What Are Electrolytes? Benefits, Imbalances & When to Use Supplements
You finish a hard workout and your legs start cramping. You're three days into a low-carb diet and the fatigue hits like a wall. Or you're recovering from a stomach bug and can't shake the brain fog. In each case, there's a good chance electrolytes are part of the picture.
Electrolytes are among the most important, and most misunderstood, minerals in the body. This guide explains what they are, what they do, what happens when levels drop, who benefits most from supplementation, and how to choose the right approach for your needs.
What Are Electrolytes?
Electrolytes are minerals that carry an electric charge when dissolved in water. In the body, they facilitate the movement of electrical signals through nerves and muscles, regulate fluid levels, and support hundreds of biochemical processes.
The seven key electrolytes in the human body are:
- Sodium (Na+)
- Potassium (K+)
- Magnesium (Mg2+)
- Calcium (Ca2+)
- Chloride (Cl-)
- Bicarbonate (HCO3-)
- Phosphate (PO43-)
These minerals are present in blood, urine, tissues and other bodily fluids. They're obtained primarily through food and drink, and lost through sweat, urine and digestion.
Source: National Institutes of Health, Electrolyte Imbalance
Why Electrolytes Matter: Key Functions
Electrolytes aren't just about hydration. They're involved in nearly every major system in the body.
Hydration and Fluid Balance
Sodium and chloride regulate the amount of water inside and outside your cells. When electrolyte levels drop, the body struggles to maintain proper fluid distribution, which can lead to dehydration even when you're drinking water. Research shows that even mild dehydration can impair mood, memory and brain performance, particularly in women (Armstrong et al., Journal of Nutrition, 2012).
Nerve Function
Your nerves communicate through electrical impulses called action potentials. Sodium and potassium ions are essential for generating these signals. Without adequate levels, nerve transmission slows, which can affect everything from reaction time to coordination.
Muscle Function and Recovery
Calcium, magnesium and potassium work together to control muscle contraction and relaxation. Deficiencies in any of these can lead to cramps, fatigue, spasms and slower recovery after exercise.
Source: Institute of Medicine (2004), Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate.
pH Balance
The body maintains blood pH within a very tight range of roughly 7.35 to 7.45. Bicarbonate acts as a buffer, neutralising excess acids and keeping this balance intact. Disruptions to pH can impair enzyme function and cellular processes throughout the body.
Blood Pressure Regulation
Electrolytes influence how much water the body retains and the tension in blood vessel walls, both of which directly affect blood pressure. A high-sodium, low-potassium diet is linked to increased risk of hypertension.
Source: World Health Organization, Guideline: Sodium intake for adults and children (2012)
Cognitive Function and Immune System Support
Magnesium plays a role in neurotransmitter regulation and nervous system function, which can influence mood, focus and mental clarity. Electrolyte balance also supports immune cell function, making adequate levels important for overall resilience, particularly during illness or periods of stress.
Signs of Electrolyte Imbalance
Electrolyte levels can fluctuate for a number of reasons, and the symptoms are often mistaken for general tiredness or stress.
Common causes include:
- Excessive sweating during exercise or in hot climates
- Vomiting or diarrhoea
- Chronic kidney disease
- Use of diuretics or certain medications
- Poor diet or malnutrition
- Alcohol consumption
- Prolonged fasting or very low-carb diets
Symptoms to watch for:
- Fatigue and low energy
- Muscle cramps or weakness
- Headache
- Nausea
- Brain fog or difficulty concentrating
- Irregular heartbeat
- Dizziness
In more serious cases, severe electrolyte imbalances can lead to heart arrhythmias, seizures or loss of consciousness. If you experience persistent or severe symptoms, see your GP.
Source: Mayo Clinic, Electrolyte Imbalance Symptoms and Causes
Who Benefits Most From Electrolyte Supplements?
Electrolyte supplements aren't just for marathon runners. Several groups may benefit from targeted replenishment beyond what food alone provides.
Athletes and Active Individuals
During intense or prolonged physical activity, especially in hot or humid conditions, significant amounts of sodium, potassium and magnesium are lost through sweat. Replacing these can help maintain performance, reduce cramping and support faster recovery.
A 2016 study in the Journal of the International Society of Sports Nutrition found that athletes who replenished electrolytes recovered faster and performed better in subsequent training sessions.
If you train regularly, browse our sports supplements range or read our guide on amino acids and muscle recovery.
Older Adults
As we age, the sense of thirst diminishes, making dehydration more likely. Medications commonly prescribed to older adults (particularly diuretics and blood pressure drugs) can also interfere with electrolyte balance. Regular, moderate supplementation may help maintain energy, cognitive function and muscle strength.
People on Low-Carb or Keto Diets
Low-carb diets cause the body to excrete more water and sodium through urine. This can lead to the cluster of symptoms known as "keto flu," including dizziness, fatigue, headaches and cramps. Replenishing sodium, potassium and magnesium often alleviates these symptoms quickly.
Source: Volek, J., & Phinney, S. (2011). The Art and Science of Low Carbohydrate Living.
People With Digestive Issues
Conditions like IBS, Crohn's disease, or episodes of vomiting and diarrhoea can rapidly deplete electrolytes. In these situations, oral rehydration with electrolytes is essential for recovery and preventing further complications.
People in Hot Climates or Physical Jobs
If your work or environment involves sustained heat exposure, your sweat losses may exceed what a standard diet replaces. Construction workers, kitchen staff, warehouse employees and anyone working outdoors in summer may benefit from regular electrolyte replenishment.
→ View our electrolyte supplements
Electrolyte-Rich Foods
A balanced diet provides a solid foundation of electrolytes. The best natural sources include:
- Sodium: table salt, olives, soy sauce
- Potassium: bananas, potatoes, avocados, spinach, oranges
- Magnesium: nuts, seeds, whole grains, leafy greens
- Calcium: dairy products, fortified plant milks, leafy greens
- Chloride: table salt, seaweed, celery, tomatoes
Some particularly electrolyte-dense options worth adding to your routine include coconut water (rich in potassium), bone broth (sodium, calcium and magnesium) and avocados (potassium and magnesium).
However, in situations involving heavy sweating, illness, fasting or restrictive diets, food alone may not replace what's been lost quickly enough. That's where supplementation can fill the gap.
How to Choose an Electrolyte Supplement
Not all electrolyte products are equal. Here's what to look for:
- A balanced mineral profile: avoid products that are mostly sodium. Look for a mix that includes potassium, magnesium and calcium
- Low sugar or natural sweeteners: many sports drinks contain as much sugar as fizzy drinks, which can offset the benefits
- Bioavailable forms: ingredients like magnesium citrate are better absorbed than cheaper oxide forms
- Convenient format: powders, tablets and capsules each have advantages. Powders dissolve quickly for rapid replenishment; capsules are easier for daily routine use
Our electrolyte powder provides a balanced blend of key minerals in a lemon-flavoured format designed for easy mixing.
→ Browse all electrolyte supplements
A Note on Safety
For most healthy people, electrolyte supplements are safe when taken as directed. However, overuse can lead to hypernatremia (excess sodium), hyperkalemia (excess potassium) or kidney stress in individuals with existing kidney conditions.
If you take diuretics, blood pressure medication, or have a chronic health condition, consult your GP or pharmacist before starting electrolyte supplementation.
Source: Cleveland Clinic, Electrolyte Disorders
Frequently Asked Questions
What are the main electrolytes in the body?
The seven key electrolytes are sodium, potassium, magnesium, calcium, chloride, bicarbonate and phosphate. Each plays a distinct role in hydration, nerve signalling, muscle function and pH balance.
What are the symptoms of low electrolytes?
Common symptoms include fatigue, muscle cramps, headaches, nausea, brain fog, dizziness and irregular heartbeat. Severe imbalances can cause more serious issues including heart arrhythmias and seizures.
Do I need electrolyte supplements if I eat a healthy diet?
A balanced diet provides a good foundation. However, supplements can be helpful during intense exercise, illness, hot weather, fasting, or when following a low-carb or keto diet, as these situations can deplete electrolytes faster than food alone replaces them.
Are electrolyte supplements safe?
For most healthy people, electrolyte supplements are safe when taken as directed. However, excessive intake can cause problems, and people with kidney disease or those taking diuretics or blood pressure medication should consult their GP before supplementing.
What is the best way to replenish electrolytes after exercise?
An electrolyte powder or tablet dissolved in water is one of the fastest ways to replenish minerals lost through sweat. Look for a product with a balanced mix of sodium, potassium and magnesium rather than sodium alone. Pairing this with electrolyte-rich foods like bananas or coconut water can also help.
Can you have too many electrolytes?
Yes. Excess sodium can raise blood pressure and cause fluid retention. Excess potassium can cause heart palpitations and muscle weakness. Stick to recommended dosages and consult a healthcare professional if you have any underlying conditions.
Summary
Electrolytes are essential for hydration, nerve signalling, muscle function, pH balance and cognitive performance. Most people get adequate levels through a balanced diet, but athletes, older adults, keto dieters, people recovering from illness and anyone exposed to sustained heat may benefit from targeted supplementation.
The key is choosing a quality product with a balanced mineral profile and using it in the situations where your body needs the extra support.
