How do you break up THC in your system?

Answer 1

THC breaks up naturally in your body, digested into metabolites like 11-OH-THC. The metabolites are the psychoactive compounds in the chemical, so a high is caused by your body digesting and processing the THC you've ingested or inhaled. You could flush it out of your system before it is digested by taking an emetic and puking it up, but you'd have to start vomiting before the high hits you, and THC reduces nausea, to make it harder for you.

If you're trying to come down off a high, there are drugs like Naloxone. Kills the high instantly, and often leaves you quite grouchy.

After THC is digested, the metabolites are absorbed into your body's fat. As the fats are burned away, it leaves your body. 20% leaves in urine, and 80% leaves in your feces. If you're trying to Dodge a urine test, you can drink a very large quantity of water, and take vitamin B2 supplements to keep the urine yellow and avoid an invalid test result. If you're trying to get it out of you quickly over time, you can lose weight (burning fats that contain THC's metabolites and flushing it down the toilet), or take antioxidants (like cranberry juice) that empty your body of toxins.

If you're trying to dodge a blood test or a hair test, no dice. The 'cleansing shampoos' are bogus, and you can't exactly replace all the blood in your body with new blood.

Mind that if you're trying to dodge a test, they won't be testing for THC exclusively. Even the multipurpose urine tests are designed to detect other chemicals from marijuana, like Cannabidiol (makes up 40% of the cannabis plant itself, cripples certain systems in the brain, inhibits growth of cancer cells). Those other chemicals tend to be much harder to expel from the body, and require different methods to do so.