MSM Sulfur: What It Does, How Much to Take, and What to Know First

This page provides general educational information. It is not medical advice, and it does not provide a diagnosis or a personal course of care.

What MSM Sulfur Is

Methylsulfonylmethane is a small organosulfur compound. Its molecular formula is (CH₃)₂SO₂, and around a third of its weight is elemental sulfur. It occurs naturally in trace amounts in a range of foods, and in the wider environment as part of the sulfur cycle that moves sulfur between oceans, atmosphere and soil.

You will see it sold as “organic sulfur,” “MSM,” “MSM sulfur,” and “dimethyl sulfone.” Those are all the same compound. The word organic here means organic in the chemistry sense — carbon-containing — which is a different claim from organic in the agricultural certification sense. Worth knowing when you compare labels.

MSM and DMSO

MSM is closely related to DMSO, dimethyl sulfoxide, and is in fact what DMSO oxidises into. That relationship is why they get discussed together, but they are not interchangeable. DMSO is a solvent with a well-earned reputation for driving substances through skin and for producing a distinctive garlic taste and body odour. MSM does not behave that way. If you have read something alarming about DMSO, check whether it actually applies to MSM before you extend it.

What Sulfur Does in the Body

Sulfur is not a trace element in the way selenium or chromium are. By mass it is among the more abundant elements in the human body, and it is structural rather than catalytic — meaning it is built into things rather than just helping reactions along.

Two places it matters most:

• Keratin. Hair and nails are largely keratin, and keratin is rich in cysteine, a sulfur-containing amino acid. The disulfide bonds between cysteine residues are what make nails rigid and hair resilient. Human hair is roughly 14% cysteine; the nail plate is about 10% sulfur by weight.
• Glutathione. The body’s principal antioxidant is a tripeptide built around cysteine. No sulfur, no cysteine, no glutathione.

Sulfur also appears in collagen’s supporting structures, in the amino acid methionine, and in a range of enzymes. This is textbook biochemistry rather than a claim about any supplement, and we present it that way.

What the Human Research Actually Shows

Here is where we try to be more useful than most pages on this topic, which tend to list every study ever conducted without distinguishing between them.

The best-documented human work on MSM covers joint comfort and exercise recovery, with a smaller body of work on skin, hair and nails. Two studies on that second group are worth naming because they are specific and checkable:

• Hair and nails. A double-blind study published in the Natural Medicine Journal in November 2019 gave 63 subjects either 1 or 3 grams of MSM daily for four months, assessing hair and nail condition by expert grading and self-assessment. Both doses produced measurable improvement, with the 3 gram dose working faster.
• Skin. Muizzuddin and Benjamin, writing in the International Journal for Vitamin and Nutrition Research (2022; PMID 32083522), ran a two-part study on visible skin ageing, including a 63-participant arm comparing 1 gram against 3 grams over 16 weeks.

One caveat we would rather state than have you discover: both of those studies were funded by an MSM manufacturer, and they disclose it. That does not make them wrong — industry funds most ingredient research, and these were properly conducted and peer-reviewed — but it is context you are entitled to when weighing them.

For a broad overview, the reference most people should start with is Butawan, Benjamin and Bloomer, Methylsulfonylmethane: Applications and Safety of a Novel Dietary Supplement, published in Nutrients in 2017 and freely readable on PubMed Central as PMC5372953.

How Much MSM Should You Take?

Clinical studies have generally used somewhere between 1 and 3 grams a day, and the 2017 Nutrients review describes MSM as well tolerated at doses up to around 4 grams daily.

That is the research picture, not a recommendation for you. Use the serving size on the label of whatever product you have, and if you are considering something different, that is a conversation for a clinician rather than a website. We do not publish condition-specific dosing.

What Not to Take With MSM

This is one of the most common searches about MSM, and it deserves an honest answer rather than a confident one.

The truthful position is that documented drug interactions for MSM are sparse. It has GRAS status, it has been consumed widely for decades, and no significant interaction has been well characterised in the literature. Some references raise a theoretical caution around blood thinners, and some suggest avoiding alcohol on general principle with sulfur-containing compounds.

But sparse documentation is not the same as demonstrated safety in combination, and the honest gap is this: MSM has not been systematically studied against the medications most people are actually taking. Absence of evidence here is genuinely absence of evidence.

So: if you take prescription medication, mention MSM to your pharmacist. That is a free conversation and pharmacists are good at exactly this question.

Side Effects and the Kidney and Liver Questions

The side effects reported with MSM are mild and mostly digestive — some nausea, loose stools, or bloating, particularly when starting at a higher dose. Headache is occasionally reported. Starting low and increasing tends to reduce this.

People search specifically about MSM and the kidneys, and MSM and the liver. We are not aware of good evidence that MSM harms either organ in healthy people at ordinary supplemental doses. What we would say is that if you already have known kidney or liver impairment, the safe amounts have not been established for you specifically, and that is a question for your doctor rather than a supplement company.

The same applies during pregnancy and nursing, where the honest answer for most supplements is that the data does not exist.

Where Tarsul Fits

Tarsul is organic MSM sulfur combined with organic cream of tartar. Two ingredients, no fillers, no binders, no proprietary blend. We have run it out of San Diego since 2010. Our ingredients page has the formula details.

Frequently Asked Questions

What does MSM sulfur do for the body?

It supplies sulfur, which the body builds into keratin, glutathione and various proteins. The human research is strongest for joint comfort, exercise recovery, and the condition of skin, hair and nails.

What should you not take with MSM?

No major interaction is well documented. There is a theoretical caution around blood thinners. Because MSM has not been systematically tested against most prescriptions, the practical answer is to check with your pharmacist if you take anything regularly.

What is the downside of MSM?

Mild digestive upset at higher doses is the most commonly reported issue. Beyond that, the honest downside is that the evidence base, while real, is smaller and more industry-funded than the marketing around it suggests.

Is MSM safe for your liver or kidneys?

There is no good evidence of harm to either in healthy people at ordinary doses. If you have existing liver or kidney impairment, safe amounts have not been established and you should ask your doctor.

Is organic sulfur the same as MSM?

Yes. “Organic sulfur,” “MSM,” “MSM sulfur” and “dimethyl sulfone” all describe the same compound.

How long before you notice anything?

The hair and nail study measured over four months, with some changes appearing earlier. Anything structural involving keratin is slow by nature, because hair and nails grow at a fixed rate regardless of what you take.