By: Elizabeth Hartney, BSc, MSc, MA, PhD
THC stands for delta-9-tetrahydrocannabinol or Δ-9-tetrahydrocannabinol (Δ-9-THC). It is a cannabinoid molecule in marijuana (cannabis) that’s long been recognized as the main psychoactive ingredient—that is, the substance that causes people who use marijuana to feel high.
THC works by attaching to the body’s cannabinoid receptors, which are found throughout the brain and nervous system. THC can be detected in the body much longer than most other drug compounds (up to 20 hours after ingestion), although the psychoactive effects only last for a few hours.
THC is also stored in body fat and organs for three to four weeks. Hair follicle testing may identify THC after even longer periods of time, around 90 days. Urine testing is often used but has been found to be an unreliable method of detection.
THC is often smoked as marijuana (dried leaves of the Cannabis plant), but there are actually a number of different ways that THC can be used. It can be consumed by:
With the popularity of CBD, there has been a major market shift toward producing a seemingly endless variety of CBD products. Some of these products may contain traces of THC (around 0.3% to 0.9%), depending on how they’re formulated.
This small concentration is highly unlikely to result in a feeling of high, and some experts argue that the effectiveness of CBD is potentiated by small amounts of THC. However, if you’re looking for a CBD product without any THC, be sure to seek out a source that uses third-party testing to certify the purity of the product.
THC is used recreationally, but it also has a number of medicinal uses as well. Marijuana has been used for medicinal purposes for thousands of years, but research on its use to alleviate and treat illness is still relatively recent.
Some of the ailments that THC may help include:
The FDA has also approved the synthetic THC medication dronabinol (sold under the brand names Marinol and Syndros) and a drug containing a synthetic substance similar to TCH known as nabilone (brand name Cesamet). Dronabinol is used to treat vomiting and nausea caused by chemotherapy and low appetite and weight loss caused by HIV/AIDS. Nabilone is used to also used to treat nausea and vomiting.
THC stimulates the release of a neurotransmitter called dopamine in the brain, which is what causes feelings of euphoria. The effects on the body can vary from one person to the next.
People may also experience:
We’re definitely not dealing with the same pot as we were in the past. This is because today’s marijuana is much more potent, with THC levels averaging 9.6%, according to the National Institute on Drug Abuse (NIDA). By comparison, in the early 1990s, marijuana generally had a THC level of about 4%.11
The strength of modern “high-potency” strains of marijuana, such as sinsemilla (“skunk”), was reportedly at least four times as strong, containing about 15% THC.11 The amount of THC contained in marijuana varies by the way that cannabis is prepared for use, such as leaf/bud, hashish, or hashish oil. THC levels can exceed 50% in products made from marijuana extracts.12
Cannabis has a long history of use that dates back thousands of years. The first recorded use of cannabis has been traced to China, where it was used for food, textiles, and medicine. Hemp was eventually introduced to Europe, and later to the Americas, where it came to use for both recreational and ritual purposes.
Cannabis was first introduced in the U.S. during the 1600s. Hemp was grown to produce textiles and was sometimes even used as legal tender. It was used for a number of medical purposes as well, but its recreational use began to grow during the 1930s and 1940s.
Around this time, anti-drug campaigns began against its use and many states passed laws prohibiting marijuana. The 1936 film “Reefer Madness” portrayed marijuana as a dangerous drug that led to psychosis, violence, and suicide.
In 1970, the Controlled Substances Act classified marijuana as a Schedule I drug, identifying it as having a high potential for abuse and making the drug illegal at the federal level.
The “war on drugs” launched during the 1970s led to the large-scale incarceration of many people for marijuana possession and use. Statistics suggest that the enforcement and penalization of marijuana laws disproportionately target people of color. While drug use has similar rates for people of all racial and ethnic backgrounds, Black and Latinx people are far more likely to be arrested and jailed for drug offenses.14
While it is still not legal at the federal level, many states have approved the use of cannabis and THC for medical and, in some states, recreational purposes. You should always check state laws where you live before purchasing any products containing THC.