How Long Does THC Stay in Your System?

​THC stands for Tetrahydrocannabinol. THC is cannabis’s central psychoactive element. Employers in the United Kingdom have in recent years favoured carrying out random drug tests on their employees. Drug tests are particularly common in heavy industry, the Armed Forces and public organisation. An entire multi-billion pound drug testing industry has popped up in the last decade catering to this need.

If you are a regular or even infrequent cannabis user then you may worder how long THC remains in your system. This post attempts to provide an answer to your question.

So…just how long does THC stay in the blood?

The answer is… it depends!

If you are subject to a random drug test then know your cannabis use could risk your job! THC is stored in the body’s fat cells so expect detectable levels of the drug to remain in your system for longer periods than say cocaine or ecstasy. The length of time THC remains in the body depends on a number of factors. The key determining factor is the frequency of your cannabis use. If you use cannabis infrequently the drug does not remain in fat cells for more than roughly 10 days. Frequent cannabis use means THC remains in fat cells for a period up to 90 days. That’s three months!

THC is known for its ‘hydrophobic’ properties. This means THC is not easily metabolised by water. THC is both fat-soluble and non-polar. THC survives in the body un-metabolised. Eventually THC is absorbed by fat cells located throughout the body. Organs with high blood circulation such as the heart, liver, brain and lungs absorb the majority of THC from the blood. Fat cells in these organs then ooze THC into the body’s blood stream. THC is metabolised in the liver forming THC-COOH. THC-COOH then exits the body through urine. Therefore urine tests reveal THC-COOH even months after cannabis was consumed. THC-COOH is also detectable via hair-follicle testing.

Why fat cells matter

Detection of THC in fat cells also depends on the method of drug testing employed. A urine sample reveals THC consumed up to four weeks ago. However a blood test reveals THC consumed in the last six months.

Since THC resides in the body’s fat cells, THC users with little body fat can expect a reduction in the amount of time it takes the body to purge remnant THC. Overweight cannabis users harbour THC for much longer than their skinnier counterparts. Likewise THC users with a ‘fast metabolism’ should also expect a quicker THC purge cycle.

For those who suffer from cannabis addiction

If you suffer from an addiction to cannabis why not consider a comprehensive 28 day cannabis rehabilitation programme at our rehabilitation centre in London.