Xylazine (or “tranq”) is a non-opioid sedative and tranquilizer only approved for use in veterinary medicine. However, over the past several years, human consumption of xylazine has begun rapidly increasing. Although initially only identified in illicit drug supplies in limited areas, xylazine has been found in 48 states as of April 2023. Xylazine is frequently, though not exclusively, used in conjunction with opioids, particularly fentanyl—due to xylazine’s ability to prolong their effects. Xylazine use presents many potential dangers to people, including an increased risk of overdose and the development of necrotizing tissue damage. This factsheet details key concerns, overdose responses, harm reduction techniques, and more.