Dear Doctor: What is DMSO, and can it be used to ward off cancer?

Andrew Weil, M.D. on Instagram: "DMSO aslo known as Dimethyl Sulfoxide, is a topical treatment that can offer effective, short-term relief for acute pain conditions like bursitis or trigger finger. While I do think DMSO is great option when used briefly and selectively, as it rapidly penetrates the skin to ease discomfort, I do not recommend it for long term or chronic use."