Dimethyl sulfoxide, or DMSO, is a colorless, organic solvent derived from wood pulp that has a unique ability to penetrate the skin and other biological membranes rapidly. It functions as a powerful carrier, enhancing the absorption of substances it is mixed with. The United States Food and Drug Administration (FDA) has approved DMSO only as a prescription treatment for a specific bladder condition called interstitial cystitis. Because it is not FDA-approved for general, over-the-counter human use, anyone considering its topical application must understand the proper preparation and application amounts to avoid potential harm.
Required Grade and Dilution
The first step in using DMSO safely is ensuring the product’s quality. Users must only select pharmaceutical-grade DMSO, which boasts a purity level of 99.9% to minimize the risk of contaminants. Industrial-grade DMSO should be avoided entirely because it may contain impurities that the solvent can carry directly into the bloodstream.
Since 100% DMSO is highly concentrated and hygroscopic (meaning it rapidly draws moisture), applying it undiluted can cause immediate skin irritation, blistering, or a burning sensation. Dilution is necessary before topical application to improve tolerability. The most recommended diluent is distilled water, as tap water or filtered water may contain minerals or chemicals that DMSO could transport into the body.
Another common diluent is pure aloe vera gel, often used to create a soothing cream or gel formulation. To create a precise dilution, measure the volume of both the pure DMSO and the diluent accurately. For example, mixing seven parts of 99.9% DMSO with three parts of distilled water yields a 70% solution, which is a common concentration for topical use.
Selecting the Right Percentage Strength
The appropriate concentration of DMSO depends on the specific area of application and the individual’s skin sensitivity. Most topical applications fall within a moderate range, with 50% to 70% being the most common strength for general use. A 50% solution, achieved by mixing equal parts of pure DMSO and a diluent, is often cited as the best balance between maximizing efficacy and maintaining skin tolerability.
Higher concentrations, such as 70% to 80%, increase the compound’s ability to penetrate the skin and carry substances, but they also increase the likelihood of adverse side effects. Concentrations above 80% are not recommended for routine topical use due to the high risk of severe irritation, excessive dryness, and blistering.
For areas with thin or sensitive skin, a lower concentration is preferable. Strengths between 20% and 40% are often used to minimize the risk of local reactions like redness (erythema) or itching (pruritus).
Application Volume and Safety Protocol
When determining how much diluted DMSO to use, the principle of “start low and slow” is paramount for safety. The goal is to apply a thin, even film over the target area, not to soak the skin with the solution. For a localized area, a typical application volume is one to three milliliters (mL), or about a quarter to half a teaspoon, which is enough to lightly coat the skin.
Before applying any significant volume, a patch test is mandatory to assess individual reaction. Apply a small drop of the diluted solution to a non-sensitive area of skin, such as the forearm, and monitor it for 24 hours for any signs of irritation, hives, or excessive redness.
Since DMSO readily transports compounds through the skin, the application area must be completely clean and free of all other chemicals, lotions, or oils. Users should wash the skin thoroughly with a mild soap and water, as any residue, including perfumes or dyes, could be carried into the body. It is necessary to wear nitrile or butyl rubber gloves during preparation and application to prevent absorption through the hands.
After applying the thin film, the treated area should be allowed to air-dry completely for 10 to 20 minutes and should not be covered with clothing or bandages. The frequency of use ranges from one to two times daily. Should the skin begin to show signs of blistering or excessive pain, application must stop immediately, and a medical professional should be consulted.