Which System? The Mind, Body, or Spiritual system? I've heard mind altering chemicals may stay in the mental system forever. the experience may leave a " chemical tag", and one may remember the so called "High" that might never go away, since it is highly addictive, one may constantly crave that. In the spiritual system it may be perceived as a violation, or assault. 'Cause you knew it was wrong and did it anyway. So, the more one does what they know is wrong the weaker the mind and spiritual systems become making one susceptible to bigger badder wrongs, thus causing problems for everyone around you, parents, friends, etc. and even you, jail since it is illegal. It may stay in the body system only 4 or 5 days, depending on one's health. The best option therefore since the mind, body, and spiritual systems are supposed to be in sync. with each other, maybe not to use anything that tampers with either one of them in the first place.
you a food for doing it
Forever
3-5 days
It can stay there for up to 48-72 hours
3 and a half weeks
3 days
3days
7 days
About 3 months an pray their be no birth defect
It depends how long you smoked crack
Weed laced with crack presents you with two problems: weed stays around for up to a month, crack stays around for about a week.
too long buddy, your screwed if you have done crack. they will be able to tell you did that shitz for the next 50 years. Put down the pipe.