Smoking Versus Eating

It s more efficient to smoke than eat—at least if you are trying to get high. Most of the data on smoking is derived from analysis of condensates from cigarette smoking machines, and it is unclear whether the results are equivalent to what one would get 

The main chemical chaise upon smoking seems to be decarboxylation of THC acid to THC. This is particularly important for fresh, moist samples in which the THC will not be active and will need decarboxylation. Other samples which have been heated or stored awhile normally have had the THC dccarboxyl-ated already. Smoking also converts some of the THC into the inactive CBN and produces in small amounts a number of other compounds of minor significance. Smoking docs not cause much cyclization of CBD to THC unless the marijuana is mixed with tobacco (common in most areas except the U.S.), and even then only a small amount of such cyclization may occur. 

What about water pipes A recent experiment showed that the water soluble substances absorbed in the water pipe were inactive. This is as expected, since cannabinoids are insoluble in water. However, the insoluble material that collected on the top of the water and on the walls of the pipe was very active. Relative to a condensate of the smoke which reaches the lungs, it contained 1/3 the THC, 1/4 the CBD, and slightly more CBN, Some water pipe devotees use wine in their pipes (cherry wine is my favorite) and a small percentage of cannabinoids may be 

Hashish deteriorates with time. In India it is stored only for about three years. After that, it loses its dark brown or greenish color and resinous quality, becoming brownish-grey, hard and crumbly. This loss of potency is due to oxidation the center of a chunk will remain potent longer than the outside. Raphael 

Mechoulam, the pioneer marijuana experimenter, found one chunk of hash with 2%THC on the outside, but 8% inside. Twenty years earlier, marijuana researcher Levine found that after three years a 100-pound lump of charas (hashish) had retained its potency in the center, while the crust contained 1/20 of its former potency. 

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A recent study [Clinical Pharmacol. Therap. 28, 409 (1980)] found that about 18 percent of the THC smoked appeared in the blood versus only 6 percent of that eaten. However, the situation is more complex since eating produced effects at much lower blood levels than smoking or injection. 

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