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
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
When to take
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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