PotassiumMineral

• Blood pressure in adults who already have hypertensionPossibly helps

  NIH's Office of Dietary Supplements reports that most clinical trials show a reduction [2].
  
  A 2017 meta-analysis of 25 RCTs in 1,163 hypertensive adults found systolic pressure fell 4.48 mmHg and diastolic 2.96 mmHg on 30–120 mmol/day, mostly potassium chloride [2].
  
  A second meta-analysis of 15 trials found similar reductions, again concentrated in people who already had hypertension [2]. The FDA allows a qualified health claim that potassium-rich, low-sodium diets may reduce the risk of high blood pressure and stroke [2]. ^[2]

• The blood-pressure literature is not unanimousPossibly helps

  A Cochrane Review of the six highest-quality trials found the blood-pressure reduction was not statistically significant [2].
  
  A 2018 AHRQ systematic review found dietary potassium's link to blood pressure inconsistent across observational studies. Its own trial analysis still found supplemental potassium at 20–120 mmol/day, over 1–36 months, lowered blood pressure versus placebo [2].
  
  We are not resolving that for you. The same literature reads differently depending on how strictly the trials are filtered. ^[2]

• Salt substitutes — how much of the effect is potassium?Possibly helps

  AHRQ found potassium-containing salt substitutes lowered blood pressure, then found that sodium reduction alone accounted for the benefit [2].
  
  Adding potassium via food or supplements on top did not lower blood pressure any further. Some of potassium's apparent effect in salt-substitute studies may really be a sodium-reduction effect [2]. ^[2]

• Stroke risk — cohort data onlyPossibly helps

  Across 11 prospective cohort studies (247,510 adults), each 1,640 mg/day higher potassium intake tracked with 21% lower stroke risk [2].
  
  A separate meta-analysis of 16 cohorts (639,440 participants) found 15% lower stroke risk in the highest- versus lowest-intake groups [2].
  
  Adjusting for blood pressure still left a significant 13% reduction, which hints at mechanisms beyond blood pressure. These are observational studies — association, not demonstrated cause [2]. ^[2]

• Exercise-associated muscle crampsNot shown to help

  A 2022 evidence-based sports-medicine review states potassium is "generally not considered an electrolyte of interest" for exercise-associated muscle cramps [25].
  
  Dehydrated athletes who ate one or two servings of banana after exercise showed no rise in blood potassium until 60 minutes later [25].
  
  A clinical-perspective review adds that potassium-rich foods and supplements have not shown an effect on cramp symptoms in controlled research [25]. Sweat potassium losses are small next to sodium losses during exercise. ^[25]

• Low blood potassium, under prescriptionLikely helps

  Slow- and extended-release potassium chloride tablets and capsules are used medically for hypokalemia, particularly in patients on potassium-wasting diuretics [2].
  
  That is a prescription drug use with FDA-approved labelling behind it — a different thing from a 99 mg supplement [15].
  
  The same labelling contraindicates these products where the GI tract is narrowed structurally or pathologically [15]. ^[15]

• Mild (serum 3.0–3.5 mEq/L) is often silent, or shows as fatigue, muscle weakness, cramping, constipation and malaise [8][2]
• Moderate to severe (below about 2.5 mEq/L): polyuria, muscular paralysis, glucose intolerance, cardiac arrhythmias — especially with underlying heart disease [8][2]
• Heart palpitations appear among the milder-case symptoms in Cleveland Clinic's listing [11]
• ECG changes run in a set order: ST-segment sagging, T-wave flattening then inversion, then a prominent U wave [10]
• Further worsening brings prolonged QT/QU, premature contractions, atrial fibrillation, supraventricular tachycardia, torsades de pointes, ventricular fibrillation and cardiac arrest [10]
• Cardiac effects stay minimal until serum potassium falls below about 3 mEq/L, per the Merck Manual [10]
• The blood number understates the shortfall — roughly 100 mmol of total-body potassium is gone per 0.3 mmol/L drop in serum [9]
• More than half of people with clinically significant hypokalemia also have magnesium deficiency, which raises arrhythmia risk further; both need correcting together [2]
• Up to 21% of hospitalized patients have hypokalemia [2]
• Source disagreement: StatPearls bands severity as 3.0–3.5 / 2.5–3.0 / below 2.5 mEq/L, while NIH ODS gives no separate mild band [8][2]^[2]

• Potassium chloride (KCl)The form used in most blood-pressure trials, at 30–120 mmol/day

  Elemental content

  The chloride salt — the most common form in both supplements and salt substitutes [2]

  Absorption

  A 2025 systematic review of RCTs in healthy adults found good bioavailability regardless of dose or route [12].
  
  Liquid KCl is absorbed within a few hours. Enteric-coated tablets bypass stomach dissolution and absorb more slowly [2].

  Best for

  The form used in most blood-pressure trials, at 30–120 mmol/day [2]

• Potassium citrateAn alternative when the chloride load isn't wanted.

  Elemental content

  The citrate salt; citrate is also one of the forms potassium naturally takes in fruit and vegetables [2]

  Absorption

  The same 2025 review found chloride and citrate both well absorbed in healthy adults [12].
  
  An earlier trial found potassium-magnesium citrate delivered potassium as well as citrate or chloride alone did [13].

  Best for

  An alternative when the chloride load isn't wanted. NIH ODS says no single form is clearly superior for general use [2]

• Potassium gluconateCommon in consumer capsules, at the usual 99 mg per serving

  Elemental content

  The gluconate salt [2]

  Absorption

  A 2016 dose-response trial measured about 94% absorption, close to potassium's absorption from potatoes [2].
  
  Dietary potassium overall runs about 85–90% absorbed [2].

  Best for

  Common in consumer capsules, at the usual 99 mg per serving [2]

• Extended-release potassium chloride (prescription)Prescription use for hypokalemia, especially on potassium-wasting diuretics.

  Elemental content

  Drug-strength KCl, far above the 99 mg a supplement carries [15]

  Absorption

  Formulated to release along the gut rather than dissolve all at once [2].
  
  Controlled-release KCl has been linked to esophageal and small-bowel ulceration. FDA labelling advises liquid potassium instead where the esophagus is compressed, as by an enlarged left atrium [15].

  Best for

  Prescription use for hypokalemia, especially on potassium-wasting diuretics. Contraindicated where the GI tract is narrowed [15]

• Potassium inside a multivitaminNot much. A multivitamin is not designed to be a meaningful potassium source

  Elemental content

  Typically about 80 mg per serving in products that include it at all [2]

  Absorption

  Absorption isn't the constraint here; the amount is [2].
  
  At 80 mg it sits near 2% of the FDA Daily Value [2].

  Best for

  Not much. A multivitamin is not designed to be a meaningful potassium source [2]

• Salt substitutesCutting sodium at the table. Not for people with kidney disease or on ACE inhibitors, ARBs or potassium-sparing diureti…

  Elemental content

  Mostly potassium chloride standing in for some or all sodium chloride — 440 to 2,800 mg potassium per teaspoon depending on product [2]

  Absorption

  Absorbed like any other potassium chloride [2].
  
  A teaspoon can carry many times a 99 mg supplement's dose, which is why the kidney and drug cautions below apply to it [2].

  Best for

  Cutting sodium at the table. Not for people with kidney disease or on ACE inhibitors, ARBs or potassium-sparing diuretics [2]

• GI bleeding and ulceration from solid potassium chloride

  WebMD's pharmacist-reviewed monograph and an FDA drug label both describe gastrointestinal bleeding, ulceration and — rarely — intestinal narrowing, obstruction or perforation with solid-dose potassium chloride [14][15].
  
  Risk runs higher with a history of stomach ulcers, or on anticholinergic medications [14].
  
  The FDA label ties this specifically to controlled-release KCl products, and advises liquid potassium where esophageal compression is a concern [15]. ^[15]

• Kidney disease and impaired excretion

  People with chronic kidney disease and impaired potassium excretion can develop hyperkalemia at ordinary dietary intakes, no supplement required [2].
  
  FDA labelling lists renal failure as a contraindication for potassium chloride supplementation [15]. The NASEM Adequate Intakes on this page explicitly do not apply to this group [2]. ^[2]

• Other conditions that raise hyperkalemia risk

  Hyperkalemia can also arise in type 1 diabetes, congestive heart failure, adrenal insufficiency including untreated Addison disease, and liver disease [2]. ^[2]

• Pregnancy and breastfeeding

  Potassium requirements rise in pregnancy and lactation, and potassium is a normal component of breast milk [2].
  
  WebMD's monograph states that how potassium supplements specifically affect pregnancy or a fetus is not established, and advises asking a provider first [14].
  
  Drugs.com adds that pregnancy slows GI motility, so solid oral forms warrant close serum monitoring. Supplementation that avoids hyperkalemia is not expected to harm the fetus [24]. ^[14]

• ACE inhibitors and ARBs

  Benazepril (Lotensin), losartan (Cozaar) and their class-mates — used for hypertension, heart failure and chronic kidney disease — reduce urinary potassium excretion [2].
  
  Add supplemental potassium and blood levels can climb into hyperkalemia, which is more likely and more dangerous when kidney function is already impaired.
  
  NIH's ODS advises monitoring potassium status in patients taking these drugs [2]. ^[2]

• Potassium-sparing diuretics

  Amiloride (Midamor) and spironolactone (Aldactone) work by reducing how much potassium the urine carries away [2].
  
  A potassium supplement or a potassium-based salt substitute pushes in the same direction, raising hyperkalemia risk [2]. ^[2]

• Loop and thiazide diuretics — the opposite direction

  Furosemide (Lasix), bumetanide (Bumex), chlorothiazide (Diuril) and metolazone (Zaroxolyn) increase urinary potassium losses and can cause hypokalemia [2].
  
  That is why a clinician sometimes adds potassium alongside them. It's a supervised decision, not a self-serve one [2]. ^[2]

Potassium is spread across plant and animal foods, and the body absorbs an estimated 85–90% of what arrives in the diet [2].

Highest per-serving common sources, per NIH's ODS using USDA FoodData Central: dried apricots (1/2 cup) 755 mg, cooked lentils (1 cup) 731 mg, baked potato flesh (1 medium) 610 mg [2].

Then orange juice (1 cup) 496 mg, banana (1 medium) 422 mg, grilled chicken breast (3 oz) 332 mg [2]. Harvard Health adds cooked spinach (1/2 cup) at 419 mg and a whole russet potato baked with skin at 952 mg [16].

Whole-wheat flour and brown rice carry considerably more than their refined counterparts [2]. Australia's healthdirect service lists a similar spread of fruit, vegetables, legumes and dairy [17].

The potassium in produce arrives as phosphate, sulfate, citrate and other salts. That is chemically not the same thing as the potassium chloride in salt substitutes and most supplements [2].

No hour of the day is medically mandated. What pharmacist and drug-label sources do agree on is taking it with food or right after a meal, with a full glass of water [18][15].

Potassium chloride on an empty stomach can irritate the stomach lining, causing nausea, stomach pain or diarrhea [18].

Extended-release capsules and tablets are to be swallowed whole — never crushed or chewed [15]. They can cause drug-induced esophagitis, so staying upright afterwards and washing the dose down with plenty of liquid both matter [15].

SingleCare's pharmacist-reviewed piece notes some people feel more alert after a dose and prefer it earlier in the day. It frames that as individual preference, not a rule, and twice-daily schedules usually land at breakfast and dinner [18].

The same source calls the "potassium is sedating" idea a misconception. Unlike magnesium, it has no established sleep-promoting effect [18].