For years the warning around cannabis and driving has been simple: don’t drive high. That part isn’t controversial. But what about the morning after?
A new study looking at frequent cannabis users suggests that the feared “weed hangover” may not be much of an issue when it comes to driving performance. Researchers found no significant impairment 12–15 hours after cannabis use when participants were put through driving simulations and cognitive tests.
In the study, regular users consumed cannabis in the evening and were tested the following day—roughly the timeframe many people would normally be commuting to work or running errands. When researchers measured things like lane control, reaction time, and overall driving ability, participants performed about the same as people who hadn’t used cannabis.
The findings add to a growing pile of research showing that cannabis impairment tends to be short-lived, with the strongest effects occurring within the first few hours after consumption. By the next morning, those effects appear to fade for most regular users.
That doesn’t mean it’s suddenly a good idea to light up and immediately grab the car keys. Driving while actively high is still dangerous, and factors like dosage, tolerance, and how cannabis is consumed can change how long impairment lasts.
But the study does challenge one lingering assumption—that using cannabis the night before automatically means you’re still impaired the next day.
For many regular users, it seems the joint from last night stays exactly where it belongs: in last night.
Dabbin-Dad Newsroom
