DMSO: May provide support for reducing pain and swelling • May provide support for reducing joint pain and swelling • May ease muscle tension What is DMSO? DMSO 99.9% Concentrated Fragrance Free DMSO has been used for more than 100 years. It is a natural substance derived from wood pulp and is harmless when used with the proper precautions. It is sold as a solvent. DMSO is an amazing substance that has many uses throughout the world. What does DMSO do? DMSO may be helpful for relieving aches, pains, and tension.