This situation depends on the type of medication you are taking, but there are a few good rules to follow. You may also want to talk with your doctor when your medication is prescribed, in case something like this happens. In any case, if you can see the medication in your vomit, it should be safe to re-dose as it hasn’t been absorbed by your body yet. If it has been less than 30 minutes after taking the pill, yet you can’t see it, you should take the pill again as it hasn’t passed through the stomach yet. If it has been more than 90 minutes, definitely do not take the pill again as it has likely been digested already. If you are unsure, contact your doctor and provide them with as much detail as possible, like the time between when you took the medication and when you threw up. Also, tell them what medication it was, and they will weigh the risks of missing a dose or doubling a dose, as these outcomes have vastly different effects on every person.