Potassium salt substitutes
Potassium-enriched salt substitutes are table salt with part of the sodium chloride swapped for potassium chloride. They lower blood pressure a little, and in one large trial in rural China they cut strokes and deaths, but that hard-outcome evidence comes almost entirely from China and Taiwan, and the extra potassium can be dangerous for people whose kidneys can't clear it.
If you have high blood pressure or are at risk of it, a potassium salt substitute is a reasonable swap for the salt you add at home. Don't use one if you have chronic kidney disease or take a drug that holds on to potassium, such as a potassium-sparing diuretic, unless your blood potassium is checked first.
What it is
A typical substitute replaces roughly a quarter to a little under a third of the sodium chloride with potassium chloride. The 2025 American blood-pressure guideline rates substitutes as reasonable rather than essential (its second-strongest tier) and puts the expected effect at about 5/1.5 mm Hg.[1]
The big trial: fewer strokes in rural China
The Salt Substitute and Stroke Study randomised 600 rural Chinese villages, 20,995 people with an average age of 65, to a salt that was three-quarters sodium chloride and one-quarter potassium chloride, or to ordinary salt. Most were high-risk: 73% had survived a stroke and 88% already knew they had hypertension. Over nearly five years (a mean of 4.74), strokes ran at about 29 per 1,000 person-years on the substitute against about 34 on regular salt, roughly 14% fewer. Major cardiovascular events and deaths from any cause fell by similar amounts, and serious high blood potassium did not increase.[2]
How far it applies
A 2024 review of 16 randomised trials found that the evidence on strokes, heart attacks and deaths comes almost entirely from China and Taiwan, mostly in older or higher-risk people. It graded the survival benefit low certainty and the fall in cardiovascular events very low.[3]
Where the salt goes matters too. Substitutes help most where salt is added at home. Where most sodium already arrives in packaged and restaurant food, changing what is in the shaker moves a smaller share of the total.
Who should not use them
The potassium is the point and the risk. The guideline excludes people with chronic kidney disease and anyone taking a drug that reduces potassium excretion, such as a potassium-sparing diuretic, unless their blood potassium is monitored first.[4]
What to do
- Cut packaged and restaurant food first; that is where most sodium comes from. See Salt.
- Then swap the salt you cook and season with for a potassium-enriched one, if you have or are at risk of high blood pressure.
- Don't use one if you have kidney disease or take a potassium-sparing diuretic or another drug that holds on to potassium, unless your blood potassium is checked first. The wider blood-pressure plan is in Blood pressure.