This article is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before making health decisions based on this content.
By BackToHealthTroy.com Editorial Team | Last verified: August 2026
In This Article
What MSM (Methylsulfonylmethane) Is
MSM is the common name for methylsulfonylmethane, also called dimethyl sulfone—a simple, odorless organic compound containing sulfur. Its chemical formula is (CH₃)₂SO₂. It occurs naturally in small quantities in many foods and beverages, including cruciferous vegetables (broccoli, cabbage), garlic, onions, legumes, nuts, seeds, milk, and eggs.
MSM has been available as a dietary supplement since the 1980s, when biochemist Robert Herschler filed a patent for its use as a nutritional ingredient. It is sold as capsules, powders, and topical creams, often in combination with glucosamine or chondroitin for joint support. The most common branded form is OptiMSM.
Unlike its chemical cousin DMSO (dimethyl sulfoxide)—which is used medically as a topical anti-inflammatory and solvent—MSM is a distinct compound with its own pharmacology, though the two are sometimes confused.
How MSM Works in the Body
Absorption and Distribution
When taken orally, MSM is absorbed into the bloodstream and can cross the blood-brain barrier, according to nuclear magnetic resonance (NMR) studies. Trace amounts of MSM are naturally present in blood and cerebrospinal fluid, likely from dietary sources, bacterial metabolism in the gut, and the body’s own sulfur metabolism.
Proposed Mechanisms
The exact biological mechanism by which MSM might reduce pain or improve skin and joint health is not fully understood. Several mechanisms have been proposed:
- Anti-inflammatory effects: Some researchers suggest MSM may reduce inflammatory signaling, though this has not been definitively proven in human studies.
- Sulfur availability: MSM promoters argue that many people are sulfur-deficient and that MSM provides bioavailable sulfur. However, no Dietary Reference Intake (DRI) for sulfur exists, and sulfur is abundant in protein-containing foods—making true deficiency unlikely in people eating a varied diet.
- Collagen and connective tissue support: Sulfur is a component of collagen and other connective tissue proteins, but whether supplemental MSM increases tissue sulfur content in meaningful ways remains unclear.
- Antioxidant effects: Some preliminary evidence suggests MSM may reduce oxidative stress markers, though this has not translated reliably to clinical benefit in humans.
What the Research Shows About MSM
Osteoarthritis and Joint Pain — Mixed Evidence
Osteoarthritis (OA) is the primary condition MSM has been studied for. A systematic review found small, methodologically limited trials suggesting possible benefit for knee OA pain, but concluded: “No definitive evidence that MSM is superior to placebo in the treatment of mild to moderate osteoarthritis of the knee.”
The evidence grade for OA is limited to preliminary. While a few small trials (n=20–100 per study) reported pain reduction or functional improvement with doses of 1.5–3 grams per day, design flaws and placebo effects make firm conclusions impossible. Larger, well-controlled trials are needed.
Skin, Hair, and Nail Health — Very Limited Evidence
The first rigorous study of MSM for skin was published in 2015. It involved only 20 women taking 3 grams daily and reported improvements in facial wrinkles, firmness, tone, and texture. A follow-up study from the same group (n=20) tested doses of 1–3 grams and also reported improvements in wrinkles, firmness, and skin hydration.
While these results are encouraging, the studies are small, had no independent replication, and lacked long-term follow-up. Evidence grade: preliminary. More research is needed before MSM can be recommended for skin health on a clinical basis.
Other Claims — Insufficient Evidence
MSM is marketed for many other conditions—immune support, muscle recovery, allergy relief, and general anti-aging. There is currently limited to no clinical evidence supporting these uses. Most claims arise from industry promotion or anecdotal reports rather than peer-reviewed research.
Forms and Bioavailability of MSM
Available Forms
- Oral capsules or tablets: Standard form, 500–1500 mg per serving
- Powder: Often mixed into water or beverages; allows flexible dosing
- Topical creams or lotions: Applied directly to skin; absorption is limited and not well-studied
- Combination products: Often paired with glucosamine, chondroitin, or collagen for joint support (combination benefit is not established)
What Affects Absorption
Oral MSM is absorbed reasonably well when taken with food or on an empty stomach. Unlike some nutrients, there is no major carrier protein or active transport mechanism—absorption appears to be simple passive diffusion. This means that taking very high doses is unlikely to increase absorption proportionally.
Topical forms (creams, gels) have unclear penetration into deeper tissue. MSM is sometimes added to topical products as a permeation enhancer (similar to DMSO), but whether it acts as an active therapeutic agent or merely a vehicle is not established.
Who Should Consider MSM and Who Should Avoid It
Reasonable Candidates
- People with mild-to-moderate knee osteoarthritis seeking adjunctive support (alongside physical therapy, weight management, and other evidence-based approaches)
- Those interested in skin health and anti-aging who have mild, isolated concerns and realistic expectations
- Individuals who have tolerated MSM well previously and believe it helps their symptoms
Who Should Be Cautious or Avoid MSM
- Pregnancy and breastfeeding: Safety data are insufficient; consult your healthcare provider.
- Bleeding disorders or anticoagulant use: MSM may have mild antiplatelet effects; use cautiously and under medical supervision.
- Sulfa allergies: MSM is not a sulfonamide, but people with severe sulfa sensitivity should consult a clinician before use.
- Severe osteoarthritis or significant joint damage: MSM should not replace evidence-based treatments (physical therapy, medication, injections, surgery).
- Those seeking a cure: MSM is not a cure for arthritis, skin aging, or any chronic condition; expectations should be modest.
Safety, Side Effects, and Drug Interactions
Overall Safety Profile
In 2008, the FDA designated OptiMSM (a branded form of MSM) as Generally Recognized as Safe (GRAS). This determination was based on safety data, not efficacy. Animal studies show MSM has very low toxicity, with an LD₅₀ (lethal dose in 50% of animals) greater than 17.5 grams per kilogram of body weight—extremely high compared to typical human doses.
Common Side Effects
MSM is generally well-tolerated. Reported side effects are rare and mild:
- Gastrointestinal upset (bloating, nausea, loose stools)
- Headache
- Skin rash (with topical use)
- Mild allergic reactions (uncommon)
Most side effects occur at higher doses or when MSM is started abruptly. Gradual dose escalation may minimize GI symptoms.
Drug Interactions
MSM has no well-documented major drug interactions. However:
- Anticoagulants (warfarin, apixaban): MSM may have mild blood-thinning properties; use together cautiously and monitor.
- Antiplatelet drugs (aspirin, clopidogrel): Theoretical additive effect; medical supervision recommended if combining.
- NSAIDs: No direct interaction, but combining for pain relief should be discussed with a healthcare provider.
Typical Dosing
Most studies used doses of 1–3 grams daily, divided into one or more doses. Higher doses have not been shown to be more effective and may increase side effects. Topical creams vary widely; follow package directions.
Key Takeaway: Is MSM Worth Considering?
MSM is a naturally occurring compound that is safe at recommended doses and unlikely to cause harm. However, the evidence supporting it is modest and limited to osteoarthritis and skin appearance—and even those findings are based on small, preliminary studies.
Bottom line: If you have mild knee osteoarthritis, MSM might be a reasonable trial—especially combined with stronger, evidence-based approaches like physical therapy, weight management, and anti-inflammatory lifestyle changes. The worst likely outcome is no benefit; the best is modest pain reduction.
For skin health, claims are even less established. If you try MSM for wrinkles or appearance, expect minimal changes and do not rely on it as your primary anti-aging strategy.
MSM is not a replacement for medical diagnosis, physical rehabilitation, or professional joint or skin care. Work with your healthcare provider to integrate MSM into a comprehensive plan if you choose to use it.
Related reading: Chondroitin Sulfate: What Research Shows About Joint Health | Turmeric and Curcumin for Joint Inflammation: What Research Actually Shows