Potassium is an important electrolyte and mineral present in all of your cells. Your body usually naturally balances your potassium levels, but certain people may need supplements. And knowing the best form of potassium for your health needs can help you reap all the benefits of the mineral.
Potassium helps regulate your body's electrical currents — like those involved in muscle contractions and your heartbeat — and can help lower your risk for cardiovascular problems and other ailments, says Jerlyn Jones, MS, RDN, spokesperson for the Academy of Nutrition and Dietetics and owner of The Lifestyle Dietitian in Atlanta.
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But according to the 2020–2025 Dietary Guidelines for Americans, most of us don't get enough of the nutrient. Here's the recommended daily amount of potassium for adults:
- People assigned female at birth: 2,600 mg
- People assigned male at birth: 3,400 mg
You should get most of your potassium from food sources, Jones says. But sometimes that's not possible, which is where over-the-counter or prescription supplements come in.
But what is the best potassium supplement? Here's a breakdown of whether or not you should try a supplement in the first place, plus which form of potassium is best based on your health status and safety considerations.
Food Sources of Potassium
Potassium-rich foods include:
- Greens like Swiss chard and beet greens
- Fish like salmon and tilapia
Should You Take a Potassium Supplement?
If you have a potassium deficiency — a condition called hypokalemia — you may benefit from a supplement, Jones says. Hypokalemia is caused by losing too much potassium, typically through urine, stool or sweat, per the National Organization for Rare Disorders (NORD). It can cause symptoms like:
- Muscle weakness
- Loss of appetite
- Low blood pressure
- Irregular heartbeat
- In severe cases, paralysis or death
People who are seriously ill and hospitalized, especially children, seem to be prone to hypokalemia, according to a September/October 2014 report in the Journal of Intensive Care Medicine. Hyperaldosteronism, which means having too much of the hormone that helps balance potassium and sodium, can also deplete potassium levels, per Kaiser Permanente.
According to the NORD, a number of other factors can also bring about this mineral deficiency, including:
- Taking diuretic drugs
- Overusing laxatives
- Having chronic diarrhea or vomiting
- Not getting enough magnesium
- Kidney disorders
- Intestinal blockages
- Excessive sweating
However, potassium supplements aren't for everybody — just because you have a condition that causes hypokalemia doesn't automatically mean you should take a supplement, as some of these underlying conditions can also respond poorly to too much of the mineral. This potentially life-threatening buildup of potassium is a condition called hyperkalemia.
The takeaway? You may benefit from a potassium supplement if you're low in the mineral, but talk to your doctor before trying one to make sure that it's safe. "They need to be taken under a healthcare professional's supervision, because they can have serious [side] effects if you have kidney issues or are taking diuretics," Jones says.
Types of Potassium Supplements
There are many different forms of potassium, and the supplements can come in powders, granules, liquids, tablets and capsules. Here are the best types of potassium supplements for different health needs.
The best potassium supplement depends on what it's being used for. In general, potassium chloride works well and is the most common supplement for treating hypokalemia, says Maria DeVita, MD, chief of nephrology at Lenox Hill Hospital in New York City.
The potassium chloride supplement is a white powder with a strong salty taste, according to the National Center for Biotechnology Information (NCBI). In fact, in addition to coming in supplement form, it often appears on grocery shelves as a salt substitute, Jones says.
So, how does potassium chloride work? It releases the electrolyte into your system to correct for a deficiency in the mineral, according to an August 2021 StatPearls article.
Buy it: NOW Supplements Potassium Chloride Powder ($5.81, Amazon)
Like potassium chloride, potassium gluconate uses include treating hypokalemia, according to the Office of Dietary Supplements (ODS).
Potassium gluconate is a slightly more complex molecule than potassium chloride: It's a loosely bound salt of potassium and gluconic acid, per the NCBI. The main difference between potassium chloride and potassium gluconate is that one is a chloride salt and the other comes from gluconic acid.
That said, both supplements may effectively treat a mineral deficiency, so default to your doctor's recommendation when deciding between potassium gluconate vs. potassium chloride.
Buy it: NOW Supplements Potassium Gluconate Tablets ($10.84, Amazon)
Potassium aspartate supplements are yet another option to tackle a potassium deficiency, according to the ODS.
This type of potassium supplement is often paired with magnesium, another electrolyte that helps support muscle and nerve function in your body, according to the Mayo Clinic. Talk to your doctor to see if you might benefit from a combination of potassium and magnesium before you try any supplements.
Buy it: Rite Aid Potassium and Magnesium Aspartate Capsules ($9.99, Amazon)
Potassium bicarbonate is another one of the best potassium supplements to treat hypokalemia.
However, it's only accessible with a doctor's prescription, per the Mayo Clinic. So if you suspect you have a potassium deficiency, talk to your doctor about whether this supplement might help you.
Doctors sometimes recommend potassium citrate to people who get kidney stones, says Gerald Hladik, MD, chief of the division of nephrology and hypertension at the University of North Carolina School of Medicine. This supplement may also help prevent kidney stones in people who have gout, according to the Mayo Clinic.
Though they both contain the mineral, the main difference between potassium citrate and potassium gluconate is that one is used to treat kidney stones while the other is used to treat potassium deficiency.
So when it comes to taking potassium gluconate vs. potassium citrate, talk to your doctor to determine what condition you have and which supplement is best.
Buy it: NOW Supplements Potassium Citrate Capsules ($9.85, Amazon)
Another common type of potassium is potassium phosphate, which your doctor may prescribe if you have a phosphate deficiency, Dr. DeVita says. Phosphate is a mineral that plays a role in strong bones and teeth and helps support kidney function, per the U.S. National Library of Medicine.
So, are the different forms of potassium supplements safe? Here are some things to consider before you add them to your regimen.
1. They're Not Recommended If You Have Certain Conditions
Potassium supplements can be dangerous for people with certain underlying health conditions, so talk to your doctor before starting a supplement, according to the National Kidney Foundation. These conditions include:
- Any kind of kidney disease or failure, which can cause potassium to accumulate in dangerous amounts and potentially lead to a heart attack, Dr. Hladik says.
- Addison's disease
- Severe burns or other injuries
- Poorly controlled diabetes
If you do decide to take potassium supplements, your doctor may want to test your blood regularly and perform periodic heart health checks (like an electrocardiogram procedure) to make sure everything is functioning properly.
2. There Can Be Side Effects
Over-the-counter potassium supplements usually contain no more than 99 milligrams of the mineral — well under the daily recommended intake for adults — which makes it difficult to take too much, according to the ODS. But it can happen: Per the Mayo Clinic, some of the less serious side effects of potassium supplements can include:
And consistently having too much potassium in your blood can cause dangerous side effects. Stop taking your supplement and talk to your doctor immediately if you experience any of these symptoms:
- Trouble swallowing
- Pain in your stomach or abdomen
- Black stools
- Irregular heartbeat
- Numbness or tingling
Prescription supplement doses may be higher than 99 milligrams, but you can only take those under the guidance of a doctor who will monitor your potassium levels closely.
3. They Can Interact With Certain Drugs
Potassium supplements can interact with some medications. According to the National Kidney Foundation, these include:
- Certain medications that treat high blood pressure and kidney disease like Lotensin and Cozaar
- Some diuretic medications like spironolactone, amiloride and triamterene
- Certain antibiotics like trimethoprim and pentamidine
- Immunosuppressants for people who have had an organ transplant, like tacrolimus and cyclosporine
- Certain over-the-counter pain medications like aspirin, ibuprofen and naproxen
This is not an exhaustive list, so tell your doctor if you’re taking any other prescriptions or supplements, including over-the-counter pills, vitamins and herbal products.
- U.S. Department of Agriculture and U.S. Department of Health and Human Services: "2020-2025 Dietary Guidelines for Americans"
- National Organization for Rare Disorders: “Hypokalemia”
- Kaiser Permanente: “Potassium Gluconate 595 mg (99 mg) Tablet”
- National Center for Biotechnology Information: “Potassium Chloride”
- Office of Dietary Supplements: “Potassium”
- Mayo Clinic: “Potassium Citrate (Oral Route)”
- U.S. National Library of Medicine: “Phosphorus in Diet”
- Mayo Clinic: "Potassium Supplement (Oral Route, Parenteral Route)"
- Journal of Intensive Care Medicine: "Potassium abnormalities in a pediatric intensive care unit: frequency and severity"
- StatPearls: "Potassium Chloride"
- National Center for Biotechnology Information: “Potassium gluconate"
- Mayo Clinic: "Potassium Bicarbonate And Citric Acid (Oral Route)"
- National Kidney Foundation: "You Kidneys and High Potassium (Hyperkalemia)"
- Mayo Clinic: "I've heard that magnesium supplements have health benefits. Should I take one?"