potassium only yielded significant reductions in SBP with values of -1.76 mm Hg and -2.10 mm Hg, respectively.
    
    Who: adults of the general, normotensive population, potassium arm of a six-supplement review
    Effect: systolic blood pressure -2.10 mm Hg against placebo; diastolic blood pressure not significantly reduced by potassium
    Certainty: the same review found calcium and magnesium lowered both systolic and diastolic pressure, while vitamins C and D lowered neither; optimal dose and treatment length were left undetermined
    Behers et al., Nutrients, 2023 · checked 2026-09-17 · we read the abstract
17. k-t3 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of randomized and cluster-randomized trials · n = 34,961 adults and 92 children randomized; 21,414 participants in the systolic analysis
    LSSS compared to regular salt probably reduce DBP on average (mean difference (MD) -2.43 mmHg, 95% confidence interval (CI) -3.50 to -1.36; 20,830 participants, 19 RCTs, moderate-certainty evidence) and SBP (MD -4.76 mmHg, 95% CI -6.01 to -3.50; 21,414 participants, 20 RCTs, moderate-certainty evidence) slightly.
    
    Who: adults in 26 trials, 11 of them in people with hypertension, 11 mixed, one in normotensive and one in pre-hypertensive participants; 14 of 26 trials in low- and middle-income countries
    Effect: systolic blood pressure -4.76 mm Hg (95% CI -6.01 to -3.50, 20 trials) and diastolic -2.43 mm Hg (95% CI -3.50 to -1.36, 19 trials) against regular salt
    Certainty: moderate-certainty evidence for both; every included trial specifically excluded people for whom extra potassium could be harmful, so this says nothing about kidney disease or potassium-retaining drugs
    Brand et al., Cochrane Database of Systematic Reviews, 2022 · checked 2026-09-17 · we read the abstract
18. k-t4 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of randomized and cluster-randomized trials, safety outcomes · n = 784 participants in 6 trials for blood potassium, 22,849 in 5 trials for hyperkalemia
    probably increase blood potassium slightly (MD 0.12 mmol/L, 95% CI 0.07 to 0.18; 784 participants, 6 RCTs, moderate-certainty evidence), compared to regular salt. LSSS may result in little to no difference, on average, in hypertension (AE 17 fewer/1000, 95% CI -58 to 17; 2566 participants, 1 RCT, low-certainty evidence) and hyperkalaemia (AE 4 more/100,000, 95% CI -47 to 121; 22,849 participants, 5 RCTs, moderate-certainty evidence) compared to regular salt.
    
    Who: adults in the same 26 trials, all of which excluded people at known risk from extra potassium
    Effect: blood potassium +0.12 mmol/L (95% CI 0.07 to 0.18); hyperkalemia 4 more cases per 100,000 (95% CI -47 to 121), a confidence interval that spans no effect
    Certainty: moderate-certainty evidence for both, but the safety signal cannot be transferred to chronic kidney disease, ACE inhibitors, ARBs or potassium-sparing diuretics, since those people were excluded by design
    Brand et al., Cochrane Database of Systematic Reviews, 2022 · checked 2026-09-17 · we read the abstract
19. k-e3-10 · Position of an expert body · systematic review commissioned for a WHO guideline, with GRADE assessment of certainty · n = number of included trials in this section not stated
    The systematic review found no meaningful increase in hyperkalaemia with LSSS when compared to regular salt, with little or no difference in effect for this important safety outcome at maximal follow-up of 5 years.
    
    Who: randomized trials of lower sodium salt substitutes in adults
    Effect: little or no difference in hyperkalemia between salt substitute and regular salt at maximal follow-up of five years
    Certainty: the same review says this evidence is weak: few trials reported the outcome, they defined it differently, and the reviewers call the information unreliable. A null result built on unreliable reporting is not a safety guarantee
    Use of lower-sodium salt substitutes: WHO guideline, World Health Organization, 2025 (CC BY-NC-SA 3.0 IGO) · checked 2026-09-18 · we read the section
20. k-e3-14 · Meta-analysis or systematic review · dose-response meta-analysis of randomized controlled trials pooled from three systematic reviews, with potassium intake measured as 24-hour urinary excretion rather than reported intake · n = 10 trials, 684 patients
    For instance, for a 50 mmol/day increase in 24-h urinary potassium excretion the hypotensive effect was estimated at –5.3 mmHg in SBP in subjects with hypertension compared with only –0.5 mmHg in subjects without hypertension
    
    Who: 684 adults in 10 randomized trials published between 2005 and 2021, in the UK, USA, Italy, China, the Netherlands and Denmark. Six groups had hypertension, four did not
    Effect: for a 50 mmol per day rise in 24-hour urinary potassium, systolic pressure fell 5.3 mmHg with hypertension against 0.5 mmHg without, and diastolic 3.6 against 0.1 mmHg. The linear relationship reached significance only in the hypertensive group (P = .02 against P = .48)
    Certainty: the trials lasted one to six weeks and total 684 people, which is small for a dose-response curve, and the two subgroups were also given different ranges of extra potassium, so the comparison between them is not a like for like contrast. This article is newer than our corpus snapshot and was found by the web pass
    Clinical Kidney Journal, 2025 · checked 2026-09-18 · we read the fulltext
21. k-e3-15 · Meta-analysis or systematic review · dose-response meta-analysis, characteristics of the included evidence base · n = 10 trials, 684 patients, 342 per arm
    The studies involved a total of 684 patients, 342 in the intervention group (potassium intake modification) and 342 in the control group (unchanged potassium intake). ... Intervention durations ranged from 1 to 6 weeks.
    
    Who: the 10 randomized trials that survived selection out of 1826 identified references
    Effect: intervention durations of one to six weeks, mean ages 26 to 66, most trials crossover, eight of ten using ambulatory blood pressure monitoring
    Certainty: this counts the trials that measured potassium by 24-hour urine, which is the strict way to do it and also the reason the pool is small. Larger bodies of evidence exist for salt substitutes and for observational intake
    Clinical Kidney Journal, 2025 · checked 2026-09-18 · we read the fulltext