MSM Side Effects: What You Need to Know Before You Take It

| Modified on Oct 30, 2023
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MSM Supplement Side Effects

Methylsulfonylmethane (MSM) is a popular health supplement known for its ability to relieve arthritis and pain. However, like any supplement, MSM can cause mild to severe side effects. The amount you take, other medications you take, and your own personal constitution will affect how MSM works for you.

In this article, we will discuss some of the potential side effects of MSM and how to avoid them.

MSM Side Effects

1. Heart Issues

One of the most concerning side effects of MSM is its potential to affect the heart. Some people have reported experiencing heart palpitations, tightness in the chest, and increased blood pressure after taking MSM.

2. Emotional Side Effects

Emotional side effects caused by MSM can be equally as debilitating and frightening, including anxiety and mild to severe depression. Mood swings may also be more pronounced.

A number of Earth Clinic readers have reported a severe case of anxiety one to two days after starting MSM.

3. Skin Issues

MSM can also affect the skin with rashes, dry skin, hives, and itching.

4. Digestive Issues

Digestive side effects can include gas, foul stools, constipation, diarrhea, and urine retention.

Additional Side Effects

Other commonly reported side effects of MSM include:

  • Headaches 
  • Migraines 
  • Insomnia 
  • Muscle Cramps 
  • Increased Thirst 
  • Dehydration 
  • Fatigue 
  • Exhaustion
  • Dizziness
  • Nausea
  • Vomiting
  • Allergic reactions (such as itching, swelling, or difficulty breathing)
  • Flushing
  • Excessive Sweating
  • Kidney Problems (in rare cases)

How to Avoid MSM Side Effects

To avoid these side effects, it is important to start slowly and increase your dosage gradually.

Check labels and use a quality brand recommended by someone you know or a natural health practitioner.

Take MSM early in the day and with food to minimize the risk of side effects.

It is also important to be aware that some individuals may be more susceptible to side effects from MSM, including those with a history of reactions to sulfa drugs, mood disorders, and nutritional deficiencies.

MSM: Is it for Everyone?

MSM may not be suitable for everyone, and certain groups of people may be at higher risk of experiencing side effects. If you have a history of reactions to sulfa drugs, you may also have trouble with MSM. People with mood disorders may also be more likely to experience serious psychological side effects such as anxiety and depression when taking MSM. Additionally, if you have mild to serious nutritional deficiencies, MSM could exacerbate the problem by depleting molybdenum, an essential trace mineral.

If you take prescription or over-the-counter medications regularly, MSM may affect the way your medications work. It is important to consult with a healthcare provider before taking MSM if you have any underlying health conditions or are taking any medications.

In conclusion, while MSM can provide many health benefits, it may not be suitable for everyone. It is important to be aware of the potential risks and consult with a healthcare provider before taking MSM if you have any concerns. If you experience any side effects or have any concerns about taking MSM, it is important to consult a healthcare provider.

Continue reading below for feedback from our readers who have experienced many of the side effects listed below after they started taking MSM.  Have you experienced side effects from MSM? We would love for you to share your experience with us!


8 User Reviews

Posted by Kelly (Seattle) on 06/07/2016

In response to Cat from Nevada's post in the arthritis section regarding anxiety and heart palpitations from MSM

I began after using the MSM gel for my arthritic knees and thumb. I experienced almost immediately within 2 days better movement and no pain in my knee, hip and thumb. On the 4th day I even walked a mile with my grandchildren which I was unable to do since April of 2014. My allergies were gone, and so was brain fog, I felt fantastic and could move around and be normal but? I began experiencing heart palpitations on day 5 and felt quite uneasy. They continued until I became frightened. I wrestled with feeling fabulous or heart problems as I do not like feeling disabled at 56, but have discontinued the product. This morning my walking is worsened, the pain is coming and my allergies are terrible. So extremely sad. I was taking 1/8 teaspoon once a day and had increased to 1/4 2 times a day. Any ideas?

According to the 'inventor' of MSM, Dr. Stanley Jacobs, MSM is a "cholinesterase inhibitor. Cholinsterase is an enzyme that stops excessive passage of nerve impulses from one nerve cell to another."

So if this cholinesterase enzyme is INHIBITED by MSM, then one may develop worsening anxiety, muscle twitching, cramping, and yes, heart palpitations, etc., -- all the symptoms of excess choline or acetylcholine.

I found this out the hard way, experiencing worsening leg cramps, muscle twitching and anxiety.

It may help some who have very low levels of choline, but should be avoided by others.

Replied by Trisha
(Columbus, Indiana)

I believe this is my problem! I've had other issues with high acetylcholine with fish oil supplements. I never put two and two together that MSM could affect choline levels. My joints and muscles have gotten terrible since starting MSM. Did your symptoms go away quickly after stopping MSM?

Replied by Charity
(Faithville, Usa)

I use a lot of msm and vitamin c and it can deplete molybdenum and that makes some problems.

Molybdenum reduces symptoms of candida die off and also helps create enamel on teeth, from what I have read.

Replied by Madeline
(New York)

This is to Kelly. I see this is an old post but in case you see it, I wanted to suggest something. You were having such great effects from MSM, its a shame to have to go back to being disabled in so many ways. The suggestion I want to make is to try taking Magnesium. There is a supplement called "CALM". My husband gets racing heart palpitations occasionally. Especially after or during exertion (he is a Chef so working conditions can be fast paced and hot). When he drinks a dose of "CALM" during those incidents, it stops rather immediately. My best to you.


Yes, magnesium is important. I think I may have leaky gut or my system doesn't absorb what it requires. I have to take 2-3 400mg magnesium, a banana for potassium and use Himalayan salt every day or my calf cramps at night and heart palpitations can be brutal. Calm is good but after taking it for 2 years, my teeth became sensitive to the citric acid. Someone here on EC suggested Black walnut for tooth sensitivity and it works very well.

(Gaborone, Botswana)

Have you tried applying magnesium oil? This absorbs very easily into the body through the skin. It might sting when you first use it, but I find very calming and helps me keep my magnesium intake optimal.

Posted by Om (Hope, Bc, Canada) on 06/03/2013

Re MSM side effects. I purchased MSM in crystal form. When I put 1/8th teasp. to my mouth I had instant pictures in front of my eyes of people in panic and an allover anxiety message. Now I am not suffering of anxieties nor do I do drugs. But since then I have sprinkled it over my pets' food but have not the courage to try it again. I don't think I swallowed it.

I wonder if this supplement works on the lower chakras as I have had experience with herbs and even homeopathics causing effects that, lets say, were not "wholesome" and in effect were psychedelic experiences. I believe these supplements work differently on the individual, as in old and established medicine systems it is imperative to know ones Doshas, otherwise healing can be mere guess work.

I don't like unwelcome mental experiences so I stay away from a product if this happens. Om

Posted by Kathy (Covington, Virginia) on 11/26/2010

I have read all the feedback on msm. Now I am confused. I am having pain in my knees and legs. Have for sometime. I mix 2 capsules of msm in lotion and apply as much as needed. This seems to help, but not for long. I would like to start taking msm by mouth, but now if it causes anxiety i can't do that. I already have chronic anxiety and am taking zoloft, have been for ten years. The msm i use is pure. What can i do?

Replied by B

According to my own (bad) Experiences, I do explicitly NOT recommend taking MSM together with Zoloft (Sertraline). MSM can strongly affect the Effects of SSRI-Antidepressants.

Posted by Denise (Brooklyn, New York) on 08/10/2008

I just started taking 1000mg of msm with 1000 mg of vitamin c and GSE to treat my melasma but today my third day I am feeling kind of strange, anxious, restless and nauseos I dont know much about this supplement and am a little concerned. As much as i want to get rid of the melasma my health is first does anyone know if this passes I already suffer from insomnia and this is making it worse. Would the vitamin c and GSE work on its own?

Posted by Sherry (Jacksonville, North Carolina) on 11/27/2007


re: Side Effects of MSM --

I am so grateful to God for this forum. I can totally relate to DL from CA, that posting is almost a total duplicate of what I just recently experienced. I had been having constant pain in my legs and feet for over a year and had, had my fill. I did some research and came across the MSM. I was also diagnosed with osteopenia about the same time, so I decided to try it.

Two night ago I had my son take me to the ER, I was having a lot of what's been described here concerning the heart beating weird, anxiety(I guess) because I don't know how else to explain how I was feeling, shallow breathing, heaviness of chest etc. All this had been going on for some time and I normally could meditate on scriptures and it would go away, this night was different. My jaunt to the ER, showed irregular heartbeat, palpitations to be exact. However, all of my blood work came back normal, showing no previous heart attacks or heart disease. I have been referred for a stress test. I am going to discontinue my use of MSM and see what happens. I will keep you posted as to what happens after I am no longer taking this product. Oh yeah, one of the other effects is headaches. I also started getting headaches that wouldn't go away. I sorta fluffed that off figuring it was a sinus thing, however, these aren't sinus area specific. So, I'm thinking this is all related. Time will tell.

I am very happy for those folks that this works for. Of course, everybody's metabolism is different, so what works for others may not work for someone else. Anyone else that may have related info. that would be helpful to my situation please feel free to e-mail me. God Bless

Replied by Michele

I went to the ER too. MSM was helping me with hair loss and arthritis. Then I had chest pains and started taking a beta blocker. I overdosed and went to the ER. I had pains seemingly in my vein in my neck. I thought maybe I was experiencing a blood clot. I went to the ER 2 more times before I made the connection.

Anxiety, Caution for Pets

1 User Review

Posted by Deirdre (Ct) on 08/28/2020

Thank you for your great post on MSM, Art!

I think people do need to be very careful when they take MSM orally. I have taken it in the past and it caused anxiety and this sensation of pressure on the heart that was intense! I think that is a common side effect for people starting out on MSM.

Turns out you also have to be equally careful with dogs too! I gave a very small amount to my dogs in their dinner recently to help with arthritis and the next day, one of them wouldn't stop whining all day. He was clearly feeling punk from the supplement. No more of that! After 24 hours it left his system and he was back to his happy old boy self.

I will have to try it topically (on myself, not the dogs) and see if has the same side effects.

Replied by Rsw

Hi Deirdre,

Recently, my husband was having pain in his golf hands, and he read that MSM could be helpful. I told him I had some powder and he is using it with good results. However, when I got it out, I have written in black magic marker, “Not for RW! Allergic! Do Not Take.” I am allergic to sulfa medicines, and I think this is the reason I can't take MSM. It is the only supplement I have marked with a warning. I honestly can't remember what happened, but it may have been breathing or anxiety problems, but must have been bad for me to label it that way. It seems to work well to relieve pain for many people.

Replied by Art
1945 posts

Hi Rsw,

You can be allergic to sulfa drugs and you can be allergic to an organic sulfur like MSM, but they are two different allergies and having one does not mean that you also have the other.


Replied by Rsw

Hi Art,

There must be something in both that makes me feel terrible, sometimes with breathing problems. I also noticed a long time ago, as did my family, that if I had a glass of red wine, I could count on getting very congested afterwards, we thought possibly from the sulfites. I try to stay away from anything that contains any of those words.

My husband's hands were about the same, but he hadn't used the hand cream very long before he read about the kidney info. He almost died when he was a child from nephritis, and he has some kidney numbers that aren't optimal now, so he is hesitant to try something if he reads anything adverse.

Thank you for the info on several topics. I will post on the LP later. I am trying your homeopathic back treatment at the moment. I have had back pain with gardening or cleaning since I hurt my back years ago while shoveling and spreading a truck load of mulch. Not sure it is stenosis, but thought it couldn't hurt. I will take it until January or February, at least.

So good to read your posts with such good documentation. You give so many people hope with your research!

Anxiety, Dry Skin, Cold, Panic

1 User Review

Posted by Ana (Germany) on 09/27/2022

I have been taking MSM for 2-3 months. From the beginning, I had strong side effects, but I figured it was just the initial worsening of the symptoms. I was very excited, suffered from insomnia, my skin became increasingly dry, I developed severe dryness lines, my body was downright cold, my hands and feet tended to have a bluish/black discolouration.., Feeling dry in the throat.., fears, panic.. Now 6 months after stopping MSM, I am still having side effects and my skin has not fully healed.

I appreciate any feedback or help

Replied by HisJewel
(New York)

Hi Ana of Germany,

I do pray you are feeling much better today.

I am only a seasonal MSM user. As the weather gets cold and my knees remind me that they have feelings too, I mix 19 or less tablespoons in a gallon of water. I also take at least 1000mg of Vitamin C. I drink at least 8 ounces a day. By the time that I have finished the second gallon I am ready to take a break, I may or may not use it again that winter unless my bones act up. The only side effect I noticed when take MSM is the headache, which felt more like a dull massaging. I gladly put up with the headache a few weeks so I could walk straight. I did not know about taking molybdenum until now, and I plan to buy it.

I am sure you have checked Earth Clinic's MSM Side Effects Post,

Some of the suggested supportive supplements for better results with MSM that are reported on EC posts are:

Vitamin C, Omega 3, Magnesium, Activated Charcoal, and Molybdenum and a few others, read them again, you often see mentioned on Earth Clinic, "start low or slow" and skip a few days each week.

About Molybdenum Read Here:

Ana, also for a leg infection that has spreading bumps or shingles bumps the answer for me was "salt." I prayed and as I awoke that morning I heard "salt." So I took about a teaspoon of Arm and Hammer's Baking Soda and a pinch of salt and put just a few drops of water in it to make it paste enough to spread and not run. I put it on at night and washed it off in the morning. I did that a few nights.

The bumps dried up, and the sores healed, the color of my leg is the same as the other. "My legs are beautiful!" Once again, your skin may be very sensitive so use caution.

What works for one person may not work for another so pray.

And please think positive, "I shall recover good health."



That is a massive dose of MSM. According to a study I read, the large dose for arthritis is 3 grams. A low dose is 500ml. 19 tablespoons is 57 teaspoons. One teaspoon is 5.5 grams. So, 19 tablespoons is 313 grams of MSM. I'm not sure how long it takes you to drink that gallon, but that's high-dose MSM for over 3 months.

Replied by Russia
(Gaborone, Botswana)

Hey Ana, I started taking MSM 4 weeks ago. I had severe system parasitic infection for over 20 years. Anyway, one of the last cleansing processes I needed to do was clear the toxins left in my body by the dying parasites. Enter MSM. I started adding it to my juices and after a week I had slight pain in my head (my brain to be exact). Took two weeks and I had insomnia. Then I had itching all over my body.

3 days ago, I learned that when you take MSM you have to take hot water baths since the toxins released can be sent to the skin. I did, and all the itching stopped. I simply add sea salt to my bath - about 2-3 tablespoons at night. I find it very relaxing. For those worried about low molybdenum levels try eating brazil nuts if you are not allegic to them. One or two per day has lots of molybdenum.

Try taking the MSM with a blended juice of beetroot, carrot, cabbage (celery, if you want), apple and a bit of spinach or other green leafy veges (not a lot). The chlorophyll in the greens provides magnesium too.

I feel good. I have energy and can exercise well - started calisthenics at age 49! I sleep well too. The pain in the brain has gone. I had itchy eyes for a day or two and that stopped too.

Other things I take include broths of bone, vegetable, fish and chicken - I mix them altogether in a cup. Maybe the entire combo potentiates each other, I don't know.

Anxiety, Insomnia

1 User Review

Posted by Cheryl (Philadelphia ) on 05/06/2017 2 posts

I have had insomnia for a long time. I currently had it under control when put on nature throid for Hashimoto's. I also take sleep mess which weren't really working before. Then I started MSm and started with 1 gram and increased by a gm/ day for 10 days. Fine until the 10th day when I started to become anxious and couldn't sleep and had a massive headache for 3 days. I cut back to 1gm and the headaches and anxiety went away but I still have the insomnia. Don't sleep at all for 2 nights and 3rd night sleep 3-4 hours. Thinking of stopping the MSm for a few days to see if it helps the sleep. I was using the MSm because I have chronic neck pain and some back pain and most recently injured my rotator cuff and want to avoid surgery.

Bladder Irritation

1 User Review

Posted by Stephanie (Oregon) on 02/12/2021

Hello, When I take MSM, 1000 capsule, I start getting what feels like a UTI, doctor finds no infection. I feel this must be some reaction to MSM. Has anyone else had this sort of reaction and how did you cure it? Thank you

Blood Pressure

1 User Review

Posted by Sherry (South Africa, Cape Town) on 11/29/2021

Good morning, I have chronic pain (fibromyalgia) and I started taking Threshold Real MSM last Friday. Since I've started taking it, I found that my BP spiked up considerably. I have hypertension 2 and it's usually under control. I'm going to try and take only 1 a day and then see if there is any difference because I'm not even sure if it is because of Threshold tablets.

Body Aches

1 User Review

Posted by Jas (Plano, Texas) on 08/11/2022

MSM SIDE EFFECTS: I accidentally skipped a dose and my body aches are better and no leg cramps... those were severe and nightly and concerning. Have been on normal dose for weeks... but forget it... am done.


1 User Review
3 star (1) 

Posted by Alex (London, England) on 07/05/2009

Better But With Side Effects

I have just started taking MSM for IC cystitis. I feel an improvement already but have come out in big spots over my head and neck like boils. Has anyone else experienced this? Is this part of the detox? Love to you all Alex


1 User Review
4 star (1) 

Posted by Rsw (Oh) on 01/23/2017


I have been reading about the many health improvements that can come from taking MSM, so I ordered some 100% OptiMSM Silicon Dioxide. I had read it could help with muscle pain, stress, seasonal allergies, sleep, etc, and I did notice that a couple of hours after taking 1/4 tsp., I could breathe through both sides of my nose, not usual for me. However, at the same time I began coughing, which I thought was a fluke.

The next day, I took another 1/4tsp. and the same thing happened. Clear nose, increased coughing, until I woke up this morning with a lost voice, much coughing and tightness in the chest. Has anyone else had a similar response?

I have no temperature, so I am not sick. I was pretty much unable to understand the article that Art posted, (my lack of knowledge, nothing against the article, Art) so if that was a warning, please post in simple terms so I will understand.

Could this be an allergy to MSM? Maybe just a fluke?

I also want to let people know that I stopped taking my LDN for all of December in order to try Daisy's recommendation for non-alcoholic Essiac tea tonic, (which I feel helped to detox my system, but did not alleviate the Lichen Planus as it did for her), and I have been very achey, and feeling less well than normal. I will not be doing that again!

I didn't realize how much better I felt all the years I have used it, and I can't remember even having a cold in over six years that I have been taking it. I am thinking about trying the GAPS diet soon to see if I can rid my body of these autoimmune problems.


Have you looked at the feedback on the MSM Side Effects page here?

Chest tightness is one of the reported side effects.

Replied by Rsw

Thank you, Earth Clinic. I looked over all the MSM comments, and noticed several people say they were unable to take MSM because of a sulfa allergy, which I also have. This coughing and chest tightness is actually the same symptoms I got (only worse) when I was prescribed sulfa pills for a throat infection a long time ago. I was under the impression that sulfur was different from sulfa, but there may be some crossover. Although many people seem to benefit from MSM, I don't think it is going to work for me. So happy you directed me to those comments! Thanks!

Replied by Wendy

Sulfa is not the same as sulphur. Two completely different things. When they say "sulfa allergy" it usually involves rx drugs. Sulphur is a very common component to food in low amounts, so it's unlikely one would have a sulphur allergy.


1 User Review

Posted by Joanna (New York, New York) on 10/25/2007


I started taking 2 grams of MSM per day for about 9 days (NOW Foods brand in capsule form). As soon as I swallowed a capsule, I became excessively thirsty. I'd even wake up in the middle of the night to drink 2 full glasses of water. I perspired much more (perhaps from all the water I drank), which didn't bother me because I liked sweating more in the sauna. I got pains in my body, especially in my arms and hands - I felt like I was getting arthritis/tendonitis, which was weird because I thought MSM was supposed to help if you have that. My bowel movements increased from 1 per day to 4. At night I'd notice my heart was beating fast. I can usually walk for miles but I got really scared when I found I had trouble walking fast and breathing well on a fairly short walk. I was searching the web for allergic reactions to MSM but couldn't find any. The only other supplement I was taking at that time was 50mg of Ubiquinol (CoQ10). So I stopped taking both. The thirst and breathing/heart problems went away fairly fast, but the pains in my arms lasted a few weeks. Since the time I stopped taking it (probably 1.5 months now), I've been getting sharp pains in my upper abdomen (left and right sides), which have been slowly getting better.


2 User Reviews

Posted by George (Melbourne, Australia) on 08/28/2010

Side effects: Insomnia and severe depression after taking msm for 3 weeks.