NEWS

What Is THC? How It Gets You High and What It's Used For

The molecule behind the high: how THC hits your brain, what patients use it for and how long it lingers in your blood.

BY CosechaLibre Editorial5 MIN READ

What is THC?

THC stands for tetrahydrocannabinol, or delta-9-tetrahydrocannabinol. It's a cannabinoid molecule in marijuana (cannabis) and the plant's main psychoactive ingredient: the compound that gets people high when they smoke, vape or eat weed.

THC is just one of more than 500 active compounds found in cannabis so far, over 100 of them cannabinoids. Hands down, THC is the best-known cannabinoid. The other big one, famous for its therapeutic potential, is cannabidiol (CBD).

Close-up of THC-rich trichomes on a cannabis bud

How does THC work in the body?

THC works by binding to the body's cannabinoid receptors, which are spread throughout the brain and nervous system. THC sticks around in the body far longer than most other drug compounds (days for occasional users, longer for regulars), even though the high itself only lasts a few hours.

Cannabinoid receptors are packed into brain areas tied to thinking, memory, pleasure, coordination and time perception. THC latches onto these receptors, switches them on and shifts a person's memory, pleasure, movement, thinking, focus, coordination and sense of time and senses.

THC prompts brain cells to release dopamine, which is where the euphoria comes from. It also messes with how information gets processed in the hippocampus, the part of the brain in charge of forming new memories.

What is THC used for?

THC is used recreationally, but it also has a range of medical uses. People have used cannabis as medicine for thousands of years, but research into using it to relieve and treat illness is still fairly young, even if it's moving fast.

Conditions patients use THC for, and researchers are studying, include:

Anxiety
Depression
Glaucoma
Inflammation
Inflammatory bowel disease (IBD)
Insomnia
Irritable bowel syndrome (IBS)
Migraines
Multiple sclerosis
Muscle spasticity
Nausea
Pain
Poor appetite
Post-traumatic stress disorder (PTSD)
Seizures
Symptoms linked to HIV/AIDS

How much THC is in weed today?

THC levels in weed aren't what they used to be. Marijuana has gotten much stronger, with THC levels averaging 9.6% in figures from the National Institute on Drug Abuse (NIDA), and more recent potency data puts the average higher still. For comparison, in the early 1990s weed usually tested at around 4% THC.

Can THC be detected in your blood?

Yes, THC shows up in the blood after you consume cannabis. How long it stays there depends on several factors: how much you used, how often you use, and your age, body weight and metabolism.

As a rule of thumb, THC can be detected in the blood for up to 1-2 days after occasional use, but in regular and heavy users it can show up for several weeks.

Keep in mind that blood THC levels don't necessarily line up with how intoxicated someone is or how strong the effects feel. That's because THC is stored in the body's fat tissue and slowly released back into the bloodstream over time. So someone can have detectable THC in their blood without being high or feeling any psychoactive effects.

What's the difference between THC and CBD?

Both belong to the same family of chemical compounds, the cannabinoids, but they differ a lot in their effects and properties.

THC is cannabis's main psychoactive compound, meaning it's responsible for the "high" or euphoric buzz people associate with weed. It binds to cannabinoid receptors in the brain and body to produce a range of effects, including shifts in mood, perception, memory and motor coordination.

CBD, on the other hand, doesn't get you high. Instead, it has potential therapeutic properties and has been used for a range of medical conditions, including epilepsy, anxiety and chronic pain. Research also suggests CBD can take the edge off some of THC's psychoactive effects, which can help people who want cannabis's medical benefits without feeling stoned.

Conditions CBD is used to help with or ease:

Seizures
Inflammation
Pain
Psychosis and other mental health conditions
Inflammatory bowel disease
Nausea
Migraine
Depression
Anxiety

CBD can be taken by mouth or applied to the skin, depending on the product. There are tons of options, from oils and softgels marketed for anxiety to relaxing bath salts, creams and lotions. You can smoke it too, of course, but if you're using CBD for therapeutic or medical reasons, it's best to skip combustion and go with healthier formats.

Several studies show that CBD has a strong anticonvulsant effect that works well in certain types of epilepsy, and its use has grown fast because it doesn't get you high.

Thanks to modern breeding, you can grow strains that contain almost only CBD, without having to take in much THC, the cannabinoid that does have psychoactive effects.

The bottom line on THC

THC is the active ingredient in weed that gets you high. Some studies suggest it can ease chronic pain and other health problems.

That said, THC isn't for everyone: for some people it can cause trouble, and while there's no known fatal THC overdose, taking too much can trigger unpleasant side effects like paranoia, anxiety, dry mouth, and nausea or vomiting.