MSM (Methylsulfonylmethane)
MSM (methylsulfonylmethane, also called dimethyl sulfone) is a small organosulfur compound found in trace amounts in some foods and in the metabolism of dimethyl sulfoxide (DMSO). It is sold in the UK as a food supplement, almost always in joint-health combination products with glucosamine and / or chondroitin, or in "hair-skin-nails" formulations. There are no authorised UK food-supplement health claims for MSM. Trial evidence for joint pain is small-scale and mixed.
Camden Medicals editorial · Last reviewed 1 May 2026 · Next review November 2026
- Cross-checked against
- NHS
- NICE
- BNF
- EFSA
- FSA
Camden's editorial team independently graded each health claim below on the strength of the published evidence — see the grade beside every condition.
- Class
- Other
- Typical daily dose
- 1.5 g to 6 g per day. Lower trial doses (1.5–3 g/day) have similar effect sizes to higher doses with fewer GI complaints.
- Top use evidence
- Limited
On this page
What it is
Methylsulfonylmethane (MSM) is a small molecule with the formula (CH₃)₂SO₂ — two methyl groups bonded to a central sulfonyl group. It is found in trace amounts in cow's milk, fruits, vegetables, and some grains, and is one of the metabolic products of dimethyl sulfoxide (DMSO) — the solvent compound used historically in industrial and veterinary applications and as a topical pharmaceutical excipient.
Commercial MSM for supplements is typically synthesised from DMSO via oxidation. The two principal manufacturing standards are distillation (which produces a more chemically pure product) and crystallisation (which is cheaper but can leave higher residual solvent and DMSO levels). OptiMSM® is the most-cited research-grade preparation.
Dose-wise, supplemental MSM is typically used at 1500 mg to 6000 mg per day. Trial doses for joint-related outcomes have varied widely across this range. Higher doses do not have stronger evidence for healthy adults and increase the rate of GI complaints.
At a glance
- A small organosulfur compound (CH₃-SO₂-CH₃) found in trace amounts in some plants and in the metabolism of DMSO.
- No UK-authorised health claims; EFSA evaluation on hold for joint and connective-tissue claims.
- Most-marketed in joint complexes (with glucosamine + chondroitin) and in beauty / hair-skin-nails formulations.
- The "dietary organic sulphur" deficiency framing widely used in marketing is not supported. Sulphur-containing amino acids in normal diet (methionine, cysteine) cover the body's sulphur needs.
- Generally well-tolerated at typical supplement doses (1.5–6 g/day). Mild GI complaints and headache are the most common side effects.
What people use it for
Adults exploring joint complexes for occasional joint discomfort
No UK food-supplement health claim is authorised. Trial evidence is small-scale and mixed. UK NICE osteoarthritis guidance (NG226) does not recommend MSM. Talk to your GP about evidence-based options. [1]
Some evidenceLimitedAdults exploring beauty / hair-skin-nails formulations containing MSM
No UK food-supplement health claim for MSM specifically. Hair-skin-nails claims that appear on these products are typically carried by other ingredients (biotin, zinc, selenium, vitamin C) which DO have UK-authorised claims. The MSM in the formulation is not what the authorised claim attaches to. [3]
Popular, not provenInsufficientAdults exploring MSM for allergy / hayfever symptoms
Trial evidence is small-scale and inconsistent. UK NHS pathways for allergic rhinitis (antihistamines, intranasal steroids, allergen avoidance) apply. [4]
Popular, not provenInsufficientAdults with diagnosed arthritis or chronic joint disease
MSM is not a treatment for these conditions. UK NHS pathways apply. [1,5]
Popular, not provenInsufficient
How it works
The mechanism by which MSM exerts the effects sometimes reported in trials is not well-characterised. Proposed mechanisms include contributing sulphur to glycosaminoglycan and methionine metabolism, direct anti-inflammatory effects on synovial tissue, modulation of oxidative stress markers, and immune modulation. These are laboratory-derived hypotheses; clinical translation in humans is limited and inconsistent.
Common myths
Myth"MSM corrects "sulphur deficiency""
RealitySulphur deficiency is not a recognised clinical condition in adults eating a typical UK diet containing protein. The body''s sulphur needs are met by sulphur-containing amino acids (methionine, cysteine). The "organic sulphur deficiency" framing in MSM marketing is not supported by clinical or nutritional consensus.
Myth"MSM is a natural anti-inflammatory equivalent to ibuprofen"
RealityIt is not. Trial effect sizes for MSM in joint pain are small and inconsistent compared to NSAID effect sizes in licensed indications. UK NICE osteoarthritis guidance does not list MSM. Marketing implying NSAID-equivalence is operating outside both the evidence base and UK supplement-marketing rules.
Myth"MSM is the active ingredient that makes hair-skin-nails formulas work"
RealityAuthorised UK claims in the hair-skin-nails category attach to other ingredients in those formulations — biotin (hair, skin), zinc (hair, skin, nails), selenium (hair, nails), vitamin C (skin via collagen), and others. MSM is not where the authorised health claim sits. [3]
Common online questions
Synthesised from the questions UK shoppers most often ask online about MSM (Methylsulfonylmethane). Each answer is editorial and links to its evidence in the Sources list below.
Do I need supplemental "organic sulphur"?
The body''s sulphur needs are met by sulphur-containing amino acids (methionine, cysteine) in normal protein-containing diet. Frank sulphur deficiency is not a recognised clinical condition in adults eating a typical UK diet. The "organic sulphur deficiency" framing in MSM marketing is not supported by clinical or nutritional consensus.
Is MSM the same as DMSO?
They are related — MSM is a metabolic product of DMSO — but they are different compounds with different uses. DMSO is a solvent (industrial use), a topical excipient (some pharmaceutical preparations), and a controversial historical treatment for some conditions; oral DMSO is not a food supplement category in the UK. MSM is the more stable, odourless metabolite and is what UK food supplements deliver.
How much MSM do I need to take to see an effect?
Trial doses have ranged from 1.5 g to 6 g per day. There is no UK-authorised dose because there is no UK-authorised health claim. Higher doses do not have stronger evidence in healthy adults and increase GI complaints. If you decide to try MSM for joint discomfort despite NICE not recommending it, the lower trial doses (1.5–3 g/day) carry similar effect sizes with fewer side effects than 4–6 g.
Can I take MSM with NSAIDs or other joint medications?
Standard-dose MSM has no characterised pharmacological interaction with NSAIDs or paracetamol. Disclose all supplements to your prescribing pharmacist or GP regardless — particularly if you take prescribed medications for chronic joint disease (DMARDs, biologics).
Is MSM the same as the MSM in skincare?
Topical MSM in skincare (creams, serums) is a separate application from oral MSM supplementation. Skin-applied MSM does not have the same evidence base or authorised claim framework. Topical MSM products operate under cosmetic regulations rather than food-supplement regulations.
🔬 Camden’s evidence review
The research Camden reviewed, graded on its strength. This is our own appraisal — it sits beneath the official guidance above, never above it.
Knee osteoarthritis pain and function
LimitedEvidencelimitedA small number of RCTs of MSM (1.5–6 g/day) in knee osteoarthritis have reported modest improvements in pain and physical function scores. Trial sizes are small, durations short (12 weeks typically), placebo effects are notable, and independent replication at scale is limited. Cochrane reviews and NICE osteoarthritis guidance do not list MSM as a recommended intervention.
Allergic rhinitis / seasonal allergies
InsufficientEvidenceinsufficientA small number of trials have explored MSM for allergic rhinitis symptoms. Effect sizes are small and the evidence is insufficient to support a clinical recommendation.
Hair, skin, and nail outcomes
InsufficientEvidenceinsufficientHair-skin-nails formulations frequently include MSM but the UK-authorised claims in this category belong to other ingredients (biotin, zinc, selenium, vitamin C, vitamin A). MSM has no specific authorised UK claim for these outcomes. [3]
Exercise recovery and oxidative stress markers
LimitedEvidencelimitedSome short trials report reductions in muscle soreness and markers of oxidative stress with MSM around exercise protocols. Effect sizes are small and the literature is small. UK-authorised claims do not exist for these outcomes with MSM.
Safety
MSM is generally well-tolerated at standard supplement doses (1.5–6 g/day). Mild GI complaints and headache are the most common side effects. There is no UK-authorised health claim.
Talk to your pharmacist or GP first if you:
- You take prescribed anticoagulants — disclose all supplements.
- You take prescribed medication for chronic joint disease (DMARDs, biologics).
- You are pregnant, breastfeeding, or trying to conceive — limited safety data.
- You experience persistent GI complaints, skin reactions, or headache after starting MSM.
Common side effects: Mild GI complaints (nausea, bloating, diarrhoea) and headache are most common; usually dose-related.
Pregnancy and breastfeeding
Limited safety data; standard advice is to avoid MSM supplementation in pregnancy.
Limited safety data; avoid.
Talk to your GP, midwife, or pharmacist before starting any supplement during pregnancy or breastfeeding.
More clinical detail (for clinicians and informed readers)
Contraindications
- Pregnancy and breastfeeding (precautionary — limited data).
- Known hypersensitivity to MSM or supplement constituents.
Drug interactions
- No well-established clinically significant drug interactions; disclose use to prescribing pharmacist as standard practice.
This is not an exhaustive list. Always tell your prescriber and pharmacist about every supplement you take.
Common side effects
- Mild GI complaints — nausea, bloating, soft stools, abdominal discomfort.
- Headache.
- Insomnia (occasional reports at higher doses).
Rare side effects
- Allergic / skin reactions.
How to take it
- Typical supplemental range
- 1.5 g to 6 g per day. Lower trial doses (1.5–3 g/day) have similar effect sizes to higher doses with fewer GI complaints.
- Timing
- Daily — split with meals if higher doses cause GI complaints.
How to spot quality
Look for
- Form clearly named: methylsulfonylmethane (MSM); ideally distillation-grade rather than crystallisation-grade.
- Branded research-grade material (e.g. OptiMSM®) for combination joint products that match trial materials.
- mg per serving stated; combination products with per-component breakdown.
- GMP-certified manufacture.
- Honest framing: no "sulphur deficiency" claims.
Red flags
- Marketing as "organic sulphur" with implied dietary deficiency.
- Marketing as a "natural anti-inflammatory" equivalent to NSAIDs.
- "Joint complex" with MSM hidden in a proprietary blend.
- Hair-skin-nails formulation marketing the MSM as the active claim-carrier (the authorised claims belong to biotin / zinc / selenium / vitamin C, not MSM).
- No declaration of distillation vs crystallisation grade for purity-sensitive applications.
Commonly combined with
Other ingredients that share a biological pathway, cofactor relationship, or evidence-backed protocol with this one. Mechanisms below cite primary physiology — not folk pairing. Doses are literature ranges, not recommendations. Talk to your pharmacist or GP before changing your stack, especially if you take prescription medication.
Glucosamine
Mixed evidenceThe classic UK joint-supplement combination — glucosamine + chondroitin + MSM is the most-marketed joint-cluster trio.
Glucosamine glycosaminoglycan substrate; chondroitin sulphated GAG matrix component; MSM organic-sulphur cofactor for connective-tissue methionine cycle + modest anti-inflammatory. Mechanism complementary on joint-matrix axis.
Evidence: Cochrane reviews mixed; UK NICE NG226 OA pathway does not include either.
Doses studied: 1500 mg glucosamine sulphate + 1200 mg chondroitin + 1000-3000 mg MSM daily.
Chondroitin Sulphate
Mixed evidenceJoint-cluster classic combination — see glucosamine pairing above.
Chondroitin sulphate + MSM organic-sulphur cofactor; mechanism complementary on connective-tissue support.
Evidence: UK NICE NG226 does not include either.
Doses studied: 1200 mg chondroitin + 1000-3000 mg MSM daily.
Turmeric (Curcuma longa)
Limited evidenceJoint anti-inflammatory cluster — MSM + curcumin both feature in joint-support combinations with anti-inflammatory framing.
MSM organic-sulphur + modest cytokine modulation; curcumin NF-κB pathway inhibition. Different mechanisms; complementary on inflammation axis.
Evidence: Each has own modest trial body; combination not directly trialled.
Doses studied: 1000-3000 mg MSM + 500-1000 mg turmeric (95% curcuminoid) + black pepper 5-10 mg daily.