A new THC rapid test can detect recent cannabis use in just a few minutes, compared to the up to five days required for urine rapid tests. The policy of many countries, including Germany, has become increasingly open to the legalization of cannabis in recent years. According to the United Nations World Drug Report 2021, around 200 million people worldwide regularly use cannabis. However, like alcohol, cannabis is a psychoactive substance that impairs human senses, making users a potential danger on the road. Therefore, Germany has set a limit that must not be exceeded by road users, which is 1.0 nanogram of tetrahydrocannabinol (THC) per milliliter of blood serum. However, this limit is controversial and is still being debated in the German Bundestag.
To determine whether the THC limit has been exceeded, urine, blood, or sweat samples are usually used. However, the results of urine rapid tests can take up to five days to come out. Until now, there have been no tests that can quantitatively, easily, and quickly detect the THC content in the body. However, scientists at the Center for Systems Biology at the Massachusetts General Hospital Research Institute have developed a new THC rapid test that can detect recent cannabis use in just five minutes using saliva. The test, called the EPOCH system (express probe for on-site cannabis inhalation), is based on an optical sensor that can detect THC in saliva samples.
In an experiment with 86 subjects, half of whom were cannabis users and the other half had never used the drug, the scientists tested the practicality of their development. In conjunction with a smartphone, the EPOCH system was able to detect THC in all subjects who had eaten food or inhaled a gel containing cannabis just a few minutes before the test. The median concentration in saliva was 478 nanograms/milliliter for inhalers, which quickly dropped after a half-life of 1.4 hours, and the limit of one nanogram/milliliter was already below after six hours. The test system was able to detect concentrations of up to 0.17 nanograms/milliliter, which were reached 12 hours after cannabis use. This new THC rapid test could be a game-changer in detecting recent cannabis use and ensuring road safety.
