Quick answer

Electrolytes are charged minerals, mainly sodium, potassium, magnesium and chloride, that keep fluid balance, nerves and muscles working. Food supplies most of them: Americans already average about 3,400 mg of sodium a day. A drink matters mainly in long, hot or very sweaty exercise, where guidance is about 300 to 600 mg of sodium an hour.^1,2,3

Key facts

Sweat holds roughly 230 to 1,600 mg of sodium per liter, so two people doing the same workout can lose very different amounts.⁴
Sodium is the electrolyte sweat removes in the largest amounts; very little potassium leaves that way.^4,5
FDA calls a serving high in sodium when it has 20% or more of the Daily Value, which works out to 460 mg.²
Water you drink starts reaching the blood within about 5 minutes.⁶
In healthy people the kidneys hold blood sodium and potassium steady, so a normal diet rarely moves them.⁷

What electrolytes are

Electrolytes are minerals that carry an electric charge when dissolved in body fluids such as blood. The main ones are sodium, potassium, chloride, magnesium, calcium, phosphate and bicarbonate.¹

Electrolytes help balance the amount of water in the body and its acid level, move nutrients into cells and wastes out of them, and keep muscles, nerves and the heartbeat working normally.¹

This page covers the four that drink mixes are built around: sodium, potassium, magnesium and chloride. Calcium, phosphate and bicarbonate are electrolytes too, but this page does not cover them.¹

Potassium is the main mineral inside cells, about 30 times more concentrated there than outside, while sodium mainly governs the fluid outside cells, including blood plasma.⁵

That split across the cell wall is what lets a nerve send a signal and a muscle fiber shorten. Sodium also pulls water along with it, which is why fluid taken with sodium after a hard, sweaty session stays in the body longer than plain water does.^5,8

Blood levels of sodium and potassium are usually not changed by what you eat, because the kidneys and hormones hold them steady.⁷

What the evidence shows

Two claims pass our review. Each shows its grade and the amount behind it, so you can see whether a given drink or meal comes close.

Sodium replaces what is lost in sweat and helps the body hold on to fluid after long or heavy-sweat exercise*^3,4,8,9

Moderate evidence

Sodium's role in fluid balance is well established. Sports nutrition guidance suggests taking sodium mainly for exercise longer than about 2 hours, for heavy or salty sweaters, or in heat, at about 300 to 600 mg an hour; one scoop is roughly the sodium in a liter of average sweat. A modelling study found sodium replacement unnecessary in realistic scenarios for a soccer match or a marathon, so for shorter sessions it is likely a matter of taste, not need.

Amount studied: About 300 to 600 mg of sodium an hour during exercise lasting more than about 2 hours, in heat or with heavy sweating

Potassium and magnesium contribute to normal muscle and nerve function*^5,10,11,12

Moderate evidence

A long-established role of both minerals, described by NIH and included for each of them in the EU list of permitted nutrient-function statements. What counts is the daily total from food and drink: adults need 2,600 to 3,400 mg of potassium and 310 to 420 mg of magnesium a day, and most supplements supply only a small part of that, often no more than 99 mg of potassium per serving. It describes a normal function, not a gain from taking more than you need.

Amount studied: Recommended daily intake from all sources: potassium 2,600 to 3,400 mg, magnesium 310 to 420 mg

Neither claim means more is better. Many Americans do eat less potassium than recommended, but a drink mix is a poor fix for that: most potassium supplements carry 99 mg or less per serving, while one baked potato has about 610 mg.^5,10

A 2022 review of sodium in endurance sport found no documented evidence linking sodium intake to exercise cramps, so this page makes no cramp claim.³

When a drink makes sense

NIH notes that athletes in endurance activities lasting more than an hour, or in very hot conditions or at high altitude, might need to replace lost fluids and electrolytes.¹³

A modelling study found that replacing sodium was unnecessary in every realistic scenario for a soccer match or an elite marathon, and mattered mainly in very long events with heavy drinking and salty sweat.⁹

In practice that splits people into two groups. An hour of lifting in a cool gym costs little that food and water will not replace. Several hours of running, riding or outdoor work in the heat, especially if you know you sweat a lot or sweat salty, is where replacing sodium along the way is reasonable.^3,13

Typical sports drinks hold about 230 to 690 mg of sodium per liter. One review advises against drinks above about 1,000 mg per liter because they become unpleasant to drink.³

How much of each you need

Daily amounts for adults, from food, drink and supplements together^2,5,14,15
Mineral	Daily amount	Worth knowing
Sodium	Less than 2,300 mg (the Daily Value)	Americans average about 3,400 mg
Potassium	3,400 mg for men, 2,600 mg for women	No upper limit for people with healthy kidneys
Magnesium	400 to 420 mg for men, 310 to 320 mg for women	No more than 350 mg from supplements
Chloride	2.3 g to age 50, 2.0 g to age 70, then 1.8 g	Comes mostly from salt

The dosage page goes further, with amounts for pregnancy and the hourly sodium figures used for long events.

Electrolytes in food

Over 70% of the sodium Americans eat comes from packaged and prepared foods, not the salt shaker. Deli meat sandwiches, pizza, burritos and tacos, soups and savory snacks are among the biggest contributors.²

Dried apricots (755 mg of potassium per half cup), cooked lentils (731 mg per cup), acorn squash, prunes, raisins, a baked potato (610 mg), kidney beans, orange juice and a banana (422 mg) are among the richest sources. Milk, yogurt, meat, fish and nuts add more.⁵

Food is also how most people replace what a workout costs. A rehydration review found that the electrolytes needed after exercise can come from food eaten with a drink, which for an ordinary session means a normal meal and water.¹⁶

What's in ours

What’s in ours

Creatine + Electrolytes: Sodium, 1,000 mg per serving, from the label

One scoop of Creatine + Electrolytes has 1,000 mg of sodium, 43% of the Daily Value, more than twice the 20% that FDA counts as high. That is a lot of salt for a day without much sweating, so it suits long or sweaty training days better than rest days.²

Its 200 mg of potassium and 60 mg of magnesium are small next to daily needs of 2,600 to 3,400 mg and 310 to 420 mg.^5,14

Side effects, medicines, and who should ask first

Diets high in sodium are linked to a higher risk of high blood pressure, a major cause of stroke and heart disease, and blood pressure tends to rise with age.²

Too much potassium from supplements or salt substitutes can raise blood potassium (hyperkalemia), especially with kidney disease or medicines that keep potassium in the body. It often causes no symptoms, but severe cases can cause dangerous heart rhythms.^5,17

Drinking well beyond thirst during long exercise can dilute blood sodium, a condition called exercise-associated hyponatremia. Overdrinking is its most common cause, and severe cases are an emergency.^18,19

Sodium: the Daily Value is less than 2,300 mg a day from all sources. Potassium: no upper limit is set for healthy people with normal kidney function, because the kidneys pass the excess, though very large amounts from supplements or salt substitutes can still raise blood potassium. Magnesium: 350 mg a day for adults from supplements and medicines, not counting food.^2,5,14

Ask your pharmacist or doctor first

Losartan and other angiotensin receptor blockers (ARBs) reduce how much potassium leaves in urine. The losartan label says other products that raise blood potassium can lead to high potassium, and tells patients not to use potassium supplements or salt substitutes containing potassium without asking their healthcare provider.^5,17,20

On the medicine's label

Avoid the combination unless your doctor advises it

Spironolactone keeps potassium in the body. Its label says taking it with potassium supplements can lead to severe high potassium, and that patients should be advised to avoid potassium supplements and foods high in potassium, including salt substitutes.^5,21,22

On the medicine's label

Ask your pharmacist or doctor first

Lisinopril and other ACE inhibitors can raise blood potassium. The lisinopril label lists potassium supplements and potassium-containing salt substitutes as risk factors, and tells patients not to use such salt substitutes without asking their physician.^5,23

On the medicine's label

Ask your pharmacist how far apart to take them

Magnesium, found in many electrolyte mixes, can bind tetracycline and quinolone antibiotics in the gut so less of the antibiotic is absorbed. The ciprofloxacin label tells patients to space the antibiotic away from supplements that contain magnesium, and the doxycycline label says antacids containing magnesium impair its absorption.^11,14,24,25

On the medicine's label

Ask your pharmacist or doctor first

Lithium levels depend on salt and fluid balance. The lithium label tells patients not to change the amount of salt in their diet, and says that if heavy sweating occurs, extra salt and fluid should be given only under medical supervision.²⁶

On the medicine's label

Your doctor may want to check on you

Loop and thiazide diuretics (water pills) increase the potassium and magnesium lost in urine, while potassium-sparing diuretics hold on to both. Experts advise monitoring potassium in people taking these medicines.^5,11

Reported in studies

Do not use an electrolyte product if a doctor has told you to limit salt or potassium, unless that doctor has approved it
Ask your doctor first if you have high blood pressure, heart failure, or kidney or liver disease
Ask first if you take a blood pressure medicine, a water pill, lithium, or a medicine that raises potassium
Ask first if you are pregnant or breastfeeding, or are an older adult who already eats a salty diet²⁷
If vomiting or diarrhea is the reason you want electrolytes, especially for a child or an older adult, ask a doctor what to drink²⁸

Questions people ask

Do I need electrolytes every day?

Not as a supplement, for most people. Food supplies sodium, chloride and some potassium and magnesium, and Americans already average about 3,400 mg of sodium a day. A drink earns its place when sweat losses are large.^2,13

Are electrolyte drinks better than water?

At rest, usually not by much. In a study of 72 men, a typical sports drink was kept in the body no better than water, though an oral rehydration solution and milk were. Sodium makes the clearer difference after heavy sweating.^8,29

Are electrolytes good for your skin?

A PubMed search found no human trials of electrolyte drinks for skin, so this page makes no skin claim. The two graded claims above are the only ones that passed our review.

What do electrolytes do for your body when you are sick?

Vomiting and diarrhea can drain fluid and electrolytes fast. MedlinePlus says mild cases may need only water, sports drinks can help when minerals are lost, and oral rehydration solutions exist for children. Get medical help for confusion, fainting, no urination or a racing heart, and ask a doctor before giving any mix to a child or an older adult.²⁸

Can you have too many electrolytes?

Yes. Years of high sodium intake raise the risk of high blood pressure, potassium from supplements can build up when the kidneys or a medicine hold on to it, and more than 350 mg a day of magnesium from supplements can cause diarrhea. Drinking far more than you sweat can also dilute blood sodium.^2,5,14,18

See what we make

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See the Full Measure line Creatine + Electrolytes

Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.