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Supplement

Potassium

Mineral · potassium chloride, potassium citrate, potassium gluconate, potassium bicarbonate

Potassium is the counterpart of sodium and one of the most effective levers on blood pressure that diet offers. Most people take in less than the WHO recommends. The most convincing data, however, come not from tablets but from potassium-containing salt and potassium-rich food.

In short

Potassium lowers blood pressure in people with hypertension, by 3.49 mmHg systolic in a meta-analysis for the WHO. In the SSaSS trial with 20,995 participants, a salt substitute with 25 percent potassium chloride reduced strokes, cardiovascular events and deaths over a mean of 4.74 years. The WHO recommends at least 3,510 mg per day for adults, ideally from vegetables, legumes, nuts and fruit. The catch: in kidney disease or with certain blood pressure medicines, too much potassium can become dangerous. The BfR proposes a maximum of 500 mg per daily dose for food supplements.

What it is

Potassium is a mineral that nerves and muscles need to do their work. The EU permits the claims that potassium contributes to normal functioning of the nervous system, to normal muscle function and to the maintenance of normal blood pressure.

The D-A-CH societies estimate the requirement at 4,000 mg per day from the age of 15, EFSA at 3,500 mg, derived from data on blood pressure and stroke. According to the German National Nutrition Survey, women reach a median of 2,825 to 3,254 mg, men 3,374 to 3,807 mg. So many fall below this. The WHO notes that most people take in too much sodium and too little potassium.

How it works

Potassium and sodium work as counterparts. That is why potassium works above all where a lot of salt is eaten and blood pressure is elevated. A dose-response analysis of 32 studies showed exactly that: the reduction in blood pressure was greatest with hypertension and high sodium intake. The WHO also considers the two together and recommends taking in less sodium and more potassium.

Where potassium is found

The WHO lists beans and peas with about 1,300 mg per 100 g, nuts with about 600 mg, spinach, cabbage and parsley with about 550 mg, and bananas, papaya and dates with about 300 mg. According to the NIH, a baked potato provides 610 mg, a banana 422 mg, a cup of cooked lentils 731 mg. Processing lowers the potassium content. People who eat a lot of convenience food therefore often take in too much sodium and too little potassium.

Supplements contain potassium chloride, citrate, gluconate or bicarbonate. Potassium gluconate is about 94 percent absorbed, similar to potassium from potatoes. Depending on the brand, salt substitute products provide about 440 to 2,800 mg of potassium per teaspoon.

Potassium citrate and kidney stones

Potassium citrate plays a special role. Citrate binds calcium in the urine and so slows the formation of crystals. A Cochrane review pooled 7 studies with 477 participants, who mostly had calcium oxalate stones and were treated for at least 6 months. With citrate salts, new stones formed much less often, and existing stones more often became smaller. The reporting quality of the studies, however, was moderate to poor. In another study, 30 to 60 mEq of potassium citrate over 3 years reduced stone formation compared with placebo. This is a physician-directed treatment, not an everyday supplement.

What is well supported

For blood pressure, the data are broad. The meta-analysis by Aburto and colleagues for the WHO guideline included 22 randomized trials with 1,606 participants: more potassium lowered blood pressure by 3.49 over 1.96 mmHg, and at a higher intake of 90 to 120 mmol per day even by 7.16 mmHg systolic. Kidney function and blood lipids were not adversely affected. The authors rate this as high-quality evidence. In cohort studies with 127,038 people, higher potassium intake was associated with 24 percent fewer strokes. The evidence from salt substitute research is particularly strong because it provides hard endpoints. A meta-analysis of 21 studies with 31,949 participants found that potassium-containing salt substitute lowered blood pressure in all regions and groups and reduced all-cause mortality to a relative risk of 0.89, cardiovascular deaths to 0.87 and cardiovascular events to 0.89. For kidney stones, according to Cochrane, citrate salts such as potassium citrate prevent new stones, with a relative risk of 0.26.

What the studies show

SSaSS: salt substitute against stroke

In 600 villages in rural China, 20,995 people with a history of stroke or aged 60 and over with hypertension replaced their table salt with a mixture of 75 percent sodium chloride and 25 percent potassium chloride, or stayed with normal salt. After a mean of 4.74 years, there were 29.14 instead of 33.65 strokes per 1,000 person-years, a rate ratio of 0.86. Major cardiovascular events and deaths also declined. Serious hyperkalemia did not occur significantly more often, 3.35 versus 3.30 per 1,000 person-years.

The meta-analysis for the WHO

Aburto and colleagues analysed 22 randomized trials and 11 cohort studies. Blood pressure fell markedly in people with hypertension, but not in people with normal blood pressure. In the cohorts, higher potassium intake was associated with a relative stroke risk of 0.76. On this basis, the WHO has recommended at least 3,510 mg of potassium per day since 2013.

How much is enough?

Filippini and colleagues examined 32 studies, most of which gave 30 to 140 mmol of potassium per day as a supplement. The relationship was U-shaped: above an additional amount of about 30 mmol per day, the reduction in blood pressure no longer increased, and above about 80 mmol, blood pressure even rose again in people who were already taking blood pressure medication. The authors therefore advise against excessive supplementation.

Where the data stop

With normal blood pressure, the WHO meta-analysis found no significant effect, and in children the reduction of 0.28 mmHg was likewise not significant. For cardiovascular disease overall and coronary heart disease, too, the associations in the cohorts were not significant, unlike for stroke. The hard endpoints from SSaSS apply to a salt substitute that lowers sodium at the same time. Which share is due to more potassium and which to less sodium cannot be separated. The trial was open-label, and it ran in high-risk patients in rural China with high salt consumption. There are no comparable endpoint studies for potassium tablets. The supplement studies evaluated by the BfR mostly lasted 2 to 24 weeks. And more is not better: the U-shaped dose-response argues for closing the gap to the recommended intake, not going beyond it. On muscle cramps, there are no reliable figures from controlled studies with potassium preparations.

Status, approval and legal

Potassium is an authorized mineral for food supplements. EFSA was unable to derive a tolerable upper intake level. The BfR proposes 500 mg per daily dose of a preparation and, based on current knowledge, considers an additional intake of up to 3,000 mg per day to be unproblematic for healthy adults. Potassium chloride as a table salt substitute is not affected by this. In the US, over-the-counter potassium preparations are usually limited to 99 mg. Potassium is not on the WADA Prohibited List for 2026.

Safety

With healthy kidneys, the body regulates the potassium level tightly; according to EFSA, the risk from potassium in food is low even at 5,000 to 6,000 mg per day. It becomes dangerous when excretion is impaired. This affects people with chronic kidney disease and people taking ACE inhibitors, sartans or potassium-sparing diuretics, as well as people with type 1 diabetes. Too much potassium in the blood can disturb heart function; case reports describe such effects after 5,000 to 7,000 mg from supplements. Potassium chloride tablets can irritate the mucosa of the gastrointestinal tract; in the US they have been linked to small-intestine damage. The British Expert Group on Vitamins and Minerals saw no obvious harm at 3,700 mg per day from supplements, but warned that certain preparations can injure the mucosa even below that. Conversely, people on loop or thiazide diuretics lose more potassium. Anyone taking blood pressure medication or diuretics or who has kidney disease should use neither potassium preparations nor potassium salt substitute without consulting a physician.

BK-Score Well supported

Human evidence8
Mechanism8
Safety data8
Hype gap7
Track record of use10

The blood pressure effect is consistently supported: 22 RCTs with 1,606 participants showed −3.49/−1.96 mmHg in hypertension, without harm to kidney function or blood lipids (BMJ 2013); cohorts with 127,038 people link higher intake with 24 % fewer strokes. The salt substitute provides hard endpoints: in SSaSS with 20,995 high-risk participants, salt with 25 % potassium chloride reduced strokes (0.86), major cardiovascular events (0.87) and deaths (0.88) over 4.74 years without significantly more serious hyperkalemia (N Engl J Med 2021); a meta-analysis of 21 studies confirms this. Limitations: the salt substitute lowers sodium at the same time, endpoint studies are lacking for potassium tablets, and the dose-response is U-shaped (J Am Heart Assoc 2020). With impaired kidney function or potassium-sparing medication, hyperkalemia is the central risk.

The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)

Frequently asked questions about potassium

How much potassium do you need per day?

The WHO recommends at least 3,510 mg per day for adults, EFSA sets 3,500 mg, the D-A-CH societies 4,000 mg. Many people in Germany fall below this at the median, especially women.

Does potassium lower blood pressure?

Yes, in people with hypertension. In a meta-analysis, the systolic value fell by 3.49 mmHg, and by 7.16 mmHg at a higher intake of 90 to 120 mmol per day. With normal blood pressure, no significant effect could be shown.

Which foods contain a lot of potassium?

According to the WHO, legumes such as beans and peas provide about 1,300 mg per 100 g, nuts about 600 mg, spinach and cabbage about 550 mg. Potatoes, dried fruit and bananas are also good sources. Processing lowers the content.

Does a potassium salt substitute make sense?

In a large trial, a salt substitute with 25 percent potassium chloride reduced strokes and deaths in high-risk patients. Anyone with kidney disease or taking potassium-sparing medication should, however, use it only after consulting a physician.

Can you take too much potassium?

With healthy kidneys, hardly through food. In kidney disease or with ACE inhibitors, sartans and potassium-sparing diuretics, the blood level can rise dangerously and disturb heart function. The BfR proposes a maximum of 500 mg per daily dose for food supplements.

Does potassium help with muscle cramps?

Potassium contributes to normal muscle function; that is an authorized claim. But there are no controlled studies showing that potassium preparations prevent muscle cramps. Frequent cramps should be checked by a physician.

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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-09-26.