The answer is: "it depends". The main psychoactive substance in magic mushrooms is psilocybin (psilocin). In most countries psilocybin and psilocin are illegal. However, in quite a lot of countries this does not imply that the psilocybe mushrooms are illegal as well. Unprocessed, fresh magic mushrooms are legal in many countries. See also the notes under 'Drying, storing and the LAW' in the conserving section.
From July 2005 frah magic mushrooms are banned in he UK. See thelink at the ight side.
Until November 4, 2002 fresh and dry magic mushrooms were legal in the Netherlands. From this date, however, the supreme court decided that dry magic mushrooms are illegal. Why? Because the are considered a psilocybin containing preparation (somethin processed by a human being). Happily, fresh magic mushrooms are still legal to possess and sell.
After a week, no URINE or BLOOD based drug test will diagnose psilocybin. So, make sure that within a week after taking you are not tested for drugs. Psilocybin is (unlike cannabis/marijuana) not soluble in fat. So it will NOT stay in your body for a long time.
Is it possible to trace the use of magic mushrooms in your hair? Until now I did not found literature about this issue. However, I THINK that even in hair-analyzing-tests psilocybin will not show up (unlike for example cocaine). The active dose of psilocybin is 5 to 20 miligrams. Virtually nobody uses magic mushrooms on a daily basis (unlike alcohol, cocaine, heroin) because it is not an addictive drug and the effects will go away after taking it every day. So, most people only get very little amounts of psilocybin in their system. Because of this the chances that it shows up in a 'hair-test' are very, very slim.
My son has just graduated from college, and is planing to become a police officer. He came home one night high as a kite, and the next morning we had a descusion and he told me he had taken 4 grams of magic mushrooms. My question is how long do they stay in your system for? and if the police do a drug test on him will it show up that he has taken them?
The experience lasts about 4 - 6 hours. Within 24 hours completely baseline. Within 5 days no traces. After a week impossible to detect. Most drug test do not test for psilocybin. Dont worry 2 much! Hope this helps, dick