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Allergic to Magnesium?

3 August 2012 - Posted by Ashley under ,

I recently had a phone call with someone who told me that they were allergic to sea water.

At first, I admit, I was a bit skeptical – but then I realized, why should I be…our bodies being the strange, yet wonderfully complex, biological systems that they are. So, I sat back to listen to the background on this completely new topic for me, and it really had me wondering. If someone can be allergic to sea water – which contains high amounts of magnesium chloride, on top of the more well known sodium chloride – how would that affect them in terms of transdermal magnesium use?

As with most of these conversations, I was instantly crawling all over the internet seeking answers and details on how this could relate to magnesium chloride use, and finding some very interesting information to share.

So here is the question that I know is on your mind now – Can you be allergic to topical magnesium chloride?

The answer? Yes. Yes you can. But then again, you can be allergic to just about anything these days – even water!

To go further into the “hows” and “whys” of this, I’ll start by saying that a true magnesium allergy is extremely rare. After all, our bodies need magnesium to function. Not want, or like, or prefer – need. They require it like a car engine requires oil – no ifs, ands or buts about it. However, as our population becomes exposed to more and more toxins in our environment, less diversity in our food system, more antibiotics and gut-flora-disrupting pharmaceuticals, etc.,  we’re seeing a significant rise in corresponding health issues such as Auto-Immune Diseases and Multiple Chemical Sensitivity.

From what I’ve found, hypersensitivity to magnesium is relatively new in the grand scheme of things and wasn’t actually documented in medical journals until 1990. At this time, two pregnant women were treated with  a prepared solution of intravenous magnesium sulfate (MgSO4) to try and stave off premature labor. Both of these women developed an urticarial rash (hives) within a short period of time, which disappeared once the MgSO4 was discontinued. Although, to be clear, it was never deciphered whether it was indeed the MgSO4 that was the culprit as opposed to the dextrose, sulphur, leaching of chemicals from the plastic bag, or other contaminant in the IV preparation. Additionally, despite the fact that this occurrence was documented 22 years ago, clinical documentation of magnesium hypersensitivity remains difficult to find.

Why? Because a magnesium allergy is completely contradictory to everything that magnesium stands for – in fact, it’s biologically absurd.  In a healthy human body, magnesium is a natural anti-inflammatory; it’s key in histamine metabolism and naturally reduces histamine production. Are you seeing the irony yet?

With a magnesium allergy, your body reacts to magnesium exposure as though it is battling a pathogen, resulting in the release of immunoglobulin E (igE) antibodies, histamine and other chemicals. This inflammatory response can manifest as a rash* (moderate – severe) or urticaria, difficulty breathing, rhinitis, dizziness, swelling of the limbs or throat, etc.. Although an extreme magnesium allergy may require you to carry epinephrine and wear a medical alert bracelet, the average allergic reaction should subside with the administration of a mild antihistamine.

*Please do not mistake the common itching sensation or slight redness from transdermal magnesium use for an allergic reaction. There is a vast difference between hypersensitivity to magnesium that causes hives and the normal itching sting of magnesium salts on your skin.


Also, keep in mind that magnesium is necessary in the body for proper detoxification, therefore, may cause detoxification symptoms with its use. Detoxification symptoms include headache, fatigue, brain fog, body ache, and other similar ailments. 

So, now that we know that this phenomenon exists, allow me to touch on some additional information…

Why haven’t I heard about this before now?

As I mentioned above, magnesium hypersensitivity is not just rare, but also appears to be a rather new and poorly documented affliction. Most of the information that you’ll find on this subject will be of the anecdotal variety, surfacing mainly in forum discussions, blog posts, and social media commentary. Alongside those, you may run into the occasional vague mentions in clinical studies & medical journals. In fact, this information is so very elusive, I’d almost call it Bigfoot if I didn’t know it to actually exist.

Is it possible to circumvent an allergy to magnesium?

To a certain extent, it may be possible to still supplement with magnesium despite a sensitivity. Many of the allergic responses to magnesium seem to be a result of simply getting too much magnesium at once. In essence, it’s your body’s way of saying “Whoa, slow down!”. I would liken it to feeding someone suffering from starvation – despite the fact that the body needs food to survive, pushing too much and/or the wrong types of food onto a sensitive digestive system can be extremely harmful and even fatal. The same consideration should be made when dealing with a sensitivity to magnesium.

Using smaller, more mild dosages, trying different types of compounds, and building up your internal magnesium stores slowly, are all things to consider if you are dealing with a mild allergic reaction to magnesium.

In terms of our Ancient Minerals line specifically, try diluting the magnesium further than what is suggested in the instructions – for the magnesium oil, you could try a dilution of 25/75 rather than the 50/50 that we suggest in the application guide. If that is still too strong, you can try diluting it further or simply stick to an application such our bath flakes.

If you are in the small group of people that are extremely allergic, however, use of magnesium even in small amounts would not be recommended (obviously).

If I’m allergic to one magnesium compound, does that mean that I’m allergic to all of them?

No, it’s very possible that you could simply be allergic to that specific compound. There are over 20 different forms of magnesium available as supplements – depending on your reaction, you could try switching to a different form. However, please consult with your physician should you decide to explore that route.

If I’m allergic to magnesium supplements, does that mean that I’m allergic to foods containing it as well?

No. The oddest aspect of hypersensitivity to magnesium is that, unlike normal allergies, it usually* does not include magnesium-rich foods. For this reason, those who have found themselves highly allergic to magnesium supplements are usually sent to a dietician to help them plan out meals geared specifically towards meeting their magnesium needs.

*I say “usually” because I have not found evidence that supports a complete negation on this, but neither have I found any to support a response to the positive.


If you have any questions or comments on this topic, feel free to call, email, or simply comment.

Please Note: If you suspect that you may have an allergy to magnesium, it is recommended that you see your doctor for allergy testing.

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  • Amber

    Hello,
    I recently purchased Ancient Minerals Magnesium Oil and excitedly slathered by body with it, only to find the next day that the areas covered had come up in a rash – not Hives, but rather very fine red dots. I very rarely react to anything so this is rather curious to me. I use only natural, organic skin care products. Could it be a cleansing reaction? I have taken Magnesium supplements of several varieties and never had a rash or clear reaction before, with the exception of (excuse me), loose bowel movements if I overdo it. I would appreciate any guidance/support. Thanks in advance.

  • Donna

    years ago I took magnesium as a supplement, but I would get a headache each time I tried. I would wait sometimes a year apart to see if my body had changed I could take it. Still got the headache, so I quit all together. I had a colonoscopy later and got so sick, like the flu. Almost fainted. Last fall I found that I had a ulcer and gerd. Was given 40mg of omeprazole. After taking it for about 2 weeks my upper legs hurt me so bad I could hardly walk. When I called and told the Dr. he told me to take pepicid, and that did the same to my legs, only a little worse pain. I was scheduled to have a colonoscopy and was given the stuff to drink and got so sick and threw it all up. Called the dr and was given something different, but with the same drink. I was 10 times sicker this time. After I threw up I was ok. So no colonoscopy. My gerd and ulcer were bothering me so I went and talked to the Pharmacist, and while talking to her, she mentioned that all the medicines that help gerd have magnesium in them. So, I asked her about the stuff you drink for a colonoscopy and she said that it has magnesium in it. I put 2 and 2 together and was sure I have some kind of allergy to magnesium. I have not had a dr. confirm that, but I don’t know what else to think. Please, if anyone else has had any thing like this let me know, and if you have any answers.

  • Joy

    i have a severe cardiocircolatory reaction to magnesium chloride: my blood pressure goes way down, and i collapse. ( i allredy have a very low blood pressure). i am not allergic to other forms of magnesium. my question: wich is the most effective magnesium compound afther magnesium chloride? thanks !

  • Sharon Bullard

    Hi Ashley
    I have just read your article. I know it is a few years old but I found it so helpful.
    I have had this rash between my breast and under my right breast for over one year. I have seen my doctor so many times regarding it. She said it was from sweat. I work in a gym.
    I have also been spending a fortune seeing a kinesiologist who has eliminated so many things from my diet believing it was all the things i was eating causing the rash. For example removing caffeine,soy, dairy from my diet.Nothing has helped. I myself have made the connection to magnesium. I have been taking it in supplement form for the same time as I have had the rash. My doctor put me on a course of steroids out of pure frustration by me.
    This stopped the rash for one week, I then started taking my magnesium again due to leg cramps and the rash has returned. It is so itchy and I find it is worse at night. Do you have any suggestions as to how to get rid of the rash, I have stopped the magnesium again (now I know the cause) but the rash has not yet disappeared?
    Any suggestion that you can give me has to help. I am at whits end with this.
    Thank you in advance if you can help

  • Tiff

    Hi, I have just read twenty of these stories. I think it is clear that the magnesium oil is super strong and should be diluted down considerably. There should be clear “Rash warnings” on the bottle! Imagine a mother slathering it on a childs’ body or even worse their face! I have taken oral tablets and been fine, but the other day my husband and I were informed by the pharmacist to buy the spray. Three days later I have a pimply, pussy rash on my face, I did dilute it considerably. I am allergic to sunscreen and moisturisers, I have good skin but not at the moment. It is like I have acne. I hope my face gets better soon. Really pissed off as on the label it says great to reguvinate skin. As they say “unless you can eat it safely” dont put anything on your face. All marketing, all bullshit.

  • KERRIE

    My doctor told me my magnesium was so so I began taking a supplement. I developed a severe rash on my left leg that itched so bad it created lesions. I have used neosporin, gold bond intensive healing….after I stopped taking magnesium the rash finally started to subside, but has left terrible scars. I have used mederma to try to make the scars leave. I also got some lesions on my arms. How do I get the scars to fade???

  • Liz

    I got the Hives reaction as well. I currently have a case of poison oak, so that might be why I reacted. I am also allergic to Nickle, I break out in small hives at the contact point. Is anyone else? It might be a link.

  • Fairpoint is NOT Fair

    I had magnesium post pardum. I was SO SO SO sick. Years later I developed a hive condition (Angioedema). Magnesium supplements and any medications that have Magnesium Sterate in them bother me immensely.

    Magnesium is often suggested to ease hives.

  • Kristine

    Your rash is likely a yeast infection and is exacerbated by sweating. Wash the area twice a day, dry thoroughly (even using a fan if needed) and apply the cream in a tube from the dollar store used for athlete’s foot (you can also use women’s vaginal yeast cream but it is more expensive and doesn’t work any better.) You will be amazed. Also, the area you are describing needs air. My doc told me to lay on the bed after my shower and hold up my breasts and just let the air dry you really well.

  • Kristine

    Utter cream – the little green, square tin can in the pharmacy.

  • Emily

    This product really needs a clear warning on it about possible side effects. Judging by the amount of comments on this post there are ALOT of people who react to it. Yay to hives and itchy skin… NOT. I wouldn’t even know if it actually helps because I’m so irritated by my skin.

  • ley

    Hello, My boyfriend just gave me a vitamin c drink. A few minutes later my face was burning hot and stinging. It spread to my arms I felt my whole body on fire. I looked in the mirror and my face was red and blotchy. It was on my arms hands elbows knees, backs of my legs. It was like the picture you have. I asked my boyfriend what was in the drink and he said he added magnesium to it. I googled allergy to magnesium and found your page. Thank you. I now think it was the brand. As I have taken magnesium supplements before. But it was horrid, Its beginning to calm down now, after I made him make me a cup of nettle tea for penance!..

  • sheila

    I have read these comments with interest. I have been taking magnesium oxide 500 mg per day for several months for constipation and about 2 weeks ago I started itching all over my torso. Can’t really see a rash but so itchy especially at night that it keeps me awake. I really cannot pinpoint any other cause of the itching other than the magnesium.