DMSO (Dimethyl Sulfoxide): History, Pharmacology and Safety

Dimethyl sulfoxide, usually shortened to DMSO, is a simple sulfur-containing liquid best known as an industrial and laboratory solvent. It passes through skin within minutes, and many people then notice a garlic-like taste and breath odour. Since the 1960s it has been studied as a medicine for an unusually long list of conditions. In the United States its only approved human use as a medicine is a 50% solution placed in the bladder for interstitial cystitis.

This page sets out what the published research and the regulatory record show, from the 1965 halt of US trials and the bladder label to the trials on skin, the use in freezing cells, unsupported claims and hazards. It contains no instructions for use and no sourcing information.

Table of Contents

  1. What DMSO Is: a Solvent from Wood Pulp
  2. History: the 1960s and the 1965 Halt
  3. How DMSO Acts in the Body
  4. The Only US Approval: a Bladder Solution
  5. The Bladder Evidence and Japan’s 2021 Approval
  6. On the Skin: Tendinitis, Sprains and Osteoarthritis
  7. Complex Regional Pain Syndrome
  8. Chemotherapy Leaks Under the Skin
  9. Freezing Cells: Stem Cells, Eggs and Embryos
  10. Status for Animals and in Other Countries
  11. Claims Without Trial Support
  12. Hazards: Skin, Interactions, Eyes and Allergy
  13. What Remains Unknown
  14. Key Research Papers
  15. Connections
  16. Featured Videos

1. What DMSO Is: a Solvent from Wood Pulp

DMSO has the formula C2H6OS: a sulfur atom carrying one oxygen and two methyl groups. The current US prescribing information describes it as a clear, colourless and essentially odourless liquid that mixes with water and most organic solvents, with a molecular weight of 78.13 and a melting point of 18.3 °C (label on DailyMed). It dissolves both water-soluble and fat-soluble substances, which makes it one of the most common laboratory solvents.[1][4]

It is cheap because it comes from paper making. A 1985 review describes it as “inexpensively produced as a by-product of the paper industry,”[2] and a 2016 paper explains that it is made from dimethyl sulfide, a by-product of the pulp and paper industry.[3]

The smell that people associate with DMSO does not come from DMSO itself. In the body a small part is converted to dimethyl sulfide, which leaves through the breath and skin; the label names it as the source of the odour, and a 2018 systematic review describes the smell as garlic- or oyster-like.[5] Another part is converted to dimethyl sulfone, the compound sold as the supplement methylsulfonylmethane (MSM).[6] The site’s sulfur and joint health page covers MSM.

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2. History: the 1960s and the 1965 Halt

DMSO’s medical story begins with freezing. In 1959 James Lovelock and Marcus Bishop reported in Nature that DMSO prevents freezing damage to living cells,[7] the start of its long use in cryobiology (section 9).

In 1964 Stanley W. Jacob and co-authors published the first medical reports, presenting DMSO as “a new concept in pharmacotherapy.”[8] A 2016 paper summarises that work as finding that DMSO penetrates the skin easily and carries small molecules through biological membranes, and notes the many proposed uses that followed, from arthritis to scleroderma, headaches and cancer.[3]

The enthusiasm was short-lived. In 1965 the FDA stopped all clinical trials of DMSO because it changed the refractive index of the lens in the eyes of several animal species.[3][5] A 1966 report in Science described the lens changes in dogs given DMSO by mouth.[9] A long-term study published in 1975, in dogs, pigs, rats and rabbits, found that the eye was the target organ: dogs developed central lens changes with short-sightedness after 5–10 weeks at the highest dose and were the most severely affected species; pigs and rabbits were affected at lower dose levels; rats showed only occasional minimal changes at the highest dose.[10] Human eye studies are covered in section 12.

Human research did not end. The 2018 systematic review records that DMSO was later allowed again in people because the lens effect had been shown only in animals.[5] Uncontrolled bladder studies reported relief in 75% of patients with interstitial cystitis in one 1976 series,[11] and in 1978 the bladder solution became the only FDA-approved medicine with DMSO as its active ingredient (section 4). A 1985 review observed that most DMSO trials up to then lacked the design needed for objective evaluation.[2]

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3. How DMSO Acts in the Body

Absorption and elimination. DMSO is absorbed rapidly through skin or gut.[5] The label states that after application to the skin it spreads through the tissues and body fluids; that it is oxidised to dimethyl sulfone or reduced to dimethyl sulfide; that DMSO and dimethyl sulfone leave in urine and faeces while dimethyl sulfide leaves through breath and skin; and that dimethyl sulfone can stay in the blood for more than two weeks after a single bladder treatment.

A long list of actions. Reviews describe DMSO as a hydroxyl free-radical scavenger, an agent that makes some cells mature, a cryoprotectant and a topical pain reliever.[1] A 1986 veterinary review singled out its own rapid passage across membranes and the enhanced passage of other substances it carries, free-radical scavenging, effects on blood clotting, inhibition of the enzyme cholinesterase, and release of histamine from mast cells — and noted that its effects were still incompletely understood.[4]

Pain nerves. One proposed reason for pain relief is a direct effect on nerves. Applied to exposed nerves in cats, DMSO slowed the thin C fibres that carry pain signals at 5–7% and blocked them from 9% upward.[12]

Inflammation. In human blood stimulated with bacteria or a herpes virus in the laboratory, DMSO at 0.5–2% suppressed many inflammatory signalling proteins, but at 2% it also killed a significant share of monocytes — what the authors called a narrow window of efficacy.[3]

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4. The Only US Approval: a Bladder Solution for Interstitial Cystitis

Interstitial cystitis, also called bladder pain syndrome, causes long-lasting bladder pain with frequent, urgent urination. The FDA approved a 50% DMSO solution for it on 4 April 1978, as a new molecular entity (Drugs@FDA, application 017788). Generic versions have since been approved.

The current generic label (DailyMed, revised June 2026) states the following.

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5. The Bladder Evidence and Japan’s 2021 Approval

A 2017 review noted that the best dose, how long the solution stays in the bladder, which patients respond and how many treatments to give were not agreed.[19] The site’s interstitial cystitis history page covers how the condition was recognised.

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6. On the Skin: Tendinitis, Sprains and Osteoarthritis

Rubbing DMSO onto painful joints and tendons is its best-known unapproved use, and the controlled trials disagree.

The garlic taste can tell patients which treatment they received. The 1985 review judged that DMSO on the skin seems to give rapid, temporary pain relief, with no evidence that it alters degenerative joint disease.[2] See the site’s tendinitis and osteoarthritis pages.

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7. Complex Regional Pain Syndrome: DMSO 50% Cream

Complex regional pain syndrome (CRPS) is lasting, disproportionate limb pain after an injury. Dutch researchers tested DMSO 50% cream as a free-radical scavenger.

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8. Chemotherapy Leaks Under the Skin (Extravasation)

Some chemotherapy drugs, notably the anthracyclines, can destroy tissue if they leak out of the vein during an infusion. Topical DMSO has been studied as an antidote.

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9. Freezing Cells: Stem Cells, Eggs and Embryos

DMSO’s largest medical role today is not as a drug at all. Since the 1959 report,[7] it has been the standard cryoprotectant for freezing blood-forming stem cells for transplantation; the 2018 systematic review lists cryopreservation of stem cells first among its current uses.[5] The DMSO goes into the patient with the thawed cells.

Infusion reactions. In 82 recipients of marrow frozen in 10% DMSO, many had nausea, cramps or flushing; in the largest group heart rate fell in 98% and blood pressure rose temporarily in 96%; the authors linked the toxicity to the volume of cryoprotectant and cell debris infused.[32] The 2018 review counted 204 cases of flushing in 1,439 stem cell infusions across four studies, seizures in three studies and severe encephalopathy in one patient, and found that heart and breathing reactions occurred only when DMSO entered the bloodstream.[5] A 2024 meta-analysis of seven studies found that freezing with 5% instead of 10% DMSO gave better stem cell viability after thawing and fewer adverse effects in patients, with little effect on engraftment.[33]

Eggs and embryos. The vitrification (ultra-rapid freezing) solutions used in fertility treatment commonly combine ethylene glycol and/or DMSO and/or propanediol with sugars, according to a 2023 review, which notes that vitrification stresses, including cryoprotectant toxicity, can alter epigenetic patterns.[34] A 2019 laboratory study found that even 0.1% DMSO changed the activity of more than 2,000 genes in cultured heart and liver tissue; its authors concluded that DMSO is not inert and that its use deserves reconsideration, especially for embryos and eggs.[35] See the site’s stem cells animation.

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10. Status for Animals and in Other Countries

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11. Claims Without Trial Support

A 2016 paper reported DMSO in wide use outside approved medicine — “orally, topically and even intravenously” — for pain, wound healing, inflammation, viral infections and cancer, despite a paucity of safety and efficacy data.[3] The evidence for the main claims:

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12. Hazards: Skin, Interactions, Eyes and Allergy

A carrier through the skin. Because DMSO carries what is dissolved in it across membranes, the 1986 review concluded that “combinations of DMSO with other toxic agents probably constitute its greatest toxic potential.”[4]

Purity. The approved medicine is a sterile, non-pyrogenic solution made to a pharmacopeial (USP) standard. DMSO is also widely sold as a solvent;[2] solvent product is not an approved drug and does not carry that specification, and anything else in the liquid can be carried through the skin with it.

Interactions. The label notes data that DMSO potentiates other medicines. In a randomised crossover study in eight healthy men, a dose of DMSO taken before the anti-inflammatory drug sulindac lowered blood levels of sulindac’s active form by 30% on average,[40] and nerve damage has been reported with the combination.[2] Combining DMSO with dexrazoxane is contraindicated on the basis of animal studies.[31]

Eyes. Lens changes are firmly documented in animals.[9][10] The labels differ on monkeys: the bladder label lists lens changes in monkeys, the diclofenac label none in rhesus monkeys treated for 9 to 18 months. In people, 46 patients given blinded full eye examinations during a three-month scleroderma trial showed no lenticular changes;[41] the 2018 review found no lens changes in the studies that looked.[5]

Allergy, skin and gut. Across 109 studies, gut and skin reactions were the commonest adverse effects, mostly mild, transient and dose-related; acute allergic reactions were reported in six studies, serious in two.[5] Reported systemic effects, mainly with intravenous use, include red-cell destruction, kidney failure, slow heart rate, heart block and cardiac arrest.[1]

Bleeding in the brain. Two case reports describe brain haemorrhage in people taking DMSO outside medical care: a fatal haemorrhage into brain metastases after a man with mesothelioma swallowed DMSO,[37] and two separate frontal-lobe haemorrhages in a man in his 70s using DMSO for low mood, which the authors judged DMSO the likely cause of.[42]

Decisions about DMSO treatment belong with a clinician.

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13. What Remains Unknown

Open questions include whether DMSO on the skin relieves pain beyond placebo when its taste and smell make blinding hard;[22][24] which bladder patients benefit and on what regimen;[16][19] the long-term effects of small amounts on frozen cells, eggs and embryos;[35] the risks of self-use, where dose, purity and admixtures are unmeasured and the evidence is case reports; and the mechanism itself, still described as incompletely understood.[4]

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Key Research Papers

  1. Santos NC, Figueira-Coelho J, Martins-Silva J, et al. (2003). Multidisciplinary utilization of dimethyl sulfoxide: pharmacological, cellular, and molecular aspects. Biochemical Pharmacology 65(7):1035–1041 — PubMed PMID: 12663039
  2. Swanson BN (1985). Medical use of dimethyl sulfoxide (DMSO). Reviews in Clinical & Basic Pharmacology 5(1-2):1–33 — PubMed PMID: 3916302
  3. Elisia I, Nakamura H, Lam V, et al. (2016). DMSO represses inflammatory cytokine production from human blood cells and reduces autoimmune arthritis. PLoS One 11(3):e0152538 — PubMed PMID: 27031833
  4. Brayton CF (1986). Dimethyl sulfoxide (DMSO): a review. Cornell Veterinarian 76(1):61–90 — PubMed PMID: 3510103
  5. Kollerup Madsen B, Hilscher M, Zetner D, et al. (2018). Adverse reactions of dimethyl sulfoxide in humans: a systematic review. F1000Research 7:1746 — PubMed PMID: 31489176
  6. Butawan M, Benjamin RL, Bloomer RJ (2017). Methylsulfonylmethane: applications and safety of a novel dietary supplement. Nutrients 9(3):290 — PubMed PMID: 28300758
  7. Lovelock JE, Bishop MW (1959). Prevention of freezing damage to living cells by dimethyl sulphoxide. Nature 183(4672):1394–1395 — PubMed PMID: 13657132
  8. Jacob SW, Bischel M, Herschler RJ (1964). Dimethyl sulfoxide (DMSO): a new concept in pharmacotherapy. Current Therapeutic Research, Clinical and Experimental 6:134–135 — PubMed PMID: 14135298
  9. Rubin LF, Mattis PA (1966). Dimethyl sulfoxide: lens changes in dogs during oral administration. Science 153(3731):83–84 — PubMed PMID: 5938422
  10. Noel PR, Barnett KC, Davies RE, et al. (1975). The toxicity of dimethyl sulphoxide (DMSO) for the dog, pig, rat and rabbit. Toxicology 3(2):143–169 — PubMed PMID: 1124535
  11. Stewart BH, Shirley SW (1976). Further experience with intravesical dimethyl sulfoxide in the treatment of interstitial cystitis. Journal of Urology 116(1):36–38 — PubMed PMID: 933285
  12. Evans MS, Reid KH, Sharp JB Jr (1993). Dimethylsulfoxide (DMSO) blocks conduction in peripheral nerve C fibers: a possible mechanism of analgesia. Neuroscience Letters 150(2):145–148 — PubMed PMID: 8469412
  13. Perez-Marrero R, Emerson LE, Feltis JT (1988). A controlled study of dimethyl sulfoxide in interstitial cystitis. Journal of Urology 140(1):36–39 — PubMed PMID: 3288775
  14. Dawson TE, Jamison J (2007). Intravesical treatments for painful bladder syndrome/interstitial cystitis. Cochrane Database of Systematic Reviews (4):CD006113 — PubMed PMID: 17943887
  15. Yoshimura N, Homma Y, Tomoe H, et al. (2021). Efficacy and safety of intravesical instillation of KRP-116D (50% dimethyl sulfoxide solution) for interstitial cystitis/bladder pain syndrome in Japanese patients: a multicenter, randomized, double-blind, placebo-controlled, clinical study. International Journal of Urology 28(5):545–553 — PubMed PMID: 33580603
  16. Yoshimura N, Uno T, Sasaki M, et al. (2022). The O’Leary-Sant Interstitial Cystitis Symptom Index is a clinically useful indicator of treatment outcome in patients with interstitial cystitis/bladder pain syndrome with Hunner lesions: a post hoc analysis of the Japanese phase III trial of KRP-116D, 50% dimethyl sulfoxide solution. International Journal of Urology 29(4):289–296 — PubMed PMID: 34929761
  17. Akiyama Y, Niimi A, Nomiya A, et al. (2024). Efficacy and safety of intravesical dimethyl sulfoxide treatment for patients with refractory Hunner-type interstitial cystitis: real-world data postofficial approval in Japan. International Journal of Urology 31(2):111–118 — PubMed PMID: 37817647
  18. Li HR, Shen SH, Gao XS, et al. (2025). The efficacy and safety of dimethyl sulfoxide into the bladder for the treatment of interstitial cystitis/bladder pain syndrome: a systematic review and meta-analysis. Neurourology and Urodynamics 44(5):1036–1046 — PubMed PMID: 40205912
  19. Rawls WF, Cox L, Rovner ES (2017). Dimethyl sulfoxide (DMSO) as intravesical therapy for interstitial cystitis/bladder pain syndrome: a review. Neurourology and Urodynamics 36(7):1677–1684 — PubMed PMID: 28220525
  20. Percy EC, Carson JD (1981). The use of DMSO in tennis elbow and rotator cuff tendonitis: a double-blind study. Medicine and Science in Sports and Exercise 13(4):215–219 — PubMed PMID: 6456396
  21. Kneer W, Kühnau S, Bias P, et al. (1994). Dimethylsulfoxide (DMSO) gel in treatment of acute tendopathies: a multicenter, placebo-controlled, randomized study (in German). Fortschritte der Medizin 112(10):142–146 — PubMed PMID: 8194818
  22. Brien S, Prescott P, Bashir N, et al. (2008). Systematic review of the nutritional supplements dimethyl sulfoxide (DMSO) and methylsulfonylmethane (MSM) in the treatment of osteoarthritis. Osteoarthritis and Cartilage 16(11):1277–1288 — PubMed PMID: 18417375
  23. Brien S, Prescott P, Lewith G (2011). Meta-analysis of the related nutritional supplements dimethyl sulfoxide and methylsulfonylmethane in the treatment of osteoarthritis of the knee. Evidence-Based Complementary and Alternative Medicine 2011:528403 — PubMed PMID: 19474240
  24. Simon LS, Grierson LM, Naseer Z, et al. (2009). Efficacy and safety of topical diclofenac containing dimethyl sulfoxide (DMSO) compared with those of topical placebo, DMSO vehicle and oral diclofenac for knee osteoarthritis. Pain 143(3):238–245 — PubMed PMID: 19380203
  25. Zuurmond WW, Langendijk PN, Bezemer PD, et al. (1996). Treatment of acute reflex sympathetic dystrophy with DMSO 50% in a fatty cream. Acta Anaesthesiologica Scandinavica 40(3):364–367 — PubMed PMID: 8721469
  26. Perez MRSG, Zuurmond AWW, Bezemer DP, et al. (2003). The treatment of complex regional pain syndrome type I with free radical scavengers: a randomized controlled study. Pain 102(3):297–307 — PubMed PMID: 12670672
  27. Perez RS, Zollinger PE, Dijkstra PU, et al. (2010). Evidence based guidelines for complex regional pain syndrome type 1. BMC Neurology 10:20 — PubMed PMID: 20356382
  28. Ferraro MC, Cashin AG, Wand BM, et al. (2023). Interventions for treating pain and disability in adults with complex regional pain syndrome — an overview of systematic reviews. Cochrane Database of Systematic Reviews 6:CD009416 — PubMed PMID: 37306570
  29. Olver IN, Aisner J, Hament A, et al. (1988). A prospective study of topical dimethyl sulfoxide for treating anthracycline extravasation. Journal of Clinical Oncology 6(11):1732–1735 — PubMed PMID: 3183703
  30. Bertelli G, Gozza A, Forno GB, et al. (1995). Topical dimethylsulfoxide for the prevention of soft tissue injury after extravasation of vesicant cytotoxic drugs: a prospective clinical study. Journal of Clinical Oncology 13(11):2851–2855 — PubMed PMID: 7595748
  31. [No authors listed] (2009). Dexrazoxane: new indication. Anthracycline extravasation: continue using dimethyl sulfoxide. Prescrire International 18(99):6–8 — PubMed PMID: 19382398
  32. Davis JM, Rowley SD, Braine HG, et al. (1990). Clinical toxicity of cryopreserved bone marrow graft infusion. Blood 75(3):781–786 — PubMed PMID: 2297578
  33. Bennett B, Hanotaux J, Pasala AR, et al. (2024). Impact of lower concentrations of dimethyl sulfoxide on cryopreservation of autologous hematopoietic stem cells: a systematic review and meta-analysis of controlled clinical studies. Cytotherapy 26(5):482–489 — PubMed PMID: 38416086
  34. Sciorio R, Pluchino N, Fuller BJ (2023). Review of human oocyte cryopreservation in ART programs: current challenges and opportunities. Cryobiology 113:104590 — PubMed PMID: 37804949
  35. Verheijen M, Lienhard M, Schrooders Y, et al. (2019). DMSO induces drastic changes in human cellular processes and epigenetic landscape in vitro. Scientific Reports 9(1):4641 — PubMed PMID: 30874586
  36. Collins SJ, Ruscetti FW, Gallagher RE, et al. (1978). Terminal differentiation of human promyelocytic leukemia cells induced by dimethyl sulfoxide and other polar compounds. Proceedings of the National Academy of Sciences of the USA 75(5):2458–2462 — PubMed PMID: 276884
  37. Topacoglu H, Karcioglu O, Ozsarac M, et al. (2004). Massive intracranial hemorrhage associated with the ingestion of dimethyl sulfoxide. Veterinary and Human Toxicology 46(3):138–140 — PubMed PMID: 15171490
  38. Williams HJ, Furst DE, Dahl SL, et al. (1985). Double-blind, multicenter controlled trial comparing topical dimethyl sulfoxide and normal saline for treatment of hand ulcers in patients with systemic sclerosis. Arthritis and Rheumatism 28(3):308–314 — PubMed PMID: 3884019
  39. Silvestri DL, Corey L, Holmes KK (1982). Ineffectiveness of topical idoxuridine in dimethyl sulfoxide for therapy for genital herpes. JAMA 248(8):953–959 — PubMed PMID: 7047788
  40. Swanson BN, Boppana VK, Vlasses PH, et al. (1983). Dimethyl sulfoxide inhibits bioactivation of sulindac. Journal of Laboratory and Clinical Medicine 102(1):95–101 — PubMed PMID: 6854139
  41. Shirley HH, Lundergan MK, Williams HJ, et al. (1989). Lack of ocular changes with dimethyl sulfoxide therapy of scleroderma. Pharmacotherapy 9(3):165–168 — PubMed PMID: 2755866
  42. Olds J, Yousif M, Abidakun O, et al. (2021). Case of recurrent cerebral haemorrhage in an older adult man who uses dimethylsulfoxide (DMSO) for self-management of low mood and pain. BMJ Case Reports 14(2):e240371 — PubMed PMID: 33541956

PubMed Topic Searches

  1. DMSO and interstitial cystitis — PubMed search
  2. Topical DMSO and musculoskeletal pain — PubMed search
  3. DMSO and complex regional pain syndrome — PubMed search
  4. DMSO toxicity in stem cell infusions — PubMed search

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Connections