Plantar fasciitis is a common source of heel discomfort, characterized by pain and stiffness resulting from inflammation of the plantar fascia, the thick band of tissue running across the bottom of the foot. Dimethyl Sulfoxide (DMSO) is an industrial solvent that has gained attention as an alternative treatment for various musculoskeletal and inflammatory conditions. This article explores the properties of DMSO and its application for managing the localized symptoms of plantar fasciitis.
Understanding DMSO’s Chemical Properties
DMSO is an organosulfur compound originally derived as a byproduct of the wood-pulp industry. It is a highly polar aprotic solvent, meaning it readily dissolves both water-soluble and fat-soluble substances. This unique chemical structure enables DMSO to pass easily through biological membranes, including the skin barrier.
This ability to penetrate tissues makes it a highly effective transdermal vehicle, capable of carrying other compounds deep beneath the skin. Beyond its solvent properties, DMSO exhibits pharmacological activities relevant to inflammation. It acts as an anti-inflammatory agent and a scavenger of hydroxyl free radicals, which are implicated in tissue damage and the inflammatory process. At lower concentrations, it may also possess analgesic properties that can help reduce pain.
Practical Application for Plantar Fasciitis
When used topically for conditions like plantar fasciitis, DMSO is often applied to the area of maximum tenderness on the heel and arch. Because of its powerful transport capabilities, thorough cleaning of the skin is necessary to remove any contaminants or lotions that DMSO could carry into the body. The product must be pharmaceutical grade, as industrial-grade DMSO may contain impurities that pose a risk when absorbed.
Users typically dilute pure DMSO with distilled water to a concentration of 50% to 70% for direct skin application, though some studies use concentrations as low as 15% when combined with other compounds. This dilution helps mitigate potential skin irritation from the concentrated solvent. The topical solution is usually applied using a cotton ball or dropper directly onto the sole of the foot, targeting the attachment point of the plantar fascia on the heel bone. Application is generally performed once or twice daily, allowing the area to air dry completely before covering the foot.
Safety Considerations and Adverse Effects
The use of topical DMSO is associated with several well-documented side effects, the most common of which is a distinctive body and breath odor. This smell is caused by the metabolic breakdown of DMSO into dimethyl sulfide, which is then excreted through the lungs and skin. The odor is pervasive and can last for several hours following application.
Local skin reactions are also frequent, including a sensation of burning, itching, or irritation at the application site. To reduce the risk of an intense reaction, users should perform a small patch test on an inconspicuous area of the skin before applying it to the foot. The ability of DMSO to enhance the penetration of other substances through the skin carries an inherent risk of transporting harmful contaminants or unintended compounds from clothing or the environment into the bloodstream.
While DMSO generally has low acute toxicity, the long-term effects of chronic use are not fully understood. If severe blistering or an allergic reaction occurs, application should be stopped immediately and medical attention sought.
Regulatory Status and Medical Guidance
The regulatory standing of DMSO is unique, as it is largely considered an unapproved alternative treatment for musculoskeletal conditions. The Food and Drug Administration (FDA) has approved DMSO for human use only for the treatment of interstitial cystitis, a chronic bladder condition. All other uses, including for plantar fasciitis, are considered off-label and lack the clinical trial data required for mainstream medical endorsement.
While some preliminary research has shown promise when DMSO is used as a penetration enhancer for other topical pain-relieving agents, it is not currently a recommended first-line treatment for plantar fasciitis. Standard medical guidance for this condition prioritizes conservative measures, such as specific stretching exercises, rest, and the use of over-the-counter arch supports or custom orthotic devices. Consulting a podiatrist or physician is strongly advised before attempting any non-traditional treatment like DMSO. This professional guidance ensures that the diagnosis is correct and that the treatment plan is integrated with established, evidence-based therapies.