The blood has meanwhile delivered its oxygen to the intestinal cells and has picked up carbon dioxide. It has also absorbed THC. The blood flows into increasingly large veins which merge into the portal vein. This vein connects the intestines to the liver.
Some of the THC molecules disappear from the blood along the way. Because THC is highly fat-soluble, the molecules easily seep through the blood vessel walls and nestle into the nearby fatty tissues.
The molecules will be released from the tissues only gradually. After seven days, only 60 to 70 percent of the THC has been eliminated from the body.