why does vapor take longer to absorb?

What evidence proves vapor takes longer to absorb? Many people seem to mention it but i've never seen any studies (formal or not) that prove it.. if so why does it take longer? Thanks

In my experience, it doesn't take any longer than smoke does, vapor seems to be maybe even faster depending on how large of dose you absorb at once. If you take a dab of concentrate like oil you will feel it immediately. I think the perceived duration of absorption is due to the fact that the process of vaporization takes longer than it does to combust a bowl of flowers. In a convection or conduction vape, it might take almost double the time to finish a bowl than it does to combust the same amount. These are my thoughts...

When i buy a bong ill have to test this out. Im thinking of filling it with oil and blowing into it. Once with vapor held in for 10 seconds, once with 5 and one held in for 2 seconds. Paying attention to variables like quantity of herb used and color of vaped poo. Then perform something like thin layer chromatography to test concentration of cannabinoids.. anyone have a better method suggestion? I can't imagine tlc being the best method...

I've always had the impression it was because THC actually takes about 15-20 minutes to fully kick in, and that the initial rush experienced when smoking was mostly due to combustion byproducts.
I don't have any sources or anything so it might not be true.

I must say I can confirm the feeling of vaping having a delayed effect opposed to combustion. And I had the same remark from friends as well.

(Seconds after vaping; "man this is weak". 10-15min later; "man, I'm wasted")

I have no theory of why this is the case tho.

that got one of my friends too, he visited and we vaporbonged, he said he barely noticed it, like 1 hit from a joint. later when I was walking him to the bus stop he said he began feeling high, and the next day he reported having been very high

There is certainly a difference in high as well. I suppose there's "active stuff" that is only released with combustion and not with vaping?

Not quite, you're right, combustion creates byproducts which can contribute to the perceived difference in the high. When you vape, you don't get any of those byproducts. Smokers who vape for the first time sometimes feel like the high is lacking and incomplete, but what they are really feeling is the lack of those combustion byproducts.

So you're saying that there is "active stuff" released with combustion that is not released when vaping?

yes yes yes! haha my bad, I misinterpreted your post

Toxic byproducts unrelated to the cannabinoid family. What you're getting is organic carbon molecules binding to whatever the hell they can to.. which is nearly everthing if i remember o chem properly.

Well it's not that it's not released, it's that the lighter destroys a lot of the terpenoids instantly, so you get more with a vape.

And the chemical reaction only takes about 3/100th's of a second if im not mistaken,but the reason the effects seem to take longer is because the reaction is less exothermic then when combusting. I've noticed it taking longer to kick in then when combusting pretty much every time. This is also why at least for me, the vape high last longer then when combusting.

1^ and 2^^ Seem to have answered the OP, at least to me.

Your thoughts about temperature effecting abosrbion rate is interesting.. to take things one step further smoke is probably much denser than vapor increasing the concentration gradient and speading absorption

I agree. I think being that vapor is lighter it's also easier to get the stagnant vapor in the middle of your lungs to touch the walls and be absorbed. I've noticed even when using the EQ and ramping up the temperature as time goes one, gets me higher quicker then through an IO, but not necessarily higher over all, even though I can bigger, thicker hits from the IO.

I noticed that with my first trial of a true vape...rather than the vape I had at that moment in time, which was rubbish...Vaporeyes, crap product.

A couple of years back me and the Mrs were on a kid free weekend in Amsterdam, while there we picked up a flyer for a coffee shop that had vapes on the tables...we got to give that a visit, I thought...even although I was still combusting at that time.
So we visited and I tried...at first, once I learned how to use the vape properly...courtesy of the guy behind the counter, lol...I was blowing clouds and coughing like god knows what...typical combustor or now ex-combustor, lol...I was thinking, yeah not bad but a spliff is still better...then we stepped outside and a few moments past as we were walking and I thought..."Wow", this is some going...way better hit than a spliff for the amount used...so I definately think that vaping does give a slightly delayed reaction but what a stone for so little product used....better than setting it on fire, for sure.

This! One of things i love about vaporizing that I can vape, put my stuff away, get to things I want to do and then I start feeling the high kicking in and enjoying it instead of having it hitting me right there on the spot.

Same here...if you ask me, until you have done 2-3 bowls right at the back of one another, it's a more uplifting stone...but 2-3 bowls immediately and you got no hope...turn on day-time tv and vegitate...lol.

My theory is that it's the rate that the active ingredients hit your bloodstream - in what ratio and over what length of time.

With combustion you get everything at once, in rapid succession, and decarboxylation is very rapid. With vaping the acids decarboxylate much more gradually, over many minutes, so instead of getting all of the active ingredients together you're getting the most volatile ones first (flavinoids, terpenoids), then progressively more THC, then progressively more CBD, each over their own time window depending on the rate of decarboxylation and boiling point. If you Google "Ethan Russo entourage effect" you can read his theories on how those flavinoids and terpenoids can change the effect of the cannabinoids, and vaping makes this more pronounced in my opinion.