Do your roaches have more THC ?

Some confusion exists over what happens to THC in cannabis smoked in cigarettes.
That is, what's left behind in the so called "roaches".

A long time ago i asked myself this question with the initial hypothesis that all of
the THC would be gone from the roach. I presumed this would occur since the THC would be heated from the upper part of the burning cigarette, making it volatile and sending it from the un-burnt cannabis further up the cigarette.

To test this i first ran a sample of cannabis on the HPLC by the usual methodology
and determined the THC concentration. Then a sample from the same batch of cannabis
was rolled and smoked in a cigarette, saving the last, roughly 1 cm (0.3 gm). This "roach" was
then prepped and run on the HPLC by, once again the same methodology, and the two samples compared.

Surprisingly, the "roach" sample was 5-10 mg/gram higher than the original sample.
How could this be?
Well if you think of it, why not? The resin will accumulate at the butt of the cigarette,
and it would have to reach temperatures near 200 degrees C (almost 400 degrees F) to boil off. As one pulls on the cigarette the resin oils are physically pulled back and accumulate in the cooler, butt, slightly increasing the amount of THC.

The THC, in the "roach", is for the most part activated, or decarboxylated, such that it can bind the THC receptor.
So one suggestion, would be to eat your roaches…

Dr. Hornby & research team
July 22, 2009