Avoiding iodine has been stock advice for acne patients for several decades now. Iodine is said to cause acne. But is it so? Does iodine really cause acne? That’s what I’m trying to answer with this post.
Given that pretty much everybody knows that iodine aggravates acne I was surprised to find very little evidence to back it up. Apparently it was established in the 1960s that iodine (and related chemicals) in drugs can trigger acneiform eruptions in some cases. Acneiform means acne-like and in addition to common acne also includes things like psoriasis and dermatitis breakouts. But as far as we patients are concerned acne is acne so there’s no need to split hairs with different medical terms.
I could also find a few cases reports about iodized table salt and kelp (high in iodine) triggering acne breakouts. The breakouts resolved after excess dietary iodine was removed from the diet.
I also found a Concise International Chemical Assessment Document about iodine. It’s published by The World Health Organization and seems to be fairly comprehensive review of the topic. Here’s what it said about iodine and the skin.
Oral exposure to markedly excess iodide can produce skin lesions, referred to as ioderma, which are thought be a form of cell-mediated hypersensitivity…
Characteristic symptoms include acneiform pustules, which can coalesce to form vegetative (proliferating) nodular lesions on the face, extremities, trunk, and mucous membranes. The lesions regress and heal when the excess iodide intake is discontinued. The clinical literature includes cases of ioderma that occurred subsequent to oral doses of iodide at 300–1000 mg/day
Note that the RDA for iodine is 150 micrograms (µg) for adults. The above report refers to 300 – 1000 milligrams (mg), which is about 2000 to 7000 times higher than the RDA. The FDA also reviewed the toxicity reports of iodine and concluded iodine intake of 1 mg per day is probably safe for the majority of population, but can cause symptoms in some people.
So we can conclude that high intake of iodine may cause acne in some sensitive individuals. But that this intake probably requires either high intake of iodized salt, kelp or other high-iodine food, or medication or supplement with high levels of iodine.
What about dietary iodine and acne?
But can iodine from normal diet cause acne? One study in 1961 tried to answer this. They took a group of people from three different regions of North Carolina. The regions selected has very different iodine intakes, given that one was a coastal region, one was in the mountains and the third in between. They measured the intake of iodine from food, water and salt and correlated it with rates and severity of acne.
They found that people who ate more iodine had the same rates of acne than those who ate less iodine. So iodine from dietary sources had no effect in acne.
This is just one study from 50 years ago. How much we can trust it I can’t say.
Conclusion
Does iodine cause acne? We don’t have enough evidence to say for sure. But it seems safe to conclude that abnormally high intake can trigger acne breakouts in some individuals. But this probably requires that you eat a lot of iodine-rich foods (such as kelp or iodized salt) or get iodine from supplements or medications.
While intakes from normal diet are probably not a problem, it’s a good idea to try low iodine diet. You might get lucky and find a simple solution to a complicated problem.
Hi Seppo – I found you from the Jaminet’s PHD site, so you may have read this in their book already. They recommend supplementing iodine, but increasing the dose slowly. The iodine, which is a beneficial micronutrient, displaces bromine (undesirable) from tissues, and the free bromine temporarily causes acne as one of the side effects. However, the bromine is excreted through sweat and urination, so it is a short-lived phenomenon. I have been supplementing iodine as they recommend, and sure enough, I have had small break-outs each time I increase the dose, but they subside quickly. I used to have serious acne problems but I have mostly cleared things up through dietary and skin-care changes, but I am still hyper-aware of every little pimple. I think your site is really interesting and I applaud you for putting all this in one place!
Interesting point about iodine and bromine. Didn’t think about it from that angle. Thanks for sharing!
Hi Laura,
I start to use iodine slowly. It’s “Illomodine” which is consider the most powerful one.
I didn’t know until recently how it’s related but now I am so sure about my adult acne.
I have been very clear skin more than last 10years. But all of sudden I feel this skin rash or acne one by one. It’s not the same acne when I had in my teen. And it’s more around my ear (where the lymph nods are located). I am sooooo under comfortable and almost wanting to stop this supplement even though I am iodine deficiency. I used other acne product thinking it’s pimple, but it’s not working because it’s not a sebum problem and I don’t have oily skin.
Does your skin got better? What can I do? 🙁
I just had a CT scan that included iodine via IV and after that I broke out w a zillion pimples all over my face, and even a couple small ones on my chest (rare). Even for that many pimples on my face was rare. I hadn’t really changed my diet or anything else in the last few days so all I can associate it with is the iodine/CT scan.
I break out when I eat too much seaweed and I love seaweed as a snack. I thought it’s because of the seasoning (maybe it has gluten) but it might be because of iodine. However, maybe I should avoid them if I am at risk of Hashimoto.
Thanks for sharing your experiences Tree and sed.
If I eat anything with carrageenan, seaweed, or anything related to these items I break out pretty bad. Same reaction if I use any products topically with these ingredients. It could be the iodine but not sure.
I just began supplementing kelp to displace my high bromide intake. My facial skin has been breaking out like crazy, but I figure this is due to the bromines being “pushed out” of my body.
My nails have also grown very quickly due to the kelp,
I definitely think Iodine causes acne. I normally have clear skin. I started taking Iodine supplements to help boost a sluggish thyroid. I immediately broke out in acne, extremely bad, all over my face. It was so bad that I couldn’t leave the house. As soon as I stopped taking the iodine, the acne went away. It took a few days, but it cleared up. It had to be the iodine. I wasn’t taking anything else.
I cut iodine from my diet years ago because of the acne/iodine problem . I buy iodine free table salt , multi vitamins ect. . Because they all caused acne problems for me . But now I think I am having iodine deficiency problems . afternoon fatigue , acid indigestion . Luckily I just read a study that claims taking niacin counters the acne effects of iodine . I will try it and let you know .
Taking zinc will clear up the acne caused by iodine supplementation. I take this ‘Stress B-complex’ supplement that contains zinc with a meal about an hour after I take iodine. My skin has never looked better.
After reading this article, I’m curious how “fermented cod liver oil” are known to be helpful with inflammatory acne when it has high iodine?
2 things. First, just because “it’s known” that fermented cod liver oil helps acne doesn’t mean it is. There are a lot of misconceptions about acne and getting over it online. Second, you probably need to take a lot of iodine for it to trigger acne.
I recently received radioactive iodine to treat thyroid cancer and barely a week later and for the eight weeks following my skin has been a rash of acne. I do have sensitive skin, but my skin has been pretty clear for the past few years. Initially I thought an ingredient had been changed in my regularly used soaps/cleaners, but after some research and switching to others I found this was not the case. The only thing different was the treatment with radioactive iodine after a couple of weeks on a low iodine diet. The iodine will stay in my system for a few months, so time will be the test. Seems to hold some truth at this point as the breakouts were sudden and abnormal to my normal skin activity. It appears there are others posting on the internet that can relate and likely even more that have not made the association with the two. Thank you for posting about this possible link.
In my teens I figured out that any amount of iodized salt would give me the worst kind of pimples, as if I’d had caffeine and dairy, but sea salt was fine. The effect was so bad that I avoided iodine all these years until a week ago. I’ve been tired and depressed for two years and it occurred to me I might be iodine deficient. I took 150 mcg drops once a day and on the third day I had acne. I’m in my 30s–last week I was slathering thick moisturizer on my dry skin, as usual; now it’s benzoyl peroxide! Thanks to the comments for the bromine info–I might try to stick it out… P.S. I’ve been taking zinc and active B vits for months and they didn’t protect me from the iodine, personally.
I’m 59 yr old male and have been ever so slowly breaking out on my cheeks mostly and a little bit on forehead. Couldn’t figure out why until now. I started snacking on seaweed about a year ago and that’s when my skin began to flare up. I haven’t had any breakouts since my teens either. I just remembered learning to stay away from too much iodine as a teenager and kind of forgot about it I guess. I’ve always had sensitive skin by the way. I think this is the problem most likely and will stop eating seaweed snacks.
Living in a tropical climate I have suffered at times more so early teens to 18ys ‘now 61 yrs old whenever I take electrolyte suppliment staminade I break out with the odd painfull acne pimple ‘found also ‘pineapple to cause problems and chocolates ‘contrary to what my platoon sergeant told me once son when you can grow a beard properly you won’t have anymore problems with your skin’funny enough. ‘
About 5 years ago I started getting crazy acne but I couldn’t pinpoint the cause… fish sauce (as an ingredient), seaweed, shellfish, canned tuna, even swimming in the ocean–I never knew when it would trigger or to what degree, just that the above things seemed to be the cause… and it could be bad–to the extent that I didn’t want to leave the house what with people grimacing asking “what happened to your face,” it’s kind of annoying. Did I mention I’m in my 40s and never had an acne problem in my life. Just last week I made the iodine connection and am pretty convinced the mystery of my “seafood” facial rashes has been solved. Like someone mentioned above, my lymph areas behind my ears and framing my face around my forehead would be the worst. Like my body was trying to push this toxic stuff out through the skin. Which is why I 100% agree with your comment about the “acne” actually being “acneiform eruptions.” Glad to finally have the answer! Thanks for the post.