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Anne Marie Helmenstine, Ph.D.

Why You Don't Need Potassium Iodide for Radiation Poisoning

By March 16, 2011

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Potassium iodide or KI is the chemical most commonly added to salt to make iodized salt. Japan's nuclear risk in the wake the earthquake and tsunami has some people stocking up on potassium iodide tablets and crystals because it can be used to help prevent one certain type of radiation poisoning. Potassium iodide pills have been given out to Japanese evacuation centers and certain other people in proximity to the damaged reactors, but most other people do not need KI and will not benefit from it. The Atomic Energy Commission (AEC) is urging people not to take potassium iodide at this time. Here are some reasons why it won't help you and could hurt you:
  • According to the AEC, if you are in Taiwan or the United States, taking KI outweighs any benefit you might gain from the compound. The level of radiation presently is too low for people to gain a benefit from the drug. Officials advise the Taiwanese that they will have five days warning if the winds change, causing the level of radiation to increase. Potassium iodide is only effective for 24 hours, so taking it now won't protect you against this possibility. If you have KI, do not take it unless and until you are advised to do so by emergency officials.

  • Potassium iodide only protects you from radiation poisoning for radioactive iodine isotopes. It is ineffective against other forms of radiation. Radioactive iodine is only one of the threats posed by a damaged nuclear facility.

  • Potassium iodide confers protection against radiation poisoning from iodine radioisotopes by preventing the thyroid gland from uptaking the radioactive iodine. This is helpful for developing fetuses, babies, children and young adults. The medication doesn't offer a significant benefit to people over the age of 40. For younger people, the only effect of radiation poisoning it protects against is thyroid cancer. Meanwhile, taking KI may make you sick; too much iodine is harmful.
What you can can do to avoid radiation poisoning is to stay inside when fallout is expected, shower and change your clothes when you come in from outdoors and listen for announcements by officials in case the situation changes. If you are in Japan and officials have supplied you with potassium iodide and advised you to take it, be sure to follow additional procedures designed to protect you from fall-out, since the drug will not protect you against all radiation threats.

What Are Radiation Pills?


March 17, 2011 at 10:30 am
(1) spikey says:

And you’re a Ph.D?

‘Potassium iodide only protects you from radiation poisoning for radioactive iodine isotopes. It is ineffective against other forms of radiation. Radioactive iodine is only one of the threats posed by a damaged nuclear facility’

So, because KI ‘only’ protects against one type of cancer risk posed by radiation, you don’t think it’s enough of a reason to take it when required? Where’s the logic in that?!

It’s a bit like saying there’s not much point worrying about preventing cancer or Heart disease, as we’re all going to die of old age at some point!

Also, whilst KI *IS* effective at blocking harmful Irradiated Iodine from Thyroid uptake (by saturation), that is *not* the only reason one would want to use it.

Smaller doses are useful in normal bodily function. People on a poor diet, people suffering from various ailments, insomnia, depression..in fact a whole cornucopia can be treated with KI…so let’s ease off the patronising attitude a little eh?

A better use for this blog space would be to back off from parroting government patronising the adult population, and instead offer advice to people regarding safe dosages and preparatory information for different forms of the chemical.

That way, people would have useful information and can use it safely. Most people want KI to hand as a preparedness measure, rather than buying it and then consuming gallons of the stuff (which of course would be very bad for you indeed)

March 17, 2011 at 1:42 pm
(2) chemistry says:

Iodine is a trace nutrient. The safe dose is probably less than most people get from iodized salt. My point is: it is an unnecessary medication unless you are in Japan, right there next to the release of radioactive iodine. KI will *not* protect you from radiation, only from absorption of iodine radioisotopes, which are not a concern for anyone else at this time. Taking the drug in advance is pointless, since it only works for 24 hours, and also dangerous, since taking too much iodine is as bad for you as having none at all. If you’re over 40 it is both pointless and dangerous, even if you’re in Japan.

March 18, 2011 at 2:38 pm
(3) SpaceCadet says:

I realize that it is difficult to learn how to read amidst all the government conspiracies around you, but try again. Insulting someone by questioning their education credentials makes you, and only you, look like a moron. It doesn’t say “don’t take it because it only protects against one kind,” it is informing people of that fact. Don’t think it protects you against everything labeled as ‘radioactive.’ Talk about easing off the patronizing attitude – why not ease off on being a complete asshole? A better use of this blogspace would be for you to not be on it. Ever. You, who obviously hold no graduate degree, have just made us all a little dumber. By all means, please go eat tons of KI pills with whatever booze it is you’ve been drinking. Don’t forget to bring a foil hat. The gov’t is watching and listening.

March 17, 2011 at 10:39 am
(4) Lanthanum says:

Spikey, please read more carefully. Only people who are exposed to radioactive iodine need KI tablets. People who are not exposed do not need to take KI tablets. They only need to take it when the radioactive iodine comes. I think we can trust the AEC to make the right decision. Overdosing on iodine tablets because a reactor across the ocean is melting down is not a wise course.

Iodized salt is used in the US, so iodine deficiency is rare and KI tablets are not needed.

March 18, 2011 at 12:40 pm
(5) Dr Lantam says:

If iodized salt were as useful as KI tablets then we would prescribe potato chips!
You ALL say taking them before an outbreak of radiation is pointless. However by the time you KNOW of the radiation around you, (remember how useful the govt was at Katrina)
then you will already be exposed and have in IN your thyroid gland.

TAKE it now the cloud is here. LOOK at the weather maps on Youtube.!!!
It is simple. OR… be a sheep and trust in your govt telling you on time.

March 17, 2011 at 11:57 am
(6) Sarah Devon says:

Lugols Iodine Solution is a very good source of Potassium Iodide and is a normal treatment to protect against radiation. It does also have many more benefits, please research.

Please google Lugols Iodine Solution and buy or just research

March 17, 2011 at 12:01 pm
(7) SarahDevon says:

Lugols Iodine Solution is a very good source of Potassium Iodide and is the normal treatment to protect against radiation. It usually comes in liquid form with a dropper and you can get concentrated forms you can dilute yourself.

Lugols Iodine Solution has many uses, please research.

Please google and buy or just research.

March 17, 2011 at 3:06 pm
(8) Conshycrush says:

Spikey… i hope you’re not a chemist. RadioIodine is a byproduct of nuclear fission and only has a half life of 8.02 days. Only a small amount has been said to escape into the air and it would be highly diluted not to mentioned decayed by the time it reached the US shores on the west coast. She’s only referring to the hysteria around people flocking to the pharmacies getting all they can of the stuff. Which is, frankly, insane if you think that fallout would actually reach the US in any significant dosage. If there is a total meltdown of the reactors, Gamma radiation would be released into the air pretty much making those KI pills useless with pretty much everything else unless you live under a lead house!

March 18, 2011 at 2:08 pm
(9) Radioactive Government Sheep says:

Dr Lantam, please be careful around all that radiation. Take as many KI tablets as possible to protect your thyroid. I’m sure the rest of your body will follow your thyroid’s example and not get cancer or radiation sickness — all without the Katrina government’s anti-KI tablet rhetoric!

Did you know your tinfoil hat blocks radioactive alpha particles?

March 18, 2011 at 8:08 pm
(10) Lanthanum says:

You can be a sheep and trust your favorite anti-nuclear environmental group as well as your local KI tablet manufacturer.

March 21, 2011 at 6:53 am
(11) wbranagh says:

Isn’t the iodine generated by the fission process a mixture of I-131 (half life 8 days) and I-129 (half life 15 million years)?

Is the amount of I-129 generated only at the trace level or is the half life so long that there’s effectively nothing you can do to guard against it?

March 21, 2011 at 7:19 am
(12) bigroy says:

Thank you for your considered and thorough advice, Doctor Helmenstine.

We who were children during the 50s an 60s, when atmospheric testing of atomic and nucleur weapons was a weekly, if not daily occurrence have reason to search for places other than government for advice.

I recall when government was telling us, one day that the amount of radiation from the Nevada tests would do us no harm … and the next day that children should not drink milk for the ‘next few weeks;’ that we should rinse the top of every can we open so the can opener doesn’t press radioactive dust into the can.

So we have good reason to double check on government information with independent experts like yourself.

You give me a great deal of reassurance.

Thanks again.


March 21, 2011 at 4:16 pm
(13) ChemTeach says:

Thank you Dr. Helmenstine for your insightful blogs and topics.
I have found your demos and labs to be of great value to my classroom.
My students & I have benefited from your easy-to-understand approach to chemistry.

March 21, 2011 at 4:43 pm
(14) Derril says:

I have to ask after reading this board, what is the average age of the posters? I see a degree of aggression and can only wonder why. It would appear that most maybe teenagers.
What do you think?

March 21, 2011 at 8:31 pm
(15) Relativity says:

Iodine 131 is a relatively short lived isotope and so is only a concern for those near a release of ‘freshly” burned nucelar fuel or a nuclear bomb detonation. This Japanese incident is certainly not any problem for anyone not in the immediate vicinity.

Just because you hear something about radioactive fallout does not mean you need to take KI tablets, it is not required unless you are getting fresh fallout on you. For example if a dirty bomb went off and spread radioactive contamination in your area KI would not help, because the contamination would not have enough (if any) I-131 anymore to worry about.

Don’t forget that when you eat food you are eating a small amount of radioactive material (e.g. potassium-40). The polonium-210 in cigarettes is probably why they cause increased cancer risk. It is importatn to become educated on things nuclear so you make informed decisions. Taking KI tablets at this time does not make sense for this Japanese event if you are farther than 50 miles from the damaged reactors.

June 28, 2011 at 12:22 pm
(16) Bronx says:

Can you explain what you meant by the below? Especially “Damaged Nuclear Facility” Are you implying another one is on the way?

Potassium iodide only protects you from radiation poisoning for radioactive iodine isotopes. It is ineffective against other forms of radiation. Radioactive iodine is only one of the threats posed by a damaged nuclear facility.

July 20, 2012 at 3:57 pm
(17) Scott cooper says:

K iodine tabs & argument for or against, personally I wish I could recall the specific name of the radiation that effects the thyroid but I can’t. I can tell you that taking this as a medication after the “window” of injury does not help as when taken during the exposure. This is also why having it on hand is important. Receiving this after the fact, say a week later, is useless in the treatment of thyroid cancer prevention. Whatever is said for the other reasons to use this I can’t speak of except that it is a great chemical and can be made into many things including a DEA 1 list chemical iodine for drinking water purification with just 2 other chemicals and a filter and water..

June 19, 2013 at 10:10 am
(18) Susan says:

While I appreciate your reassurance about radiation fallout, I would have to say that you are doing your readers a disservice when you say that taking larger doses of iodine is dangerous. I myself have taken 50mg of iodine for quite sometime, and, far from causing toxic effects, it has radically changed my health for the better. And it’s a mistake to call iodine a ‘drug’ — it’s a basic ELEMENT on the periodic table, vital for good health, and in short supply in most of our diets today, causing many health problems that have not yet been recognized by the general medical community — fibrocystic breast disease, PCOS, IBS, poor resistance to infection, heart arrythmias, hypothyroid-like symptoms of all kinds, fibromyalgia, chronic fatigue and others. It would be difficult for me to overstate the importance of all of us adding MORE iodine to our diets, not avoiding it, as is suggested here. Having suffered from many of the problems mentioned above for over 30 years, and having lived the absolute MIRACLE of dramatic heath improvement by taking iodine, I am a staunch advocate for its supplementation — at 54, I’m like a new person and finally have a chance for a normal, healthy life. I hope others reading this will do more research beyond this article and give iodine a try. You would have to be an idiot to actually overdose on iodine, and the potential benefits are numerous and significant. Soon I will reduce my intake to a 12 mg maintenance dose that I will take for the rest of my life — I wouldn’t be without it!

September 7, 2013 at 2:54 pm
(19) Enki says:

Iodine….Helps make people less fat….Makes people Feel all around better and Helps with issues regarding Fluoride Like insomnia and Depression. Commonly Known as the Most important Nutrient To the Occult World and taking it increases Spiritual abilitys (according to the people that Created this country and Law systems you all Conform too.)

Of course they would input into Text books and Curriculum for Newly inspiring Doctors to Learn to Not recommend to others as it helps people to much….no profit in a cure….

Also the Realm of Spiritual Masters is for the Elitists only

This is in no way even close to Conspiracy this is all Easily known information…..The occult World Considers Iodine as one of most important elements to a human being…….Not for the Peons to Use like they do….. Again… this is how your Leaders think.

September 7, 2013 at 2:58 pm
(20) Enki says:

@ susan That is wonderful.

Sadly the Modern Medical system is Trained and Taught to not Cure or Help people and only Peddle Pills the FDA approve……we all know the FDA is Garbage when it comes to Healthy choices.

Some good comes from medicine today but that is nothing compared to the Dark Side of the System.

December 30, 2013 at 7:56 pm
(21) JJ says:

so long as its 1200 std units per day iodine isnt gonna be toxic an if anything its gonna help ur cells purge some of it other chemicals that its using in the place of iodine

Stop hating on Iodine. but like anything dont be taking 20 caps of it a day and think you’ll be fine putting urself in the microwave

February 13, 2014 at 7:45 am
(22) potassium iodide says:

Nice Information. Thanks for sharing lots of information. Its very useful to me

May 3, 2014 at 4:21 pm
(23) trapper says:

i have been taking a gram of iodide a day for years. my labs are all dead center of the norm. i feel great. what harm are you talking about?

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