Of course, you can buy it for the requirement of a painkiller. A Hydrocodone high will last between 4-6 hours since that’s how long it takes for the drug to be cleared from the human body. In order to get high, however, you may have to take higher doses of Hydrocodone than would normally be prescribed, and this is dangerous because of the risk of overdose and addiction. Because Hydrocodone often comes combined with acetaminophen, taking too much Hydrocodone to get high can directly result in liver damage.