Salmiak, the salty liquorice candy popular across Scandinavia and the Netherlands, is fine in small amounts but can cause real health problems if you eat a lot of it regularly. The two ingredients that matter are ammonium chloride (the salt that gives salmiak its sharp, tangy bite) and glycyrrhizin (a compound naturally found in liquorice root). Both are harmless in modest doses, but in larger quantities they can disrupt your body’s acid balance, lower potassium levels, and raise blood pressure.
What Makes Salmiak Different From Regular Candy
Salmiak gets its distinctive flavor from ammonium chloride, a simple salt with the chemical formula NH₄Cl. Regular liquorice candy contains glycyrrhizin from the liquorice root extract, and salmiak combines that with ammonium chloride for a salty, almost astringent taste. The concentration of ammonium chloride varies by brand, but it’s typically between 2% and 8% of the candy’s weight. Some extra-strong varieties marketed to adults push even higher.
Each of these two compounds affects your body through a different pathway, and eating enough salmiak means you’re getting a double dose of trouble: one ingredient pushes your blood toward being too acidic, while the other disrupts your sodium and potassium balance.
How Ammonium Chloride Affects Your Body
When you eat ammonium chloride, it dissolves in your digestive system and splits into ammonium and chloride. Your liver processes the ammonium by converting it into urea, and that process uses up bicarbonate, one of the main buffers your blood relies on to stay at a stable pH. The result, if you consume enough, is metabolic acidosis: your blood becomes slightly more acidic than it should be.
For a healthy person eating a few pieces of salmiak, your kidneys compensate easily. They ramp up acid excretion and restore balance within hours. The problem arises with heavy, sustained consumption. In one documented case, a woman with pre-existing kidney issues who took 6 grams of ammonium chloride daily for six months developed profound metabolic acidosis serious enough to send her to the emergency room with exhaustion and severe difficulty breathing. Her kidneys simply couldn’t keep up with the acid load.
You’d have to eat quite a lot of salmiak candy to reach 6 grams of pure ammonium chloride in a day, but people who snack on bags of the stuff regularly, especially the extra-strong varieties, can approach concerning levels over time. If your kidneys are already compromised for any reason, the threshold for harm drops significantly.
Glycyrrhizin, Blood Pressure, and Potassium
The liquorice component of salmiak carries its own set of risks, centered on glycyrrhizin. This compound interferes with an enzyme in your kidneys that normally keeps cortisol (a stress hormone) from activating receptors meant for aldosterone, a hormone that regulates salt and water balance. When glycyrrhizin blocks that enzyme, cortisol floods those receptors unchecked. Cortisol is present at concentrations 100 to 1,000 times higher than aldosterone, so the effect is dramatic: your kidneys start retaining far more sodium and flushing out potassium.
The consequences are a rise in blood pressure, a drop in potassium, and sometimes fluid retention. This relationship between liquorice and blood pressure is dose-dependent and linear, meaning more liquorice equals higher blood pressure. Even 50 grams of liquorice daily (containing roughly 75 mg of the active compound glycyrrhetinic acid) consumed for just two weeks can cause a measurable rise in blood pressure. At 400 mg of glycyrrhizic acid per day, most people will experience adverse effects.
Potassium depletion is the more immediately dangerous risk. Potassium is critical for muscle function, including your heart. In one case reported in Mayo Clinic Proceedings, a patient’s potassium dropped to 1.7 mEq/L, well below the normal range of 3.5 to 5.0, causing severe muscle paralysis. The culprit was regular liquorice consumption combined with liquorice-containing tea. That level of potassium depletion can trigger heart rhythm problems.
Who Faces the Highest Risk
People with kidney disease are especially vulnerable because their kidneys can’t efficiently clear the extra acid from ammonium chloride or compensate for the potassium loss driven by glycyrrhizin. Anyone already taking diuretics (water pills) should be cautious, since ammonium chloride can amplify the effects of certain diuretics, and both diuretics and glycyrrhizin independently lower potassium. Stacking all three creates a serious risk of dangerously low potassium.
People with high blood pressure or heart conditions should also be careful, since even moderate amounts of glycyrrhizin can push blood pressure higher. If you’re on medication to control hypertension, regular salmiak consumption could partially undo what your medication is doing.
Salmiak During Pregnancy
Pregnant women have particular reason to limit salmiak. A Finnish study tracking children whose mothers consumed liquorice during pregnancy found striking differences. Children whose mothers consumed high amounts of glycyrrhizin (500 mg or more per week) scored an average of 7 points lower on intelligence tests compared to children whose mothers consumed little or none. These children also had 3.3 times the odds of attention deficit/hyperactivity problems, and performed worse on memory tests.
Girls in the high-exposure group also showed signs of accelerated physical development: they were taller, heavier, and further along in puberty than their peers. The researchers concluded that liquorice consumption during pregnancy may be associated with harm to the developing child. Several Nordic health authorities now recommend that pregnant women avoid liquorice and salmiak products entirely.
How Much Is Too Much
There’s no single universal threshold, but some practical guidelines emerge from the evidence. For the glycyrrhizin component, 100 mg per day is enough to cause problems in sensitive individuals, and 400 mg per day causes problems in most people. The amount of glycyrrhizin in salmiak varies widely by product, so a handful of mild salmiak candies is very different from half a bag of strong ones.
As a rough guide, eating a few pieces of salmiak occasionally poses minimal risk to a healthy adult. Problems tend to show up when people eat large quantities daily over weeks or months. The classic patient in case reports is someone who goes through a bag or more per day as a regular habit, not someone who has a few pieces at a party.
If you notice symptoms like muscle weakness, unusual fatigue, heart palpitations, or swelling in your legs and ankles after a period of heavy salmiak consumption, those are signs your potassium may be dropping or your blood pressure may be climbing. Stopping the candy typically allows levels to normalize, though severe cases can take weeks to fully resolve.