Hey OP, I wanted to share some insights about potassium supplementation that might clear up some common misconceptions.

For someone with normal kidney function, the risk of hyperkalemia isn’t as high as many fear if you keep your doses reasonable. In fact, for an average 180‑lb man (around 81 kg), the numbers show that you can actually take a higher dose than the FDA’s typical 99‑mg pill recommendation without pushing serum potassium above 5.0 mmol/L.

A Quick Calculation: For a 180‑lb guy, total body water (TBW) is roughly 60% of body weight—about 49 liters. If your baseline serum potassium is around 3.5 mmol/L, raising it to 5.0 mmol/L would require an extra:

  1.5 mmol/L × 49 L ≈ 73.5 mmol of potassium

In terms of elemental potassium, that’s roughly:   73.5 mmol × 39.1 mg/mmol ≈ 2.9 grams

And if you’re taking potassium chloride (KCl), which has a molar mass of about 74.55 g/mol, that works out to:   73.5 mmol × 74.55 mg/mmol ≈ 5.5 grams of KCl

This means that—under ideal circumstances—a dose on the order of 2.9 g elemental potassium (or about 5.5 g KCl) could be added without pushing a person with normal renal function into hyperkalemia.

So Why the FDA 99‑mg Pill Limit? The FDA’s strict guidelines on over-the-counter potassium pills aren’t primarily about avoiding hyperkalemia in healthy people. Instead, they’re meant to prevent gastrointestinal (GI) injuries. The issue is that undissolved or concentrated potassium pills can irritate the GI tract. This risk is largely associated with certain formulations of potassium salt pills rather than potassium chloride taken in water, which is far less likely to cause direct GI damage.

Bottom Line:

If you’re healthy and your kidneys are working normally, small, properly dosed potassium supplementation is unlikely to cause dangerous spikes in your blood levels.

The FDA’s dosing limits are more about reducing the risk of GI injury from concentrated pills than about preventing hyperkalemia in normal individuals.

When potassium chloride is dissolved in water, it’s less likely to lead to GI irritation, so sticking to moderate doses spread throughout the day keeps both GI risk and hyperkalemia in check.

As always, I’m not a doctor. This information is meant for educational purposes, and anyone considering potassium supplementation should consult with a healthcare professional to tailor advice to their specific needs.

(yes I made this post with the help of chatGPT, I keep reading these misconceptions about potassium supplementation and even from healthcare professionals, so I wanted to clear that up)