What is the recommended percentage of DMSO (Dimethyl Sulfoxide) for topical use?

Recommended Percentage of DMSO for Topical Use

For topical applications, DMSO should be used at a concentration of 50% to balance efficacy and minimize adverse effects. 1, 2

Evidence-Based Recommendations

The optimal concentration of DMSO depends on the specific application and treatment goal:

• FDA-approved use: RIMSO-50® is a sterile solution containing 50% dimethyl sulfoxide (DMSO) and 50% water, approved for the symptomatic relief of interstitial cystitis 1

• Pain management: The European Society for Medical Oncology recommends starting with lower concentrations (around 50%) to minimize skin irritation while maintaining therapeutic effects 2

• Concentration-dependent effects:

  • Concentrations higher than 70% (90-100%) can aggravate inflammatory responses and cause significant skin irritation 3
  • 50-70% concentrations show neutral effects in some inflammatory models 3
  • 30% concentration demonstrates anti-inflammatory properties with minimal irritation 3

Safety Considerations

When using topical DMSO, be aware of these important safety factors:

• Adverse reactions are dose-related and generally mild to moderate:

  • Local erythema, skin rash, and pruritus (especially at higher concentrations) 2
  • Garlic-like taste and odor on breath and skin (may persist up to 72 hours) 1
  • Potential discomfort upon initial application 1

• Administration guidelines:

  • For experimental agents in animal studies, DMSO should not exceed 5 ml/kg or 10% of injected volume 4
  • For topical use in humans, concentrations around 50% balance efficacy and tolerability 2, 1

• Drug interactions: The safety of DMSO in combination with other drugs has not been fully established, with reported neurotoxic interactions with sulindac 5

Clinical Applications

DMSO has several established and investigational uses:

• Penetration enhancer: DMSO enhances diffusion of other medications through the skin 2, 5

• Pain management: Provides temporary relief of pain in patients with arthritis and connective tissue injuries 5

• Extravasation treatment: 50% DMSO formulations are used to prevent local complications from extravasation of cytostatic drugs 6

• Dermatological conditions: Shows promise in treating macular amyloidosis, scleroderma, and other skin conditions 7, 8

Formulation Considerations

The vehicle in which DMSO is delivered affects both efficacy and tolerability:

• Semisolid preparations (hydrogels, o/w emulsions) at 50% DMSO concentration can provide controlled release and reduce irritation compared to pure solutions 6

• Solution forms are more commonly used but may cause greater irritation due to rapid absorption 5

Common Pitfalls to Avoid

• Using excessively high concentrations (>70%) can cause significant irritation and may worsen inflammation 3

• Applying to broken skin increases absorption and potential for systemic effects 2

• Ignoring potential drug interactions when using DMSO as a vehicle for other medications 5

• Failing to warn patients about the characteristic garlic-like odor, which is a common reason for treatment discontinuation 1