DMSO Liquid is a topical solvent made from dimethyl sulfoxide, a compound derived from wood pulp lignin. The formula is 99% pure, with the active ingredient present at 90% dimethyl sulfoxide by volume, and it is organic and non-synthesized. It is applied directly to the skin of dogs and horses to help ease acute swelling associated with physical trauma. Because DMSO is absorbed quickly through the skin and can carry other substances deeper into tissue and membranes, it should be used according to label directions and under veterinary guidance. The liquid may crystallize in cooler temperatures; this does not affect its usefulness, and storing the container at or above 70 degrees Fahrenheit keeps it in liquid form. Full handling and application details are printed on the product label.