THC is a cannabinoid, a category of chemicals that interact with the body's endocannabinoid system. By attaching to cannabinoid receptors in the brain, THC activates neurons that influence pleasure, memory, thinking, coordination, and time perception.

Some research and anecdotal evidence indicate THC may be used to treat a range of medical conditions. And from a recreational standpoint, it can feel good, causing a sensation of euphoria and relaxation in some.
Here is what you need to know about THC from how it differs from CBD to its therapeutic uses.
CBD vs. THC
After THC, CBD is the most prevalent cannabinoid in marijuana.
Unlike THC, CBD won't get you high. That's because CBD does not stimulate cannabinoid receptors in the brain like THC, says Jordan Tishler, MD, President of the Association of Cannabis Specialists. Instead, it changes how those receptors react to THC. For example, researchers have found CBD can weaken THC's anxiety-causing effects.
Another difference between THC and CBD is legality. In the United States, cannabis is federally illegal. However, on the state level legality varies:
16 states, Guam, Puerto Rico, and the District of Columbia have legalized small amounts of marijuana for recreational use
27 states and the District of Columbia have decriminalized small amounts of marijuana
19 states have legalized medical marijuana only
As for CBD's legality? It's complicated.
CBD from industrial hemp (or cannabis with less than 0.3% THC) is legal, but CBD obtained from marijuana (cannabis with more than 0.3% THC) can only be used in states where weed is legal.
Important: The drugs Marinol and Syndros contain a synthetic form of THC and are available by prescription to treat nausea and vomiting caused by chemotherapy, as well as stimulate appetite and weight loss in people with HIV/AIDs.
How long does THC stay in your body?
THC will build up in your system over time, so how frequently you use THC determines how long it remains in your body. In general, THC can be detected in infrequent users for one to three days after last use and 30 days or longer in chronic users. Your method of consumption plays a role, too: For example, your body takes longer to process the THC in an edible, meaning it will stay in your system longer than vaping or smoking.
Important: Contrary to popular belief, you can't flush THC out of your system by sweating or drinking water, but experts say the only way to detox THC is by waiting it out and stopping use.
Benefits of THC
THC is used medicinally to relieve symptoms of certain conditions. But, because cannabis is federally illegal in the United States, research on THC is significantly limited.
"Most of the clinical data we have is anecdotal evidence or evidence from practitioners in states where they allow medical marijuana," says Amol Soin, MD, the medical director of the Ohio Pain Clinic and member of the Ohio Medical Marijuana board. "Marijuana is a [DEA] schedule one substance, which eliminates the ability to do a lot of clinical trial work."
Here are some of the emerging benefits, researchers have found so far:
Alleviates pain
Chronic pain relief is the most common reason why people seek medical marijuana. A large 2015 systematic review evaluated cannabis studies in patients with chronic pain and found THC increased the odds for pain improvement by around 40%.
While clinical trials support the use of cannabis for chronic pain, researchers agree more studies are needed to determine what doses, forms, and combinations of cannabinoids are most therapeutic for chronic pain patients.
Reduces nausea from chemotherapy
Two oral THC-containing drugs — nabilone and dronabinol — have been available for the treatment of chemotherapy-induced nausea and vomiting for more than 30 years.
A small 2010 study of chemo patients found those who took a THC-containing medicine in combination with standard treatment experienced stronger protection against nausea and vomiting than patients who received the standard treatment alone.
Reduces muscle spasms in paraplegics
Studies suggest THC products can modestly reduce muscle spasms, a common symptom experienced by people with Multiple Sclerosis (MS) and paraplegia.
In fact, a large 2015 systematic review concluded that THC used in combination with other cannabinoids improved self-reported muscle spasms more than a placebo, although the difference was not statistically significant.
Improves sleep
Sleep disturbances are typical in people living with health problems like MS and chronic pain. Studies in these groups show THC products can improve short-term sleep problems, reduce sleep disturbances, and decrease the time it takes to fall asleep. However, it's unclear whether the THC directly affects sleep quality or whether sleep is improved because chronic symptoms were reduced.
Health Risks of THC
Brain imaging studies have revealed that daily exposure to THC in adolescence is linked to altered connectivity and reduced volumes in brain regions responsible for memory, learning, and impulse control. Recent studies also suggest that long-term use of THC-based products can cause permanent IQ loss of six to eight points, especially when THC use starts during adolescence and progresses into adulthood.
Although a fatal overdose on THC is unlikely, the consumption of too much THC can cause negative reactions such as:
Extreme confusion
Anxiety
Paranoia
Fast heartbeat
Delusions or hallucinations
Increased blood pressure
Severe nausea or vomiting
These negative reactions can sometimes result in unintentional injuries such as a motor vehicle crash, fall, or poisoning.
Another health risk of THC is dependence. Since THC triggers a surge of dopamine, it reinforces substance-seeking behavior that increases the risk of physical dependence. According to the Substance Abuse and Mental Health Services Administration (SAMHSA), around one in 10 people who use marijuana experience dependence. And this increases to one in six when its use starts before the age of 18. Individuals with a dependence on THC may face various unpleasant withdrawal symptoms during detox.
THC Withdrawal Treatment and Management
Although THC detox rarely causes any life-threatening withdrawal symptoms, it’s advisable to seek professional support to detox from THC to ensure success and long-term abstinence. This is especially true for people who have experienced a relapse before, practice poly-substance misuse, have a history of mental health disorders, or have other significant medical conditions.
Resources to help you through your THC detox include:
Detoxification Centers – These centers offer short-term detox programs that provide constant assistance and medical attention.
Inpatient Rehabilitation Centers – These centers provide round-the-clock supervision and care for more than 25 days to help people quit using substances, including THC-based products, and manage the underlying conditions that led to substance misuse.
Intensive Outpatient Centers – Intensive outpatient programs help people overcome their dependence on THC and address the underlying root causes of their substance use disorder. However, these centers operate in the morning or evening and do not require people to reside at the facility like inpatient services. Individuals must meet multiple times a week for a few hours to engage in counseling and behavioral therapies.
Best THC Detox Tips
In addition to seeking professional support, it’s also a good idea to follow the self-care methods listed below:
Drink plenty of water and avoid caffeinated or sugary beverages like soda.
Avoid processed and greasy foods that make you feel sluggish and irritable. Instead, have healthy foods such as vegetables, fruits, and lean meat to fuel the body.
Ensure to exercise for at least 30 minutes a day.
Spend ample time around people who support you and join support groups to find like-minded people in recovery who can help you through your journey.