The potency of cannabis can vary greatly. The marijuana smoked in the US today is much stronger than, for example, it was at least ten years ago. Its strength has increased by 13–15% (often in the case of sensims, a strong variation of marijuana without seeds), and sometimes by 30%. Similar differences and an increase in the average strength of action have been observed in hashish. The third form of cannabis, hashish oil, is a concentrated liquid extract obtained from cannabis plants through the use of solvents. The strength of this oil, which could be bought on the street for a number of years, is higher than that of cannabis leaves, from which it is extracted, or hashish. It is believed that this oil may contain up to 60% THC.

Absorption, distribution, metabolism and excretion.

The absorption of THC primarily depends on the method of use. The most rapid and effective absorption of marijuana occurs during smoking. Inhalation of marijuana leads to absorption directly through the lungs, and the manifestation of the effects of HPS begins after a few minutes. Blood plasma tests show that the highest concentration is observed after 30-60 minutes. The effects of the drug are felt for about two to four hours.

The amount of HPS accumulated during the smoking process can be determined by several factors. One of the most important constants is the power of cannabis smoked. Only half of the HPS, in principle possible in marijuana, may be in the smoke of marijuana, and its amount absorbed in the blood, respectively, will be even lower. Another factor is the amount of lag time in the lungs; the longer the smoke lingers in the lungs, the longer it takes to absorb THC. A factor that also influences perception is the number of people smoking a “school”. A large number of smokers to a large extent reduce the amount of marijuana per person.

Eaten cannabis is absorbed much more slowly and less effective. In this case, marijuana is absorbed to a greater extent by the gastrointestinal tract, and the highest content in the plasma occurs two or three hours after ingestion. An important difference from this method of smoking marijuana is that the blood in the oral cavity, which absorbs marijuana, passes through the liver before it enters the brain. The liver clears the plasma of most of the HPS, so less of it penetrates the brain. However, the effect of a drug taken as food can be tested over a long period of time, about four to six hours. It has been established that to achieve the same effect, the dose taken in this way should be three times more than when smoking.

The use of peak plasma THC levels to determine the effect of cannabis can lead to incorrect results, because psychoactive cannabinoids, as lipids, quickly dissolve in lipids and are almost completely insoluble in water. In contrast, cannabinoids are a dark, viscous, oily substance. The level of THC in plasma is greatly reduced, since the THC is distributed to the tissues of various organs, especially those that consist of fatty materials. An examination of the organs, after ingestion of cannabis, shows the concentration of THC in the brain, lungs, kidneys and liver. Thus, even when the level of THC in the blood is zero, the level of THC in other organs can vary greatly. Also, THC is able to pass through the placenta and reach the fetus.

As noted above, the THC is distributed through the blood and is located in various organs. THC over time decomposes into other, less active products. Although this occurs predominantly in the liver, metabolism can also occur in other organs. HNS metabolism products are slowly excreted through urine and skin secretions. Approximately half of the THC remains in the body for about a week and is eliminated after a few days. Some products of the HNS metabolism that can remain in the body system can be detected after 30 days using urinalysis.