When I first started smoking in college, everyone knew to hold the bong hit as long as possible so that you got the best high. Fast forward ten years later, and folks are telling me that it's an urban myth and it doesn't do anything to the quality of your high. What's the deal when it comes to "holding your high”?
— Help Me Get Higher!
Thanks for your question! While you might have learned a lot of great information in college, it's good to circle back about things like this that have to do with cannabis. Especially in this case, as what you previously learned may have been just a bunch of smoke.
I understand why folks feel that the longer they hold in a bong or bowl hit, the stronger the high will be. After all, you do feel a little extra light headed right after… but, don't forget that you just held your breath for a significant amount of time, and that could contribute to the immediate woozy feeling! When you deprive your brain of oxygen and infuse it with carbon dioxide (i.e. holding in all that delicious smoke), you can easily get a head rush, as well as an increase in heart rate (as your heart races to try and deliver more oxygen to you), causing you to feel super high. That initial head rush will dissipate pretty quickly, as soon as you let oxygen back into your system.
Science tells us that while you might feel like you've strengthened your high by holding the smoke in your lungs, you're actually not absorbing that much more THC. An older study from 1989 asked participants to inhale cannabis smoke and then hold it for three different intervals from zero to 20 seconds. Researchers were unable to detect a measurable difference between folks who held in the smoke for awhile versus those that did not. That means you can hold in a bong hit for two seconds or 20, and you'll still experience the same sort of high.
Some studies suggest that THC (aka the psychoactive compound in cannabis that gets us high) is absorbed almost immediately — within 5-10 seconds, depending on the person. So to hold smoke in your lungs for a longer period of time is most likely doing more (lung) damage than anything else. What is more impactful when it comes to how much THC you absorb is what method you're using to inhale cannabis, rather than how long you hold it in for. For example, a high from a vape pen will differ than the high off a bong. It will also differ if you're smoking flower versus oil or wax, obviously.
While you could just go ahead and keep holding your high for as long as you physically can just on the off chance that science is wrong, you probably shouldn't. Not only will it most likely not increase your high, but holding irritants like smoke and tar inside your lungs for too long is not good for the sensitive tissue. Why stress your lungs out even more than they need to be?