Potassium

Does potassium lower blood pressure?

Updated 9 Nov 2026

Short answer

Yes, in people with high blood pressure, by a few mmHg. A 2017 review of 25 trials found 4.48 mmHg lower systolic and 2.96 mmHg lower diastolic pressure.[1][2] In people with normal blood pressure, reviews found no clear effect.[3][2]

What the reviews found

In the 2017 review, the trials lasted 4 weeks or more and mostly gave potassium chloride.[2][1]

  • 2017 review, people with high blood pressure. 25 trials with 1,163 people took 30 to 120 mmol a day (1,173 to 4,692 mg) for 4 to 15 weeks. Systolic pressure fell by 4.48 mmHg and diastolic pressure by 2.96 mmHg.[1][2]
  • 2013 review in the BMJ. In 22 trials with 1,606 people, systolic pressure fell by 3.49 mmHg and diastolic pressure by 1.96 mmHg. The effect was seen in people with high blood pressure, but not in people with normal blood pressure. At 90 to 120 mmol a day, systolic pressure fell by 7.16 mmHg.[3]
  • US National Academies (NASEM). In 16 trials, systolic pressure fell by 6.87 mmHg and diastolic pressure by 3.57 mmHg. In trials of people without high blood pressure only, the drop was not statistically significant.[2]
  • 2006 Cochrane review. Only 6 trials with 483 people met its rules. The drop was large but not statistically significant, and the authors called the evidence not conclusive.[4] Later reviews with more trials found a clear effect.[1][3]

Who gains the most

In the 2017 review, blood pressure fell more in people who ate less than 90 mmol of potassium a day before the trial. It also fell more in people who ate 4 g of sodium a day or more, and in people who took no blood pressure medicine.[1] The effect may be largest in people whose blood pressure reacts strongly to salt.[2]

More is not always better

A 2020 review of 32 trials looked at the dose, measured as the extra potassium in urine compared with the control group. Above about 30 mmol a day of extra potassium, blood pressure fell less. Above about 80 mmol a day of extra potassium, blood pressure started to rise again.[5] This rise was seen in people treated with blood pressure medicines, not in untreated people. The authors say that few trials tested high doses, so these estimates need caution.[5]

Salt substitutes

Salt substitutes replace part of the sodium chloride in salt with potassium chloride.[2] In a 2022 Cochrane review, systolic pressure was 4.76 mmHg lower than with regular salt in 20 trials with 21,414 adults. Diastolic pressure was 2.43 mmHg lower in 19 trials. The certainty was moderate.[6] Part of this effect may come from eating less sodium, not from more potassium.[2]

Why it may work

  1. Potassium makes the kidneys pass more sodium into urine.[2]
  2. With less sodium, the volume of blood plasma goes down.[2]
  3. Potassium also widens blood vessels.[2]

Who should be careful

People with kidney disease, or who take ACE inhibitors, angiotensin receptor blockers (ARBs) or potassium-sparing diuretics, can develop high blood potassium (hyperkalemia), even from food.[2] Anyone who takes a blood pressure medicine should talk with a doctor or pharmacist about potassium intake.[2]

What is still unknown

NASEM found the evidence too weak to set an intake that lowers the risk of chronic disease.[2] The 2020 review asks for caution with high doses, because few trials tested them.[5]

Sources (6)

  1. The effect of potassium supplementation on blood pressure in hypertensive subjects: A systematic review and meta-analysis. Filippini T, Violi F, D'Amico R, Vinceti M Int J Cardiol, 2017. PMID 28024910
  2. Potassium: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  3. Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses. Aburto NJ, Hanson S, Gutierrez H, Hooper L, Elliott P, Cappuccio FP BMJ, 2013. PMID 23558164
  4. Potassium supplementation for the management of primary hypertension in adults. Dickinson HO, Nicolson DJ, Campbell F, Beyer FR, Mason J Cochrane Database Syst Rev, 2006. PMID 16856053
  5. Potassium Intake and Blood Pressure: A Dose-Response Meta-Analysis of Randomized Controlled Trials. Filippini T, Naska A, Kasdagli MI, Torres D, Lopes C, Carvalho C, et al. J Am Heart Assoc, 2020. PMID 32500831
  6. Replacing salt with low-sodium salt substitutes (LSSS) for cardiovascular health in adults, children and pregnant women. Brand A, Visser ME, Schoonees A, Naude CE Cochrane Database Syst Rev, 2022. PMID 35944931

More about potassium

What is potassium?Which foods contain potassium?What is potassium used for?What happens if you do not get enough potassium?Is potassium safe?Why do potassium supplements contain only 99 mg?

For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.