Drug testing is most commonly done by urine analysis, but sometimes they test hair follicles, or saliva from a mouth swab. There are two basic kinds of urine drug analysis tests, EMIT dipstick & GC/MS lab tests. The EMIT test is often used first, and if that indicates possible drug use, then they forward your sample to to the lab for the more thorough test.
When it comes to urine drug testing, there are no real magic pills or potions to make you pass, but there are plenty of scams and misinformation. If you ignore all the "guarantees", common sense should tell you that any method of detox or dilution is a gamble, and simply won't work for everyone. Some methods may even seem to work for a majority of those making such claims, but if you don't want to take your chances or risk any failures, and you would rather be 100% sure to pass... then aside from complete abstinence from THC for a couple of months, substitution of synthetic urine is clearly the best way to go for unobserved tests like for pre-employment. What's your test for? Probation & pre-employment tests are completely different in terms of privacy and consequences. If it's observed like for probation, don't risk trying to sub or anything, just follow all the steps for the dilution method below, especially including getting some home THC tests, and checking your 1st void of the day, practicing the method, and retesting yourself after to make sure it works, then repeat on test day. or if it's just unobserved, like for pre-employment, then you can use the dilution method as a backup plan, and go with substitution as your primary method.
How soon you can get clean or succeed with dilution depends mostly on how often you've been smoking during the past month. 30 days is probably about right for daily smokers to get clean, but it does vary widely based mostly on a person's metabolism. Some young skinny guys who can eat as much as they want without gaining a pound could be clean in 2-3 weeks, while others with slow metabolisms can take a couple of months, and fat older guys could take even longer. Also some people who exercise regularly can cause themselves to test dirty even longer, until they stop burning fat, and get their body into a fat-storing mode.
If it's possible, a little abstinance from the herb can make a big difference. If you smoke or consume cannabis on a daily basis, then if you can stop for at least 4 or 5 days, your THC levels will begin to drop dramatically, and then much more so, if you can go for 7 or 8 days. But if you only smoke 1 or 2 days per week, then you could possibly get mostly clean naturally within 2 or 3 days, so following that tactic can also be very beneficial. Lowering your levels through abstinance, can greatly help you succeed with the dilution method. Also note that the amount you consume during each given day, isn't nearly as relevant as the number of consecutive days which you have consumed or not. Your body refreshes itself while you're asleep, so if you've consumed any cannabis that day, it can only strive to restore your level to nearly that of the previous day... the success of which would vary somewhat depending on the amount consumed, but each day that you do not consume cannabis at all, your sleep period can make real progress in lowering your level, instead of just treading water. Also note that simply getting more sleep, or a solid 8 hours, each night can be highly beneficial. There is a neat little program call the THC Calculator, which I'd recommend downloading and trying out, that illustrates the effects of taking some days off from consuming cannabis. It's not really very accurate, but at least it's in the ballpark, except that it seems to take some people even longer than the maximum time indicated to get clean. It illustrates nicely how smoking daily or just a few times a week can really affect things, and it can account pretty well for when someone smokes and abstains and smokes again at odd intervals. Of course it can't take the place of a real at-home thc test, but at least it's fun to play with, while teaching the value of periods of abstinance, and can help give all those who are wondering where they stand a pretty good idea to begin with.
http://www.drugs-plaza.com/downloads/calc_thc.exe
If you have less than two weeks until your test, it can be counter-productive to exercise or try to burn fat by any means, But if you do have 2 weeks or more to work with, increasing your metabolism and burning off some fat is the best way to speed up the process of getting clean and to help insure that you won't become one of the unlucky exceptions. That can be done by various means, but it's best accomplished through exercise and a diet of fat-burning foods... and since it takes a few days for such as program to really start working, then you want to work it for a good week or two to get some results, and then you must spend a few more days afterward getting your body into a fat-storing mode before your test... so you'll need to get started asap as such a plan requires at least 2-3 weeks to complete. Too many people make the mistake of trying to burn fat within a few days before their tests, and just increase their chances of failure.
The benefits of fat-burning foods, such as apples, berries, fresh citrus fruits, soybeans and garlic oil are detailed in the quote at the end of this post. Any type of roughage type food is good up until a few days before your test, while eating fatty foods and laying around is probably the worst thing for you at this point. Instead try to eat fiber and low fat foods; good choices are eggs, peanuts, bran, low fat turkey, chicken, salads, fruits and vegetables, cranberry and other fruit juices, wheat's, liver, soy, proteins. Things to avoid include greasy foods, high carbohydrate type foods, white breads, high sugar foods, candy, chocolate, and the like. Sure this seems more like a weight loss diet, but the goal here is to consume foods that will force your body to break down fat reserves and turn them over into new cells, thereby removing the THC metabolites that collect in the lipid tissue. Fiber, for instance, causes more fat cells to be excreted through the feces; cranberry juice helps to excrete more toxins into the urine stream. There are many ways to clean out quickly, but these are tried and true methods. Combining this with a good exercise regimen, you are arming yourself with two very important factors to a faster detox time. Working out with weights is important as building muscle mass will replace stored fat and increase your metabolism. 20 to 30 mins of cardio exercise, 5 days a week is also quite important, such as brisk walking, swimming, exercise bike, treadmill, or elliptical trainers are all good. Also getting plenty of sleep, like 8 hours each night, is helpful.
Home THC tests are very useful and important, and quite dependable... even the ones that only cost $1-2 on ebay. You might want to try this link and then sort them by lowest price first:
http://www.ebay.com/sch/i.html?_nkw=thc drug test&_armrs=1&_from=R40&_ipg=
I'd suggest getting at least a 5-pack, for the same cost as a single test from a retail store. Then you can use a couple of them on your first voids of the day during the last week or so, and still have a few left to use for the dilution method if you need to... one the morning before your test, and if that's positive, then do another after practicing dilution, and save the last one for the next day, again after dilution, right before the real test. Unless you're coming up clean with the first or second home test, you'll want to prepare to follow the dilution method detailed below carefully and do a practice run to make sure it works. You'll probably want to stop by GNC for the vitamin B2 (50mg)and some creatine which needs to be taken for the last few days before a test so they can't tell if it's diluted. Also pick up some Tums or Rolaids, Gatorade and regular Bayer 325mg aspirin, which has been lab proven to help cause false negatives on the EMIT prescreen tests. Again, be sure to stop the exercising and switch your diet to fatty foods for the last few days to get your body into a fat-storing mode in time for your test. Fast-food like McD's or KFC is good for that, or pretend it's your birthday and have some cake and ice cream... and red meat like a nice thick rare steak or prime rib can help supplement your creatine, as can some flavors of Sobe's which come loaded with it too, which is a good option for vegetarians. For breakfast on the morning of the test, a cheese omelet can provide a riboflavin (B2) boost.