Salt Substitutes and ACE Inhibitors or ARBs: Hidden Potassium Risks

Many people switch to salt substitutes thinking they’re making a healthy choice-especially if they’re trying to lower their blood pressure. But for those taking ACE inhibitors or ARBs, that seemingly harmless swap could be dangerous. These substitutes often replace sodium chloride with potassium chloride, and when combined with certain blood pressure medications, they can push potassium levels in your blood to life-threatening levels. This isn’t a rare side effect. It’s a quiet, widespread risk that many patients don’t even know about.

What Are Salt Substitutes, Really?

Salt substitutes are marketed as healthier alternatives to regular table salt. Products like LoSalt, NoSalt, and Heart Salt contain anywhere from 25% to 100% potassium chloride instead of sodium chloride. A typical "lite" salt blend is half sodium, half potassium. Pure substitutes like LoSalt are about 66% potassium chloride. That means one teaspoon of these products can deliver 400-600 mg of potassium, compared to almost none in regular salt.

On the surface, this sounds good. Potassium helps relax blood vessels and lower blood pressure. The American Heart Association recommends reducing sodium to under 2,300 mg a day, and many people consume over 3,400 mg daily-mostly from processed foods. So swapping salt for a potassium-based version seems like a win. But here’s the catch: your kidneys need to work well to get rid of extra potassium. If they’re not functioning properly, potassium builds up.

Why ACE Inhibitors and ARBs Are a Problem

ACE inhibitors (like lisinopril, enalapril) and ARBs (like losartan, valsartan) are among the most common medications for high blood pressure, heart failure, and kidney protection in diabetics. They work by blocking the renin-angiotensin-aldosterone system (RAAS), which helps regulate blood pressure and fluid balance. One of the side effects? Reduced aldosterone production-by 30% to 50%. Aldosterone tells your kidneys to excrete potassium. Less aldosterone means less potassium leaves your body.

Now add potassium-rich salt substitutes on top of that. Your body is taking in more potassium while simultaneously losing the ability to flush it out. This double hit can cause hyperkalemia-dangerously high potassium levels in the blood. Levels above 5.0 mmol/L are considered elevated. Above 6.5 mmol/L, you risk cardiac arrest. A 2004 case report in the Journal of the Royal Society of Medicine documented a 72-year-old patient who suffered cardiac arrest after using LoSalt while on nabumetone and with mild kidney impairment. His potassium level hit 7.8 mmol/L.

Who’s at Highest Risk?

The biggest risk group isn’t just people on these medications-it’s people on these medications and with kidney problems. About 15% of U.S. adults have chronic kidney disease (CKD), according to CDC 2022 data. That’s roughly 37 million people. Of those, about 14.5% have an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73m², meaning their kidneys can’t efficiently remove potassium.

Diabetics are especially vulnerable. Up to 20% of diabetics with kidney disease have hyporeninemic hypoaldosteronism-a condition where the body makes even less aldosterone. The American Diabetes Association specifically warns that this group faces a "disproportionately high" risk of hyperkalemia when using potassium salt substitutes.

Even if you don’t know you have kidney disease, you might still be at risk. Many people with early-stage CKD feel fine. No swelling. No fatigue. Just quietly declining kidney function. That’s why screening matters.

The Numbers Don’t Lie

Research shows how serious this is. A 2019 meta-analysis of over 1.2 million people found that hyperkalemia occurred at a rate of 0.8 events per 100 person-years in the general population using salt substitutes. But for those with CKD and on ACE inhibitors or ARBs? That jumped to 8.7 events per 100 person-years-more than ten times higher.

And it’s not just theory. Reddit threads, Drugs.com reviews, and Amazon feedback are full of stories: "Woke up in the ER with potassium at 6.3 after using Heart Salt for 3 weeks on lisinopril." "Severe muscle weakness and irregular heartbeat after switching to potassium salt while on losartan." These aren’t outliers. They’re predictable outcomes.

Meanwhile, a 2025 JAMA Network study showed potassium-enriched salt substitutes reduced stroke recurrence by 14% in 21,000 people with normal kidney function. But that study excluded people with eGFR under 60. The benefits? Real. The risks? Real too. It’s not a one-size-fits-all solution.

What About Other Ways to Cut Salt?

You don’t need potassium chloride to lower sodium. Herbs, spices, citrus, vinegar, garlic, and onion powder can reduce sodium intake by 40-50% without any potassium risk. Products like Mrs. Dash are sodium-free and potassium-free. They don’t have that metallic aftertaste that 28% of users complain about in Amazon reviews. They’re cheaper, too-most cost under $3 for a 12-ounce container, compared to $5-$6 for potassium-based substitutes.

And here’s the thing: most of the sodium in your diet comes from packaged and restaurant foods-not the salt shaker. Cutting back on processed snacks, canned soups, deli meats, and frozen meals does more than any salt substitute ever could. A 2022 Mayo Clinic study found that 63% of hyperkalemia cases in people on ACE inhibitors or ARBs came from dietary potassium sources like salt substitutes, not supplements.

What Should You Do?

If you’re on an ACE inhibitor or ARB, here’s what to do right now:

1. Check your salt substitute. Look at the ingredient label. If it says "potassium chloride," stop using it.
2. Ask your doctor for a blood test. Get your serum potassium level checked. Normal is 3.5-5.0 mmol/L. Anything above 5.0 needs attention.
3. Know your kidney function. Ask for your eGFR. If it’s below 60, avoid potassium substitutes entirely.
4. Switch to herbs and spices. Use garlic, paprika, cumin, lemon zest, black pepper, and dried herbs to flavor food. They work.
5. Don’t assume "low sodium" means safe. Many low-sodium products replace sodium with potassium. Read labels like a detective.

The National Kidney Foundation and American Society of Hypertension now recommend that doctors ask every patient on ACE inhibitors or ARBs about salt substitute use at every visit. Yet a 2023 JAMA Internal Medicine study found that 78% of patients on these drugs didn’t even know dietary potassium could be dangerous.

The Bigger Picture

The global salt substitute market is growing fast-projected to hit $2.3 billion by 2030. But regulation lags. In the U.S., the FDA doesn’t require warning labels on potassium salt substitutes for people on ACE inhibitors or ARBs. Canada did-starting January 2024. Only 3 out of 12 major brands in the U.S. voluntarily warn about this risk.

The FDA proposed new labeling rules in May 2024, but they won’t be final until at least mid-2026. Until then, the burden is on you and your doctor.

Final Thought: It’s Not About Fear-It’s About Awareness

Reducing sodium is important. Managing blood pressure saves lives. But if you’re on an ACE inhibitor or ARB, potassium salt substitutes aren’t a shortcut-they’re a trap. The good news? You don’t need them. You can still eat flavorful, heart-healthy food without touching a single gram of potassium chloride.

Talk to your doctor. Get tested. Switch to herbs. Your heart-and your kidneys-will thank you.