DMSO (dimethyl sulfoxide) is a colorless liquid with one FDA-approved medical use: treating interstitial cystitis, a chronic bladder condition. Beyond that single approved indication, it has a long list of off-label, veterinary, and experimental applications, mostly centered on its unusual ability to pass through skin and carry other substances with it. Here’s what DMSO is actually used for and what the evidence supports.
The One FDA-Approved Use: Bladder Pain
Interstitial cystitis causes persistent bladder pressure, pain, and urgency. For this condition, a 50% DMSO solution is instilled directly into the bladder through a catheter and left in place for about 15 minutes. Treatments typically happen every two weeks until symptoms improve, then taper off. This is the only human medical use the FDA has formally approved, and it’s been the sole approved indication for decades.
How DMSO Crosses the Skin
What makes DMSO unusual among liquids is how easily it penetrates biological membranes. It’s a small molecule that interacts with the fats in cell membranes in concentration-dependent ways. At low concentrations, it thins the membrane and makes it more fluid. At higher concentrations, it creates temporary pores in the membrane, dramatically increasing permeability. At very high concentrations, it can actually break membranes apart entirely.
This penetrating ability is why DMSO has attracted so much medical interest. Applied to skin, it passes through the outer barrier within minutes, and it can carry dissolved medications along with it. That property makes it valuable as a “penetration enhancer,” essentially a delivery vehicle that helps other drugs reach tissues they wouldn’t otherwise access through the skin. It works for both water-soluble and fat-soluble medications, which is uncommon for a single carrier substance.
Pain and Inflammation
The most common off-label use of DMSO is for pain relief and inflammation. When applied topically, it appears to reduce swelling, redness, heat, and pain at the application site. A systematic review looking at DMSO for wound healing and inflammation found beneficial effects in both areas: wounds healed faster, and signs of inflammation decreased. In patients with scleroderma (a condition that hardens and tightens the skin), topical DMSO increased skin flexibility and decreased pain, leading to greater range of motion.
These anti-inflammatory effects appear to be local rather than systemic, meaning DMSO reduces inflammation where you apply it rather than throughout the body. That’s part of its appeal for joint pain, sports injuries, and musculoskeletal conditions, though it hasn’t been approved for any of these uses.
Drug Delivery Through the Skin
Pharmaceutical companies use DMSO as an ingredient in topical formulations specifically because it helps active drugs penetrate the skin. Anti-inflammatory medications that would otherwise sit on the surface can be mixed with DMSO to reach deeper tissues. This is now a well-established role in pharmaceutical design, and DMSO is considered both safe and effective as a transdermal delivery agent for localized treatment.
The flip side of this property is an important safety concern. Because DMSO pulls substances through the skin so efficiently, anything on your skin when you apply it, whether that’s a medication, a lotion, or a contaminant, can get carried into your bloodstream. This is why the purity of DMSO matters enormously and why applying it without clean skin is risky.
Veterinary Uses
DMSO is widely used in veterinary medicine, particularly for horses. Veterinarians apply it topically for leg injuries and inflammation, and some administer it orally or intravenously for neurological conditions, including a parasitic brain disease called EPM. It’s also used in horses with laminitis (a painful hoof condition) for its anti-inflammatory properties and ability to reduce brain swelling. These oral and intravenous uses are off-label but legal in veterinary practice.
Laboratory and Cryopreservation
Outside of direct medical treatment, DMSO plays a critical role in laboratory science. It protects cells and tissues from ice crystal damage during freezing, making it essential for preserving stem cells, sperm, eggs, and organ tissues in biobanks and fertility clinics. This cryoprotectant function works through the same membrane-interaction mechanism: DMSO prevents the formation of ice crystals that would otherwise rupture cell membranes during the freeze-thaw process.
Side Effects to Expect
The most distinctive side effect of DMSO is a garlic-like taste, breath, and body odor that develops shortly after use. This happens because your body metabolizes DMSO into a sulfur-containing compound that you exhale and excrete through your skin. It’s harmless but unmistakable, and it can persist for hours or even a day or two. Other common side effects include skin irritation at the application site and digestive upset. The skin irritation is typically mild, appearing as redness or a burning sensation.
Industrial vs. Pharmaceutical Grade
DMSO is widely available because it has many industrial applications as a solvent and paint thinner. This creates a real hazard for people who buy industrial-grade DMSO and apply it to their skin. Industrial-grade DMSO can contain dangerous impurities, and because DMSO pulls everything it contacts through the skin and into the bloodstream, those impurities go right along with it. If you’re using DMSO topically, pharmaceutical-grade (or at minimum, lab-grade) product is essential. The price difference is small compared to the risk of introducing unknown contaminants directly into your body.
For the same reason, your skin should be completely clean and free of any lotions, creams, or other products before applying DMSO. Whatever is on your skin will be driven through it.
Where Research Is Headed
DMSO’s ability to carry other compounds through the skin continues to drive new investigations. One recent clinical study tested a solution of 30% vitamin C dissolved in 95% DMSO as a topical treatment for a type of early-stage skin cancer (squamous cell carcinoma in situ). Of 27 lesions treated twice daily for 12 weeks, 56% resolved completely, and 94% of patients avoided surgery. No one dropped out due to side effects. The study was small and uncontrolled, but it illustrates the ongoing interest in using DMSO as a vehicle to deliver cancer-fighting compounds directly through the skin.