The onset of action will depend on the route of administration, as will the metabolism and duration of effects. THC is very lipid soluble, stored in the fat reservoirs and slowly released into the bloodstream. It has been reportedly detected in the bloodstream at least 28 days after use and has implications for individuals undergoing drug testing procedures. The effects of cannabis vary between individuals and depend on the dose, the route of administration and also the conditions under which observations are made. The psychoactive effects are split into desirable and undesirable, but it is the physical effects that have been exploited when finding new ideas for its use.
Hallucinations are rare and are only seen at high doses.
There have been no reports of acute cannabis poisoning. The drug has an effect on psychomotor performance and may interfere with skilled tasks. However, reports state that drivers who have taken cannabis tend to drive more slowly and take fewer risks than those on alcohol. There is not, as yet, any clear evidence of the effect of chronic use on the immune system. Its use in pregnancy and women trying to conceive should be dis-couraged as it may interfere with foetal development.