test-MSM Side Effects: What are the Side Effects of MSM?
Food & Nutrition
MSM Side Effects: What are the Side Effects of MSM?
Amy Sunderman, MS, RD • March 17, 2018

MSM: Possible Side Effects and Dosage

Many supplement manufacturers claim to offer the “miracle supplements” destined to change your life in every way imaginable. It’s a lot of hype in some cases, but when it comes to MSM, there’s a lot of truth behind such claims.

Why? Well, studies considering the benefits of MSM supplements have found strong links to things like joint health, mobility and muscle health. Things that matter to all of us, regardless of age or current state of health. MSM promises to help us feel better, move easier and recover faster. So, it may not be a “miracle,” but it’s worth a closer look, including a look into the reported side effects of popular MSM supplements that are now widely available.

What is MSM?

MSM, or methylsulfonylmethane, is an organic sulfur compound synthesized for use as a dietary supplement. In nature, it’s found in small amounts in fruits, vegetables and grains.1 The MSM found in supplements and powders is a water soluble, odorless compound that delivers elemental sulfur to the body.

As one of the more abundant minerals found in the human body, sulfur is crucial for many different bodily functions. Your body can use sulfur to synthesize critical chemicals, form or repair connective tissues, metabolize certain foods and help the digestive system absorb nutrients from the foods you eat.

MSM is actually a natural byproduct of another sulfur compound: dimethyl sulfoxide (DMSO). MSM and DMSO provide similar benefits, but MSM is a more biologically available form of elemental sulfur, as your body converts DMSO into MSM.

Getting enough sulfur from diet alone is difficult for a few reasons. First, the modern American diet often lacks fresh fruits and vegetables that contain naturally-occurring sulfur. Second, the soil where produce is grown has become depleted of natural sulfur, which limits the amount of sulfur available for plants to absorb while growing in the ground. Finally, cooking can destroy the small amount of sulfur that is found in today’s produce, all but ensuring that diet alone isn’t a sufficient source of sulfur.

Why Do People Take MSM Supplements?

The most common uses for MSM supplements focus on joint health and reducing common aches associated with exercise or physical acitvity.2 Whether it’s a joint combination formula featuring MSM, glucosamine and chondroitin, an MSM powder added to a post-workout recovery shake or even an MSM liquid supplement, MSM’s main benefits revolve around promoting joint health and flexibility.

MSM Supplement Uses & MSM Benefits

MSM for Joint Health
MSM is often taken to help support joint health, promote flexibility and preserve collagen. Many clinical studies have been conducted on the benefits of MSM for joint health, with positive results.3,4 However, MSM is a dietary supplement and not a cure for chronic joint issues related to diseases that affect joints.

Skin Health and MSM
Research shows that MSM may help soothe skin and support overall skin health, plus help combat signs of aging and boost collagen production.3

Muscle Health, Exercise Recovery and MSM
MSM may help support muscles during workouts and help fight oxidative stress because of exercise.5

MSM for Immune Health
Studies suggest MSM may play a role in supporting immune response to stressors and combating related oxidative stress within the body.3

MSM and Hair Health
MSM supports both collagen and keratin, which are needed for strong, healthy hair.3

For more on the benefits of MSM, read MSM Benefits: Joint Health & Beyond.

MSM Dosage

For most of us, a single 500 mg serving of supplemental MSM each day provides an adequate supply of elemental sulfur to prevent deficiency, as well as support the normal production and maintenance of healthy connective tissues and beautiful, strong hair, skin and nails.

Potential MSM Side Effects

MSM is commonly supplemented in doses between 500 mg – 6,000 mg per day, and this range has a great safety record. Some studies and trials have involved higher intakes of MSM, but it’s best to stay well within demonstrated safe ranges unless directed by a physician.

Like any supplement, MSM powders, pills and creams may exhibit mild side effects in some users, especially at prolonged use of high doses. While direct evidence of MSM side effects is limited, a few may be worth monitoring and speaking with your doctor about should you experience them.6 One clinical study did report diarrhea with daily doses of 1500 mg.7 Dosages of 6,000 mg of MSM daily also had some reports of bloating.8 Some users have reported headaches that ceased when they stopped using MSM.9 For most adults who stick to the single 500 mg serving of supplemental MSM each day or within the common doses between 500 mg – 6,000 mg per day, side effects from MSM should be minimal or nonexistent.

Overall, MSM is very safe. Toxicity studies in animals have shown it to be as safe as pure water, and there are no reported allergic responses.1,2 That said, the above mild adverse reactions can occur with high doses and should be reported to your primary healthcare provider.

MSM Supplements for Joint Health

Here are the dosage recommendations for three of our popular MSM products:

Swanson Ultra MSM
This MSM supplement Provides 1 gram of TruFlex® MSM and can be taken 3-5 times per day. TruFlex® MSM is a unique, organic MSM formula that is biologically active for easy assimilation.

Glucosamine, Chondroitin & MSM
This three-in-one joint health formula contains 200 mg of MSM, 500 mg of glucosamine sulfate (from shellfish) and 400 mg of chondroitin sulfate. It can be taken 1-3 times per day with food and water.

Swanson Premium MSM Powder
MSM powder is a convenient way to get your intake of MSM, providing 5 grams of MSM per scoop to be used once daily. It mixes easily with water and juice, or add it to your favorite smoothie.

Let us know how you use MSM in the comments below!

Amy Sunderman, MS, RD, Director of Science & Innovation Registered Dietitan

About Amy Sunderman, MS, RD
Director of Science & Innovation, Registered Dietitian, Swanson Health

Amy is a registered dietitian, nutritionist and author with over 20 years of experience in the supplement industry. Amy is passionate about dietary supplements and the health benefits they offer. She enjoys working to find novel nutritional ingredients with strong clinical research behind them to drive innovation and provide health-promoting products to consumers.

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.


1 MSM (methylsulfonylmethane) Dietary Supplement. Medicine Net https://www.medicinenet.com/methylsulfonylmethane_msm-oral/article.htm

2 MSM (methylsulfonylmethane). WebMD https://www.webmd.com/vitamins-and-supplements/msm-methylsulfonylmethane-uses-and-risks

3 Methylsulfonylmethane: Applications and Safety of a Novel Dietary Supplement. National Library of Medicine.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5372953/

4 Effects of MSM on exercise-induced muscle and joint pain: a pilot study. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4595302/

5 Effect of MSM Supplementation on Exercise-induced Oxidative Stress. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5521097/

6 Glucosamine and Chondroitin Side Effects? Health Fully. https://healthfully.com/glucosamine-chondroitin-side-effects-3884228.html

7 Systematic review of the nutritional supplements dimethyl sulfoxide (DMSO) and methylsulfonylmethane (MSM) in the treatment of osteoarthritis. Science Direct. https://www.sciencedirect.com/science/article/pii/S1063458408000666#bbib37

8 Efficacy of methylsulfonylmethane (MSM) in osteoarthritis pain of the knee: a pilot clinical trial. National Library of Medicine. https://pubmed.ncbi.nlm.nih.gov/16309928/

9 The Miracle of MSM. By Stanley W. Jacob. https://books.google.com/books?id=QXXnCgcoDIAC

Updated 3/4/22