5-8 seconds is considered ideal. More time always means more THC, but beyond that it's not enough to be worth the effort.

Exhaling immediately is definitely a waste. Not all of the smoke has had a chance to hit the avioli in your lungs, so not all of the THC is out. Coughing also causes the avioli to expand, which helps the THC hit you harder - while this doesn't actually increase the amount of THC in your system, many people find that it helps boost the subjective effects of the high.
Solistus Reviewed by Solistus on . Myth or True, Holding Cannabis smoke in before exhaling? So i was into an argument with this fellow in my JavaScript class, and he says that holding cannabis smoke in before exhaling has no effect, and that really your just killing yourself by holding your breath. Hence preventing Oxygen from going to your brain. I suppose this could be true but i feel like an extra few seconds makes a difference. Even though THC is instantly absorbed as soon as you take the toke, hence the heat. I still think holding it in may get you that extra bit left? I have Rating: 5