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

| Modified on Feb 17, 2024
How to Deal with Side Effects
Posted by Anne (Vancouver, Bc) on 06/08/2012

I had been suffering with horrible muscle pains for a few years. So I started to read on what would help this pain. I started to take MSM and the pain I endured was worse but then.. read on to find out what happened.

MSM can and will reawaken your previous injuries. When I first started taking MSM I was in horrible pain.. So I stopped taking it and the pain went a way. Then I read that MSM detoxifies the body and will reawaken old injuries.. That you need to keep taking the MSM until the pain is gone (usually 2-3 weeks) So I started to take MSM again and the same pain returned. I had a horrible two weeks. After that the pain was less and less. That moment when I woke up and there was no pain at all I was in disbelief, as I was told by my Doctor's I would always suffered pain.. So I say.. If this causes pain, it means its cleaning out your system so drink lots of water while you are taking it and know that it's getting rid of that pain for good. :) A usual dose to start is one three times a day.. Work up to two three times a day. Of 1000mg each. Best of Luck all

Bladder Irritation
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

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.

Posted by Zmerrill4361 (Upstate, Ny) on 04/29/2016

Here is an update for any interested. I went off it for a few days to stop going through detox and purchased the MSM powder with no additives, then went from 1000 MG each morning and added 1000 MG to the regiment every week till where I'm currently at (8000).

But then I added some more supplements.

Since I work overnights and rarely see the sun I started taking vitamin D3 and K2 as I hear they are a good combo and milk thistle since the MSM detox your liver and kidneys. Also I'm taking Rhodiola for stress. I still take the blood pressure meds but its as low as its been in years and off the anxiety all together.

So thank you for all your advice

Kidney Stones, Long-Term Reactions
Posted by Rick (Newmarket, NH) on 10/16/2018

Initially, MSM was the most profound remedy I had ever experienced. It gradually but successfully treated my chronic prostatitis, tendinitis, even substantially improved depression symptoms I'd lived with for a decade.

After taking 2-3 grams for almost 3 years, however, it riddled me with imbalances and complications that I have yet to recover from. initially I started passing kidney stones- not realizing the MSM could contribute to this. After reading of a few similar cases online, I stopped taking the MSM and had a brutish withdrawal period.

I broke out in full hives on my back, fever, etc. after the withdrawal, all of my original symptoms returned, but with a twist. Over time I became similarly sensitive to most anti-inflammatory herbs/nutrients. I can't even take fish oil without having reactions. My kidneys behave irregularly, I have cardiovascular involvement, and more recently significant adrenal dysfunction. I suspect I imbalanced something nutritionally from taking the sulphuric, but i've had little to no luck finding a combination of nutrients to restore the balance. Please use caution with MSM, and even if you find it to help you. PLEASE take regular breaks when using it. Do not stay on it long-term. It's been over a decade since I stopped, and I'm not certain whether I'll ever get my life back completely.

Posted by Art (California) on 05/18/2023 2080 posts

You are quite welcome, Dimitra!

Do you have a diagnosis for your condition that was caused by the motorbike accident? If so, you should post it as you are likely to get many suggestions that may help.

On a related note and not knowing what your diagnosis is Boswellia Serrata Extract may help as it is an anti inflammatory and is generally well tolerated. There are several forms of it, but you would definitely want an extract form. Here is a link to a typical product :,aps,149&sr=8-5

Another consideration is topically applied mag oil spray. Here is a typical product:



Depression, Exhaustion, Mental Fog
Posted by Mama to Many (TN) on 07/18/2022

Dear Victim,

Do you have a local person that can help you, a friend to help you sort through things and give you wise counsel?

I hesitate to recommend any supplement, as you are wise to take a break - activated charcoal though, may help to adsorb and detoxify your system.

Plenty of water, rest, sunshine, fresh air and light exercise seem in order.

Please see this page of wellness ideas. They are mostly not things to do internally. I am wondering if cold shower therapy mentioned in the article would be of benefit to you.

Please let us know how you are doing. Remind yourself of my mother-in-law's wisdom - This will pass.

~Mama to Many~

Extreme Detox Symptoms
Posted by Orion (Columbia, Mo) on 04/26/2018

I use MSM with Vitamin C as part of an anti-cancer protocol. It gives the body's cells more oxygen which kills cancer and other fungi, namely fungal candida. Both of which I suffer from.

I consumed 3g of MSM and 24 hours later I'm still terribly ill. I have a lot of pressure and pain behind my left eye, my neck, migraine, extreme weakness, very nauseous, dizzy. I've taken 2 pills of aspirin and then 3 hours later 2 pills of ibuprofen, and by the 5th our I reached a plateau of moderate pain, but weakness and nausea stayed the same.

This is known as the Herxheimer reaction.. So if anyone is experiencing these adverse symptoms from MSM, it means you were already sick and just didn't know it. The MSM is actually killing the cancer/fungi which is releasing toxins (in my case MASSIVE amounts of toxins). Consequently you'll have to use smaller doses to minimize the amount of toxins your body has to cope with. Some of these toxins are not easily removed, like acetaldehyde (which also causes cancer lol). Molybdenum amino acid chelate can help remove it.

Extreme Detox Symptoms
Posted by Anon (Canada) on 04/27/2018

Hi Orion -

I wish you the best of luck on your health journey. My husband has just started the MSM/Vitamin C protocol too (he has Stage IV colon cancer and is suffering from cachexia).

This is what he is doing based on the Cancer Tutor protocol:

I apologize for the long post!

How to make “MSM Water”

To make “MSM Water, ” take a gallon jug of water which has ZERO chlorine in it. Use either purified water or tap water that has been out of the faucet for at least an hour before using it.

Put 16 TABLEspoons of “Organic Sulfur” (MSM) into the one-gallon jug of water.

It may take an hour for the organic sulfur to totally dissolve. To speed up this process shake the gallon jug every few minutes.

Once the organic sulfur has totally dissolved, and you do not see any crystals in the bottom of the jug, the “MSM Water” is made.

A person could put into the gallon jug 30 or 40 drops of “Cell Food” (a trace mineral supplement) as a way to get some trace minerals into the body. This is recommended but not required.

Do not refrigerate it, let it sit at room temperature.

Adding lypo-spheric vitamin C to the “MSM Water”

While the MSM water by itself may be able to revert cancer cells into normal cells; it is best to be on the safe side and add other things to the protocol that can definitely revert cancer cells into normal cells.

Thus, Lypo-Spheric Vitamin C, a high quality, very gentle brand of Vitamin C, has been added. Vitamin C kills microbes and the portion of the MSM that converts to DMSO (and perhaps some of the MSM itself) will “open” the ports of the cancer cells to allow microbe-killing substances inside the cancer cells.

A person cannot start out with high doses of MSM water because their stomach will not be accustomed to drinking it. Thus, instructions for the use of MSM water are more complicated than might be expected.

(NOTE #1: Vitamin C should always be taken 1/2 hour AFTER MSM. This allows the MSM 1/2 hour to open the ports of the cancer cells for the Vitamin C to enter.)

Doses of MSM Water (and build-up) – For an adult

Start with 1 TEAspoon of MSM water to test for allergies.

Two hours later you can start the “build-up.”

Day 1 build-up:

Take 4 TABLEspoons of “MSM water” (the “MSM Water” comes from the gallon jug you just made).

At this point check for nausea or rashes caused by the MSM water. One-half hour later take 1 gram of Lypo-Spheric Vitamin C,

Three hours later take 6 TABLEspoons of MSM water followed 1/2 hour later by 1 gram of Lypo-Spheric Vitamin C,

Three hours later take 8 TABLEspoons of MSM water followed 1/2 hour later by 1 gram of Lypo-Spheric Vitamin C.

That is all for Day one. The first day achieved two purposes. First, was to get your stomach used to taking MSM. Second, and just as important, was to avoid too much Herxheimers. Herxheimers, although it is harmless, can make a person very sick and can scare a person from taking more MSM. It is caused by a massive die-off of microbes in the bloodstream. When the microbes die off they release toxins. If there are too many toxins in the blood it can make a person sick and/or cause “brain fog.”

Also, note that a person should drink plenty of purified water or “ozonated” water or “ionized” water or distilled water every day.

Day 2:

1) Take 8 TABLEspoons of MSM water (ALWAYS FROM THE GALLON JUG), then, 1/2 hour later, 2 grams of Lypo-Spheric Vitamin C,

2) Three hours later take 10 TABLEspoons of MSM water then, 1/2 hour later, 2 grams of Lypo-Spheric Vitamin C,

3) Three hours later take 11 TABLEspoons of MSM water then, 1/2 hour later, 2 grams of Lypo-Spheric Vitamin C.

Day 3 and thereafter (i.e. ongoing dose):

1) Take 12 TABLEspoons of MSM water, then 1/2 hour later, 2 grams of Lypo-Spheric Vitamin C,

2) Two or Three hours later take 12 TABLEspoons of MSM water then, 1/2 hour later, 2 grams of Lypo-Spheric Vitamin C,

3) Two or Three hours later take 12 TABLEspoons of MSM water then, 1/2 hour later, 2 grams of Lypo-Spheric Vitamin C,

4) Two or Three hours later take 12 TABLEspoons of MSM water then, 1/2 hour later, 1 gram of Lypo-Spheric Vitamin C.

5) Two or Three hours later take 12 TABLEspoons of MSM water then, 1/2 hour later, 1 gram of Lypo-Spheric Vitamin C.

The Cancer Tutor also mentions LIPH but my husband isn't taking that. He is on so many supplements and protocols right now that we have to limit what we do.

Also, this protocol is very expensive when you use so much Lypo-Spheric Vitamin C but there are instructions on the Internet on how to make your own.

Good luck!

Digestive Problems
Posted by Darlene B. (Us) on 08/01/2017

I have ibs and for some reason after supplementing with msm for about a week, I start to suffer a lot of bloating, gas and eventually diarreah. It seems to need to build up in my system for about a week before the symptoms begin. I stop for several weeks and then try again and again the same thing happens.

Digestive Problems
Posted by Joannaelizabeth123 (Los Angeles, Ca) on 05/16/2017

Per your article on MSM, asking to hear from people using it.. here I am! I thought to take it for flexibility. I'm in my 40's and I do circus classes for fitness, and I'm strong but more stiff than in my youth. Well, yesterday I took Jarrow Formulas powder (1/2 tsp) with a meal and felt fine. Today I took the same, but about an hour after my meal... and my gut aches! I feel like I've got acid happening... Now I see many websites say "intestinal discomfort" is a common side effect, but NONE of them suggest what I can do while experiencing it. I hope to never, ever have this sensation again (if I try it I'll do it with meals and take even less) but if it happens again, and for all the other sufferers, what the heck can we do???


Posted by Madeline (New York) on 04/08/2021

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.

Anxiety, Dry Skin, Cold, Panic
Posted by HisJewel (New York) on 10/01/2022

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."


Anxiety, Caution for Pets
Posted by Art (California) on 08/29/2020 2080 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.


Posted by Charity (Faithville, Usa) on 10/27/2017

Msm is a sulfur the body uses and gets depleted as we age. I use it daily . When you use it, it depletes other things it works with to restore youth and vitality and I use it for pain control. I know it depletes C and molybdenum, so if you use it and throw other nutrients off balance then your body produces histamine( hives is one sign of this) to let you know you are out of balance.

Posted by Charity (Faithville, Usa) on 07/25/2016

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.

Posted by Nikki (Usa) on 09/17/2015


In a nutshell, MSM is amazing, but not for everyone. It erradicates my allergy symptoms at "moderate" doses 5grams/day but I have to take much more for relief from spine pain. However when I got a routine of taking 1 tbsp (Crystal form which by volume is a lesser dosage than fine powder) once or twice a day. My skin looked great (more youtheful but without the blemishes) and my body was starting to feel flexible with much less pain. Sadly, I had headaches daily. The migraines I had grown to expect came with the same frequency as before, but I had this other less intense but certainly very unpleasant headache day and night. Perhaps I was detoxing, but it went on for two months and I had to stop MSM to see if it was the culprit. The headaches cleared up in a few days. When I went back to a moderate dose of 4-5 grams per day, allergies were mostly erradicated and I didn't have a daily headache, but the back/neck pain and inflammation in general didn't seem very much improved. I have just read the notes here on MSM posibly depleting Molybdenum so I will research this and try taking Molybdenum as well, if it appears safe to do so. I believe MSM is a useful detoxifier and might be especially helpful to detox after vaccination (at any point after, but certainly the sooner the better).

I appreciate links to research and notes on these matters as well as personal experience of MSM and it's ability to cause headache (indirectly or however).

Posted by Alijawales (Wales, Uk) on 11/08/2013

MSM has triggered severe insomnia in me, but it's because it is dealing with parasites in my body. They are always much more active at night and the MSM is driving them nuts. Hopefully this will pass.

If MSM is keeping you awake, it may not actually be the MSM that is the real issue...

Also, the body does its housekeeping at night when we are resting and not diverting our energy to other things. As Sulfur is one of the elements that helps the body detox, and absorb nutrition better, which helps in the healing process, it is very likely to trigger rashes, headaches, nausea, diarrhoea, coughs, colds, etc., in fact anything that could be used as a route to get unwanted matter out of the body.

We assume these things are 'illnesses', but they are just the body's way of cleaning itself. We go and get medications to suppress these processes, often driving toxins even deeper into the body instead of giving the body the tools, and the recognition for its amazingly designed ability to heal itself.

Hair Loss, Fatigue
Posted by Art (California) on 05/14/2022 2080 posts


I forgot to mention that fatigue can be a symptom of MSM, but maybe topical application may allow you to avoid that symptom.


Posted by Russia (Gaborone, Botswana) on 10/08/2022

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 Joyce (Manteca, Ca Usa) on 04/13/2013

I was so happy to find this site. I took 2 tsp MSM for 2 days and 1/2 tsp for 2 days and 3 weeks later I'm still having reactions. I wake in the middle of the night with my body buzzing and I'm having headaches (which I've never had in my life). My energy level is very low. I'm 75 and very healthy otherwise; I'm still working as a substiture teacher. I'm allergic to sulfa and that may be the problem since some others on the site said they were unable to take MSM because of that. I was really hoping it would help with my shoulder problems. I have a damaged rotator cuff (inoperable) from hairstyling for 34 years.

Posted by Michele (TX) on 05/09/2021

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.

Joint Pain, High Blood Pressure
Posted by SHIRLEY (FL) on 10/11/2022

2 weeks on msm. Joint pain bad and high blood pressure. I am taking 1/8 teaspoon msm pure flakes.

Depression, Exhaustion, Mental Fog
Posted by Madey (Idaho) on 07/20/2022

This is what I would try:

1. Charcoal- take activated charcoal on an empty stomach with a large glass of water
2. Alpha lipoic acid- removes heavy metals
3. Molybdenum- helps the body utilize sulfur
4. iTeracare device- emits terahertz frequencies and greatly improves circulation and unblocks sticky blood cells and clumps. Charge water and drink. Use device directly on forehead and the rest of your head for 15-20 minutes daily.

Good luck and write back with questions, feedback, and what ended up working for you.

Hair Loss, Fatigue
Posted by Art (California) on 05/14/2022 2080 posts


It seems reasonable to stop the FGDE for three months to see if your reported symptoms reverse. Three months is a reasonable amount of time when testing effects on the hair because it grows slowly. It clearly does not seem to be working for your hair at this point anyway. There are silica containing supplements which may also be effective for your hair and nails if it turns out the FGDE is the cause of your problems.

As far as the MSM, it can be used topically as a cream or spray that you can make yourself and may be similarly effective as oral consumption. You can spray it directly on the affected joints. Usually 4 to 5 grams of MSM per ounce of distilled water is what I have found useful.


Blood Pressure
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.

Anxiety, Caution for Pets
Posted by Rsw (Oh) on 08/29/2020

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!

Extreme Detox Symptoms
Posted by Fiona (Kilkenny) on 05/12/2018

I believe this is the most accurate take. MSM is wildly powerful: many of us looking for wholistic "cures" are already quite unwell and the detox process is no joyride. Take Vit C, start small with the pure MSM powder (and v.early in the morning) and drink plenty of water throughout the day. Add some physical movement, again start out gently, and enjoy the road to recovery!

Posted by Rvee (Finland) on 02/28/2017

I have used MSM powder(Doctors Best) two periods. I started with a small dose 1/4 teasp to 1 tablespoon.

It helped my back pain but what really scared me off was excess hairloss and PMS. I´m not kidding, I lost both periods on MSM half of my hair. I was really sceptical it was MSM what was causing those, but had to believe since it happened twice.

I created very sore breasts and I act like a maniac before menses so I had to get rid of MSM.

Now I´d like to know, since there is so little information of MSM and women hormone balance, what is actually causing this? My own opinion is that women with oestrogen dominance suffer the most of MSM. MSM might somehow decrease progesteron levels on pre-menopausal women. I found earlier a link about the progesterone levels and MSM, but I lost it.

Do you have any information about this?

Posted by Zach (Upstate, Ny) on 11/14/2015

I recently started taking MSM (about 3 days ago) first day I took 1000 mg tablet on my way home from work (I stopped at a local supermarket at 5:15 am cause I work overnights) and had insomnia that night... should have read not to take it before bed. So I tried it the next day 1000 mg 2x's. Felt exhausted, slight headache and I drank distilled water about half a gallon.

Next day I took 3 tablets (1000 mg each) finished the other half a gallon of distilled water and had same symptoms. I woke up after that my eyes were pounding in my skull worse headache and exhausted more than usual. I want to take advantage of the benefits but I can't do 2 weeks of the detoxing.

Could it be I got a low quality (wegmans brand MSM), taking too high a dose (i weigh 230 6'5 male) , or is it just not for me? I take atenolol for pre hypertension celexa for my social anxiety, and aderal for adhd. my anxiety gives me slight ocd like behaviors as far as "ticks" go. I have zero emotion on the meds so I'm trying to get off them.

Posted by Mary (Tn) on 04/23/2016

Sounds like your dosage is too high too soon. Headaches are a sure sign of that. Start low, and add dosages week by week. If you get headaches or any undesirable affect back down on dosages for awhile then proceed to desirable dosage.

Digestive Problems
Posted by Shelleyjr (Albuquerque, NM) on 04/01/2014

I started MSM 5 days ago for Osteoarthritis pain and have had terrible headaches and bloating/gas. I got molybdenum yesterday and while it cured the headache, I still have tummy issues. (Arthritis is already better! )

I am taking 4 Doctor's Best MSM 1000 mg/1 gm capsules split between am and late afternoon. I took 450 mcg of molybdenum this morning with 2 gms of MSM and did the same this afternoon. Again no headache but my stomach feels bloated/gassy.

Health History;

I had hair analysis done a while back and each time it showed very high amounts of calcium and copper. (I had a copper toxicity using a skin care product on my clients. I absorbed a lot of copper through the palm of my hands doing facials.) Since then I have been doing a lot of detox's over the years.


I take Iodoral iodine, K2 and D3, CoQ10, boron/borax, tart cherry capsules for the OA and gout, and topical magnesium.

Today I have taken 900 mcg of molybdenum and feel it is working somewhat but not to the extent that Dr. Ben Lynch says on his podcast. Which he states molybdenum will eliminate bloating/gas associated with MSM. Also, in Dr. Lynch's podcast he list all the symptoms of a molybdenum deficiency which I answered "yes" to all. Since I am not worried about depleting my copper levels should I take more? And has anyone taken molybdenum in high doses over 950 mcg?

Thank you for any insight on high dose molybdenum.