Female nurse examining a patient with a stethoscope
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Dimethyl sulfoxide -- commonly called DMSO -- is a byproduct of the paper-manufacturing process that also is used as a solvent and in manufacturing products such as antifreeze. It also has purported medicinal applications, including as a cancer treatment. Additionally, the U.S. Food and Drug Administration has approved it for treating interstitial cystitis as well as in veterinary medicine. DMSO is applied to the skin or administered intravenously. Because of potential risks, you should never use DMSO without the a doctor's guidance.

Eye Effects

Early research on DMSO as a medical treatment was halted because of worries about its safety, particularly in regard to vision. If you experience vision changes, pain or burning in the eye, you should stop using DMSO immediately and contact your doctor, Drugs.com advises.

Other Side Effects

Use of DMSO can cause other side effects as well. In topical preparations, the supplement can cause skin irritation. When taken internally, some users experience headaches, drowsiness, dizziness, constipation, nausea, vomiting and diarrhea, especially when first starting a course of treatment with it, the University of Maryland Medical Center reports. In addition, DMSO can cause a garlic odor or garlic breath that can persist for several days along with bladder discomfort.

Drug Interactions

DMSO can affect how other medicines you may take act in your body, leading to potentially dangerous interactions. The effects of sedatives, blood thinners, heart medications and steroids all can be intensified when taken along with DMSO. Because of the risk of dangerous interactions, you should always talk to a doctor or pharmacist to see whether medications you take may interact with DMSO.

Industrial-Grade DMSO

Industrial-grade DMSO -- the kind used as a solvent in laboratories and in manufacturing -- should never be used medicinally, the American Cancer Society warns. These products can contain toxins and other contaminants and can be harmful in humans.

Precautions

People with certain medical conditions should never use DMSO because of how it may affect their health. Women who are pregnant or breast-feeding should never use it because of potential harm to their babies, the University of Maryland Medical Center reports. In addition, because of potential effects, your doctor may order lab tests and eye exams, Drugs.com reports. It is important to keep all appointments to avoid complications when taking the supplement.