Three years ago, Krystal Reilly elected to get a Brazilian butt lift under conscious sedation. She was told it would be a simple, painless procedure that she’d likely sleep through. In actuality, she remained wide awake and only partially numbed. The pain was “horrific,” she recalls; before the fat transfer portion of the procedure, she was handed stress balls—that’s how alert she was. Needless to say, that’s not how things should go.

Done properly by a board-certified doctor and anesthesia provider (typically an anesthesiologist and/or a certified registered nurse anesthetist) in a hospital setting or accredited surgical facility, twilight sedation, also known as conscious sedation or sedation analgesia, is a safe, pain-free anesthesia method for those who don’t want, or can’t have, general anesthesia. Here, the top eight things to know if you’re considering twilight anesthesia for your cosmetic procedure.