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Stack essential · Deficiency fix

Potassium

Primary electrolyte lost during GLP-1 vomiting/diarrhea, most underrated supplement for this class.

What it is

Major intracellular electrolyte. Drives nerve impulses and muscle contraction (including the heart). Severe deficiency is medically dangerous; subclinical drops cause muscle weakness, fatigue, palpitations.

Why peptide users take it

GLP-1 GI side effects + reduced food intake = potassium loss. Most users associate 'peptide fatigue' with the drug itself when it's often correctable electrolyte loss. Banana + 99 mg potassium gluconate covers most needs without supplement risk.

Pairs with these peptides

Tirzepatide
GI losses + reduced fruit/vegetable intake
Retatrutide
Higher-dose protocols, larger losses
Semaglutide
Chronic users with sustained calorie deficit

How it actually works

Potassium is the main electrolyte inside your cells, while sodium dominates outside. The gradient between them is what drives every nerve impulse and muscle contraction in the body, including each heartbeat. Low potassium = sluggish nerves, weak muscles, irregular heart rhythm. The body fights hard to keep blood potassium in range, but tissue stores can run low long before blood tests flag it.

Dose

Members only

When to take

Members only

Signs you actually need this

  • Muscle weakness, especially in legs climbing stairs
  • Heart palpitations or skipped beats (intermittent)
  • Constipation that doesn't resolve with fiber
  • Tingling in hands or feet that's positional (worse after sitting still)
  • Unexplained fatigue with normal blood sugar

Signs it's working

  • Fewer palpitations within a week
  • Stair-climb leg fatigue resolves
  • Better tolerance for cardio
  • GI motility improves alongside fiber intake

Common mistakes

  • Megadosing oral potassium, high single doses cause GI distress and arrhythmia in susceptible people
  • Taking it with kidney disease without medical clearance, kidneys regulate potassium and disease changes everything
  • Ignoring food sources, banana, potato, leafy greens are massive sources you're already missing on a GLP-1
  • Mixing with high-sodium electrolyte drinks if you're hypertensive, pick low-sodium variants

Where to buy

Editorial picks. Brand selection follows the quality criteria (USP/NSF or third-party COA where possible). Affiliate links , see the disclosure at the bottom of /supplements.

Caveats

  • Don't megadose oral potassium, high single doses can cause GI distress and arrhythmia in susceptible people.
  • Kidney disease changes everything; check with a doctor first.

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Educational reference only. Not medical advice. Talk to a doctor before starting any supplement, especially if you take prescription medications or have an underlying condition.
~900 mg
One baked potato — nine times the standard US potassium pill

What it is

The mineral that runs your heartbeat, blood pressure and every muscle contraction — and the one this catalog deliberately steers you toward FOOD for. Concentrated potassium pills are genuinely dangerous in the wrong kidneys, which is why US supplements typically contain a token ~99 mg.

How it works

Potassium is the counterweight to sodium: more dietary potassium relaxes blood vessels and helps kidneys excrete sodium, which is why high-potassium diets track with lower blood pressure. Your kidneys keep blood potassium in a tight band — great when they work, the whole hazard when they do not.

Which form to buy

Food (potatoes, beans, yogurt, bananas, avocado)Almost everyone

A potato has ~900 mg; a banana ~420 mg. Food packages potassium with water and fiber, absorbed gradually — the safe delivery system.

The answer for nearly every reader.

Potassium chloride "salt substitutes"Clinician-guided sodium reduction

Lite Salt and similar deliver REAL potassium quantities (hundreds of mg per shake) — effective, and exactly why they belong in a medical conversation if you take blood-pressure drugs.

Powerful tool, not a casual one.

99 mg pillsVery little

The near-universal US supplement dose — about a quarter of one banana. An industry convention rooted in old warnings for potassium DRUG products, not a legal cap on supplements (NIH is explicit about this).

Mostly theater; food beats it effortlessly.

Electrolyte powdersSweat replacement

Usually modest potassium alongside sodium — reasonable in genuine sweat-loss contexts.

See the electrolytes entry for that whole story.

What it actually does, graded

Dietary potassium and blood pressure (a recognised diet-level association)Strong

Consistent across trials and cohorts, biggest in people eating high-sodium diets — the basis for guideline advice to eat potassium-rich foods.

Lower stroke risk (dietary)Moderate

Cohort evidence links higher potassium intake with fewer strokes; causality is probable but unproven by RCT.

Fewer kidney stonesLimited

PRESCRIPTION potassium citrate reduces recurrence in selected stone formers (it supplies citrate and alkalinizes urine). That is a condition-specific therapy — it does not establish that dietary potassium generally prevents stones.

Cramp preventionNone shown

The banana-for-cramps folklore has never held up in trials.

Pros and cons

Pros
  • Most people genuinely eat too little (typical US intake ~2,500 mg vs the ~3,400/2,600 mg adequate-intake marks)
  • The food route is cheap, safe and actually works on blood pressure
Cons
  • Concentrated supplemental potassium is the one mineral that can stop a heart when kidneys or drugs impair excretion
  • Pills are either token-dosed (99 mg) or medical-grade — no useful middle
  • GI irritation and ulceration from solid potassium salts is documented

What to expect

  • Shifting the diet potassium-rich: blood pressure drifts down a few points over weeks, most visibly if your sodium runs high.
  • From 99 mg pills: nothing measurable — the dose is symbolic.

Interactions

AvoidACE inhibitors, ARBs, potassium-sparing diuretics, trimethoprim, NSAIDs (examples — the full list is longer: some beta-blockers, heparin, calcineurin inhibitors, digoxin, finerenone…)These impair potassium excretion — adding supplements or salt substitutes on top is the textbook route to dangerous hyperkalemia. Run YOUR whole med list past a pharmacist.
AvoidKidney diseaseImpaired excretion turns normal intakes hazardous — potassium targets there are strictly medical.
MonitorLoop/thiazide diureticsThese DRAIN potassium — your prescriber may deliberately manage it; do not freelance either direction.

Is it for you?

Probably worth it if
  • Blood pressure creeping up and a diet light on produce — the food-first fix
  • You want the highest-yield dietary change, not another bottle
Probably skip it if
  • You expect pills to move the needle — the customary 99 mg dose cannot

Who should avoid it

  • Anyone on potassium-raising medication (the interaction list above is examples, not exhaustive) or with kidney disease — for supplements AND salt substitutes, without explicit clinician approval

Research on this supplement

Papers about this supplement, not proof of the claims above. A title says what was studied, which is sometimes a negative result or a different question entirely.

Evidence base

S
307,373 research papers
Large human evidence base: several phase 3 or 4 trial reports, plus multiple meta-analyses or systematic reviews.

Where next

The full supplement shelfEvery staple, tiered by evidence — not by margin.→What people stack these aroundThe compound index, evidence-graded.→Ask Coach about PotassiumAnswers with the research it stands on.→
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