Who gets free potassium iodide (KI) pills in Canada?

Short answer. Potassium iodide (KI) pills are delivered free to every home and business within 10 km of Ontario's nuclear power plants ³⁴ and within 20 km of Point Lepreau, New Brunswick ⁵. People within 50 km in Ontario ⁴ or within the 57 km zone in New Brunswick ⁵ can get them free on request. KI tablets are sold without prescription ⁸⁹¹⁰. Take KI only when public health officials tell you to ¹³.

Who receives KI pills automatically?

Two zones get pills without asking:

• Ontario, within 10 km of a nuclear power plant: pills are mailed to homes and businesses. The Canadian Nuclear Safety Commission (CNSC) requires this pre-distribution ³⁴.
• New Brunswick, within 20 km of Point Lepreau: pills were distributed to every residence and business in summer 2021 ⁵.

Who can order them for free?

When should you take KI?

Only when instructed by public health officials ¹³. KI works best when taken immediately before exposure or as soon as possible after it ³. An official alert will say if KI is part of the instruction; near Pickering, alerts can tell residents to shelter in place, take KI pills or evacuate ².

Our guide potassium iodide: when to take it and who needs it explains what KI does and does not protect against, and the doses by age.

How long do KI pills last?

The CNSC states: "KI pills are effective for up to 12 years if they are stored in a dry location between 15 and 30 °C" ³. Keep them with your emergency kit, in that temperature range, and note the date you received them.

Can you buy KI at a pharmacy in Canada?

Yes, KI is a non-prescription product in Canada, but no official source says which pharmacies stock it. Health Canada licenses potassium iodide thyroid-blocking tablets as natural health products, each with a Natural Product Number (NPN) ⁸⁹. Examples:

The licensed use is "thyroid blocking agent for use in nuclear emergencies which involve the release of radioiodine" ⁹. Under the Natural Health Products Regulations, a product whose sale requires a prescription cannot be a natural health product ¹⁰. Health Canada notes that "not marketed" in its database only means the company has not declared sales ⁸.

In Ontario, Ontario Power Generation's KI supplier is New Roots Herbal, and Radblock is the product sent through preparetobesafe.ca; every pill contains 65 mg of KI ¹¹. Health Canada's Drug Product Database, which covers prescription and non-prescription drugs, lists no currently marketed KI tablet: THYROSAFE 65 mg was cancelled in 2008 and THYROBLOCK 130 mg in 2003 ⁶⁷.

If you live inside the zones above, the free supply is the official route ³⁴⁵.

Frequently asked questions

I live within 10 km of an Ontario nuclear plant and have no pills. What should I do?

Homes and businesses in that zone should receive pills by mail ³⁴. Anyone within 50 km can order them free through preparetobesafe.ca ⁴.

Should I take KI as soon as I hear about a nuclear incident?

No. Take it only when public health officials tell you to ¹³. Follow the instruction in the alert, which may be to shelter in place rather than take pills ².

Do KI pills expire?

They remain effective for up to 12 years when stored dry between 15 and 30 °C, according to the CNSC ³.

Do I need a prescription for KI in Canada?

No. KI thyroid-blocking tablets are licensed as natural health products, a category that excludes prescription products ⁸⁹¹⁰.

Who do I call in New Brunswick?

The New Brunswick Emergency Measures Organization supplies KI on request in the 57 km zone: 1-800-561-4034 ⁵. More numbers are on our Canada emergency contacts page.

Sources

1. Public Safety Canada (Canada.ca) — Radiological and nuclear emergencies – Get prepared — https://www.canada.ca/en/services/policing/emergencies/preparedness/get-prepared/hazards-emergencies/radiological/how-prepare.html (accessed 2026-10-20)
2. City of Pickering — Nuclear Emergencies — https://www.pickering.ca/en/living/NuclearEmergencies.aspx (accessed 2026-10-20)
3. Canadian Nuclear Safety Commission (CNSC) — Potassium iodide pills – Quick facts — https://cnsc-ccsn.gc.ca/eng/resources/emergency-management-and-safety/potassium-iodide-pills-quick-facts (accessed 2026-10-20)
4. Ontario Ministry of Health (via Ontario Healthline) — Radiation Health Response Plan (Ontario Ministry of Health service listing, updated 2025-05-08) — https://www.southwesthealthline.ca/displayservice.aspx?id=173971 (accessed 2026-10-20)
5. Government of New Brunswick (NB Emergency Measures Organization) — Nuclear Emergency Preparedness Program — https://www.gnb.ca/en/topic/laws-safety/emergency-preparedness-alerts/nuclear-emergency-preparedness.html (accessed 2026-10-20)
6. Health Canada — Drug Product Database: THYROSAFE (DIN 02247850) — https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=72157 (accessed 2026-10-21)
7. Health Canada — Drug Product Database: THYROBLOCK TAB 130MG (DIN 00518077) — https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=4436 (accessed 2026-10-21)
8. Health Canada — Licensed Natural Health Products Database: Radblock TM (NPN 02248172) — https://health-products.canada.ca/lnhpd-bdpsnh/info?licence=02248172&lang=en (accessed 2026-10-21)
9. Health Canada — Licensed Natural Health Products Database: Potassium Iodide, New Roots Herbal Inc. (NPN 80086446, 65 mg tablet) — https://health-products.canada.ca/lnhpd-bdpsnh/info?licence=80086446&lang=en (accessed 2026-10-21)
10. Justice Laws Website (Government of Canada) — Natural Health Products Regulations (SOR/2003-196), section 2 — https://laws-lois.justice.gc.ca/eng/regulations/SOR-2003-196/page-1.html (accessed 2026-10-21)
11. Durham Region Health Department — Potassium Iodide (KI) pills in Durham (FAX about... for health care professionals, 9 March 2026) — https://web.archive.org/web/2026id_/https://www.durham.ca/en/health-and-wellness/resources/Documents/ResourcesforHealthCareProviders/FaxAbout/2026/Potassium-Iodide-KI-Pills-March-09-2026.pdf (accessed 2026-10-21)