At the time of ingestion, Methocarbamol can last in the urine of an individual for a total of four hours. This can vary from person to person depending on their health or age. For example, the drug may stay in your system longer if you are a person who is 55 years of age or older. About only two percent of the Methocarbamol is absorbed and will continue to last in the blood for the next 24 hours after ingestion.