About Herbs

Bottom Line: DMSO may help to relieve pain but more studies are needed to confirm its safety and efficacy. There is no evidence that DMSO can treat cancer in humans.

DMSO is a widely used chemical solvent. It is rapidly absorbed when applied to the skin and has been shown to reduce pain and inflammation. However, there are concerns of adverse effects include damage to the nerves. DMSO is used as a prescription drug to treat inflammation and pain of the bladder and as an antidote for chemotherapy drugs that leak and are trapped inside the body. DMSO has not been shown to be an effective treatment for cancer in humans.

Because of the side effects associated with DMSO administration such as a strong garlic taste, few clinical trials have been performed.

Dimethylsulfoxide (DMSO) is a widely used chemical solvent because of its high polarity. It is used in the laboratories as a cryopreservative. DMSO is readily absorbed by the skin and has been studied as a vehicle for topical drugs. DMSO is thought to have analgesic and anti-inflammatory properties and has been used topically to relieve pain and to treat arthritis. Small scale studies conducted in the early 1980s suggested that DMSO may help to relieve peripheral neuropathy ⁽¹⁾ and post-thoracotomy pain ⁽²⁾. A systematic review of DMSO for osteoarthritis reported a lack of definitive evidence to support this use ⁽³⁾ and a recent meta analysis and systematic review of limited data concluded that DMSO offers no benefits over placebo ^{(4) (5)}.
DMSO has been used to prevent or treat extravasations of chemotherapeutic agents ^{(6) (7)}. It may also slow down the progression of cancer cells; however, data are inconsistent ^{(2) (8)}.
DMSO has been shown to cause neural damage in animals ⁽⁹⁾. Topical application of DMSO leads to a strong garlic taste in the mouth ⁽¹⁰⁾. Intravesical DMSO is an approved prescription drug for the treatment of interstitial cystitis. DMSO is not approved for use in other forms due to lack of studies analyzing its efficacy and potential toxicities.

DMSO is diluted on exposure to air. Upon topical application, it rapidly penetrates the skin; however, unlike most penetrating solvents, it is not associated with irreversible membrane damage. DMSO can enhance the skin penetration of other drugs. Analgesic and anti-inflammatory effects may benefit patients with rheumatoid arthritis ⁽²⁾. In addition, DMSO traps free radical hydroxide; its antioxidant properties are thought to be responsible for the prevention of chemotherapy extravasations ⁽⁷⁾. A strong garlic taste in the mouth following DMSO administration comes from the exhaled dimethylsulfide (DMS) metabolite ⁽¹¹⁾.

Absorption
After topical application, DMSO can be located in the blood within five minutes, all organs within 20 minutes and bones within an hour ⁽²⁾.

Metabolism/Excretion
Elimination half-time is about four days, however cutaneous application prolongs elimination by about one third. Excretion of DMSO is primarily via urine ⁽²⁾.

DMSO is an approved prescription drug for the treatment of interstitial cystitis intravesically only. It is not approved for over-the-counter use in any form due to inadequate evidences of efficacy and potential toxicities. The industrial form of DMSO may be contaminated with other chemicals.

Reported (Topical): Garlic taste in mouth, dry skin, erythema and pruritis ⁽²⁾ urine discoloration, halitosis, agitation, hypotension, sedation dizziness ⁽¹³⁾. Changes in eye lens have been reported in animals following administration of DMSO ⁽¹²⁾.

DMSO can decrease the therapeutic effect of sulindac and may cause peripheral neuropathy.

DMSO may also decrease the effect of dexrazoxane.

Most of the clinical studies done on DMSO were published in the 1980s and early 1990s. There are only limited reliable data from clinical trials to verify the purported uses of DMSO.