Story at-a-glance -

• Potassium iodide can be used to block the damaging effects of radioactive iodine. It was one of the solutions used to counteract the effects of radiation from the Chernobyl nuclear power plant disaster in 1986, and in the 2011 Fukushima disaster in Japan
• The thyroid absorbs the stable iodine in the supplement. The excessive amount of stable iodine in the supplement maxes the thyroid gland’s capacity to hold more iodine and, as a result, it will not be able to absorb any form of iodine, whether radioactive or stable, for the next 24 hours

Have you ever been curious as to why table salt is sometimes labeled “iodized?” This is because of potassium iodide, a white crystalline, granular or powdered solid with a strong, bitter and salty taste often added to table salt.1,2

Potassium iodide is also available in supplement form, and can be purchased over-the-counter and on health websites. It has gained popularity because of its ability to protect against the effects of radiation. Keep reading to learn more about potassium iodide’s potential health benefits and what the research has to say about its efficiency.

What is potassium iodide?

Potassium iodide (KI) is a salt of stable and nonradioactive iodine. It appears as transparent or white crystals and is composed of 76% iodine and 23% potassium.3 According to the Centers for Disease Control and Prevention, it helps inhibit radioactive iodine from being absorbed by the thyroid gland — this is the body part that’s highly sensitive to potassium iodide.4

Once a person takes potassium iodide, the thyroid absorbs the stable iodine in the supplement or solution. The excessive amount of stable iodine in the supplement maxes the thyroid gland’s capacity to hold more iodine and, as a result, it will not be able to absorb any form of iodine, whether radioactive or stable, for the next 24 hours.

Take note, however, that potassium iodide doesn’t promise full protection against radioactive iodine. Factors such as time after contamination, absorption and how much radioactive iodine the person has been exposed to can all play a part in how much protection you can get from this supplement.5 Potassium iodide may be administered intravenously to a fluid-restricted patient by a medical professional.6 Otherwise it is orally ingested, and comes in these forms:7

• Oral solution or syrup
• Uncoated tablet
• Enteric-coated delayed release tablet (Note that the delayed release tablet generally isn’t recommended because it can cause serious side effects)

If you take potassium chloride as a supplement, it’s important to remember to always take it with a glass of water and with a meal, or immediately following a meal.8

Potassium iodide’s health benefits

Numerous health benefits have been attributed to potassium iodide, such as:

• Helping protect against the effects of radiation — As mentioned, potassium iodide can be used to block the damaging effects of radioactive iodine. It was one of the solutions used to counteract the effects of the Chernobyl nuclear power plant disaster in 1986 (a liquid solution was used by Poland),9 and in the 2011 Fukushima disaster in Japan.

According to one study, “Potassium Iodide prophylaxis can be administered in order to prevent an increase in the incidence of thyroid cancers in the population of an area affected by a nuclear disaster.”10

• Helping ease respiratory issues — It can be used against infectious respiratory tract diseases as well as pulmonary diseases like emphysema and cystic fibrosis. When taken as a syrup, potassium iodide “acts as an ‘irritating’ expectorant whose mechanism of action will occur by direct irritation of the glands of the respiratory mucosa.”11

• Helping treat dermatological problems — Potassium iodide is an old remedy for various types of skin-related conditions, like basidiobolomycosis,12 sporotrichosis, nodular vasculitis and Sweet’s syndrome, to name a few.13

• Helping correct thyroid issues — One animal study found that goitrogenic rats who were given potassium iodide had improved levels of thyroid hormones.14 However, prolonged intake of this compound can also result in hypothyroidism,15,16 so caution is greatly advised.

Studies on potassium iodide confirm its other uses

Over the years, studies were conducted regarding the effectiveness of potassium iodide for certain conditions, such as:

• Rhinofacial conidiobolomycosis (RFC) — According to a 2016 International Journal of Dermatology study, a combination of potassium iodide and itraconazole can be an effective treatment modality for this disease, which causes facial deformity. The study notes that this combination “has a relatively faster onset of action, low relapse and minimal adverse effects,” making it ideal for primary treatment for RFC patients.17
• Palmoplantar pustulosis (PPP) and pustulotic arthro-osteitis (PAO) — Published in the International Journal of Dermatology in 2017, a study showed that using a potassium iodide formula combined with tetracycline can be utilized to address these conditions.18
• Reduction of lead accumulation — A 2017 International Journal of Occupation Medicine and Environmental Health study revealed that a formula of potassium iodide and chlorophyll, when used as food additives, had the same effects as meso-2,3-dimercaptosuccinic acid (DMSA) in inhibiting lead accumulation among male rats.19
• Graves’ disease — In a study published in the American Journal of Surgery in 2017, potassium iodide given before an operation helped Graves’ disease patients in reducing blood loss during a thyroidectomy. Traditionally, potassium iodide was utilized to prepare patients of the disease before a thyroidectomy.20

Before you consider taking potassium supplements, however, you need to be aware that there are studies that show that potassium iodide may also cause negative effects, especially when taken in incorrect dosages. For example, a 2013 Thyroid Research article showed that potassium iodide, when used in the highest concentrations, increased lipid peroxidation in a concentration-dependent manner.21

This is one reason why taking the right potassium iodide dosage is crucial to avoiding its negative side effects. In fact, the World Health Organization has provided a table of recommended iodine dosage for nuclear or radiological emergencies, depending on age.22

Always consult your physician for the correct dosage, and do not self-medicate. Caution is also advised for pregnant and breastfeeding women,23 as well as people with health problems who are taking medications — more information below.

Side effects of potassium iodide

The Mayo Clinic notes that diarrhea, nausea or vomiting and stomach pain are some side effects that may occur if you take potassium iodide, although they may not require a doctor’s visit, and will go away once your body acclimates to the supplement. However, there are side effects, that may need a physician’s consult immediately, such as:24

• Hives
• Joint pain
• Swelling of the arms, face, legs, lips, tongue and/or throat
• Swelling of lymph glands

Additionally, sometimes long-term use of potassium iodide supplement can trigger side effects such as:

• Burning of the mouth or throat
• Increased watering of the mouth
• Metallic taste in the mouth
• Numbness, tingling, pain or weakness in the hands or feet
• Weakness or heaviness of the legs
• Sores on the skin

• Soreness of teeth and gums
• Symptoms of head cold
• Unusual tiredness
• Irregular heartbeat
• Severe headache
• Confusion

Potassium iodide’s contraindications

If you’re taking medications for certain health conditions you should not use this supplement without precise instructions and careful watch by your doctor. Avoid taking potassium iodide supplements alongside the following medicines because of possible interactions:25

• Acenocoumarol
• Anisindione
• Dicumarol

• Phenindione
• Phenprocoumon
• Warfarin

You have any of the following conditions you should use potassium iodide supplements with caution because of potential reactions:26,27,28

• You are on a low-potassium diet
• You have multinodular goiter
• You have Graves’ disease
• You have autoimmune thyroiditis

• You have hyperkalemia (high blood levels of potassium)
• You have Myotonia congenita

On the other hand, if you have any of the following conditions, you should avoid taking potassium iodide:29,30

• Iodine sensitivity
• People with dermatitis herpetiformis and hypocomplementemic vasculitis — these extremely rare conditions are linked to an increased risk of iodine hypersensitivity
• Nodular thyroid with heart disease
• Tuberculosis — potassium iodide can worsen this condition
• Kidney disease — potassium iodide can increase the amount of potassium in the blood
• An overactive thyroid — Unless you are taking potassium iodide for this medical problem, prolonged use can harm your thyroid gland

Avoid alcohol or tobacco when taking potassium iodide supplements because this can lead to adverse reactions.31 Lastly, avoid using table salt or food as a substitute for potassium iodide and dietary supplements that contain iodine. These can be harmful and nonefficacious.32

Frequently Asked Questions (FAQs) about potassium iodide

Q: Is potassium iodide an electrolyte?

A: Yes, potassium iodide is an electrolyte.33

Q: Is potassium iodide ionic or covalent?

A: Potassium iodide is considered an ionic bond.34

Q: Is potassium iodide soluble in water?

A: Yes. According to the National Institutes of Health’s National Center for Biotechnology Information, potassium iodide is an odorless white solid that sinks and mixes with water.35

Q: Where can you buy potassium iodide?

A: Potassium iodide supplements can be bought over-the-counter or through websites.36

Q: How much potassium iodide should you take daily?

A: It’s best to check with your doctor to know how much potassium iodide you should be taking.