It really depends on what substance you are coming off.
For alcohol and benzos, doctors often use meds like benzodiazepines in a controlled way, plus things to help with blood pressure, sleep, and nausea.
For opioids, meds like buprenorphine or methadone can ease withdrawal and cravings, but they need to be prescribed and monitored by a doctor.
Best move is to do withdrawal under medical supervision instead of trying to guess meds on your own.