DMSO Roll-On is a high-purity liquid solvent derived from wood pulp lignin, processed to 90% dimethyl sulfoxide by volume. The formula is housed in a bottle fitted with a roller-ball applicator, which spreads the liquid across the skin without requiring direct hand contact. It is intended for topical use on horses and dogs, where handlers apply it to areas associated with joint stiffness, inflammation, or swelling. Because dimethyl sulfoxide penetrates the skin barrier quickly, the product can also act as a carrier that helps move other topically applied substances into deeper tissue, so use should follow label directions and any guidance from a veterinarian. The liquid is pyrogen-free and acetone-free, requires no assembly, and can crystallize in cold temperatures, returning to normal function once warmed and thawed. Storing the bottle in a cool, dark location away from direct sunlight helps maintain its condition between uses.