While there hundreds of active ingredients in the cannabis plant, few have received so much attention as tetrahydrocannabinol, or just “THC”. This psychoactive cannabinoid was discovered in 1964 by Israeli scientist Dr. Raphael Mechoulam and has taken center stage in the cannabis world. Could this popular cannabinoid be right for you? Read on to learn more.

What is THC, or tetrahydrocannabinol, and is it right for me?

THC, or tetrahydrocannabinol is the most common cannabinoid in marijuana. It is the ingredient that gives cannabis its psychoactive effects, and is one of the most powerful parts of the plant when it comes to its medicinal benefits. Like any chemical substance — there can be side effects and people it’s not right for.  Some find the side effects of THC overwhelming, and it is contraindicated for certain conditions.

Will THC make me feel ‘high’?

Yes. THC is a psychoactive substance that can cause temporary changes in mood. A common effect is feelings of well-being, called “euphoria”, or a “high” in slang terms. If you find the “high”  of THC overwhelming, supplementing it with cannabidiol (another cannabinoid found in cannabis) can help lessen this effect. People can react to THC in different ways. If you take too much of certain types of cannabis high in THC — you may experience temporary negative side effects like anxiety, dry mouth, increased heart-rate or difficulty concentrating. Cannabis can make people temporarily dizzy, or forgetful, and can potentially be habit-forming.

What is THC being used for?

THC has many uses. The most common reason patients use cannabis is for pain relief, and THC plays a big role. While other ingredients in cannabis can reduce pain, studies show THC offers the greatest pain reductions. Patients also use THC for depression and anxiety, nausea, spasms, and sleep disorders, along with other conditions.  

Where does THC come from?

THC comes from the cannabis plant, but it can also be made synthetically. There are some synthetic THC products out there, such as the prescribed drug Marinol. Unlike cannabis, Marinol is approved by the FDA, but it has a few drawbacks compared to cannabis derived THC. Patients report that cannabis simply works better for them than synthetic marinol. This is in part because cannabis usually contains a variety of compounds that work together to create an “entourage effect”. Marinol has synthetic THC only, and patients report negative side effects that aren’t present with cannabis.

How do I find THC?

You can find THC in most states with recreational or medical cannabis laws. California, Washington, Colorado and Oregon are all examples of places where you can purchase THC without first getting a doctor’s recommendation. Licensed stores can be located through store finders like our California map, as well as providers like WeedMaps and GetMeadow and other web sites.

How do I take THC?

THC can be inhaled, taken sublingually, eaten or used as a topical. Be aware that when you eat THC your liver converts the molecule into delta 11-THC. This is a different drug which last longer and can affect you differently. Inhaled THC takes effect in under one minute and lasts about 90 minutes. Eaten THC can require two hours to take effect and last for eight hours or longer.

Most licensed, and regulated products are labeled with the amount of THC in them in milligrams, or the percentage THC by dry weight of flower or extract. Generally speaking, 0 to 8 percent THC flowers are considered mild, 8 – 14 percent THC flowers are considered moderate strength, and anything higher than 14 percent THC can have strong effects on a cannabis-naive individual. Extracts of cannabis can reach into 70, 80, or 90 percent THC.

What is one dose of THC?

Officially a dose is 10 milligrams, but the right dosing for THC depends greatly on the person taking it and the condition it is being taken for. It is best to start with a small does like 2.5 milligrams. This can be very effective for many conditions, but some may need much larger doses. Start small and work your way up until you find a dose that works for you.

Who should not use THC?

THC can be contraindicated for some conditions. People with a family history of schizophrenia or other mental illnesses should be aware that THC — like other drugs including alcohol — can worsen that condition. THC can also lower blood pressure and raise heart-rates so people with certain heart conditions may be at increased risk.

Doctors advise women who are pregnant or breastfeeding to not use THC. THC is generally not recommended for people with substance use disorders, including cannabis use disorder. THC is also inappropriate for juveniles, whose brain’s reward systems are still developing. Juvenile cannabis use is associated with increased likelihood of cannabis use disorders in adulthood.

Do not combine THC with other drugs including alcohol. Talk to a physician who is specialized in cannabinoids to find out if THC is safe for you.  

What is the law around THC?

THC is considered a “Schedule 1 drug” in the US, alongside heroin and PCP, and is deemed medically useless with a high potential for abuse. THC is only legal in states that have legalized marijuana for medical or recreational purposes. THC remains illegal federally and people who possess it can be stopped and arrested where federal officials are operating, especially at the U.S. land border and airport customs. Workers who use THC don’t have workplace employment rights, so you can lawfully be fired for off-duty cannabis use. Many employers routinely screen employees’ urine for markers of THC use called “metabolites” that stay in the body up to six weeks.

How do I get rid of THC in my body?

While THC is out of the body in less than a day, employers test for a THC metabolite called “THC-COOH” that can stay in fat cells up to six weeks, depending on frequency of use and other factors. The only sure way to remove THC-COOH from the body is to discontinue THC use and allow enough time to pass for metabolites to clear one’s system.

What is synthetic THC?

Due to drug testing, many individuals who are regularly drug tested — like members of the military — will seek out unregulated chemicals deemed “synthetic THC” to get cannabis’ effects without failing a drug test. Chemicals considered “synthetic THC” are often foreign-made drugs that act on the same electro-chemical signalling system in nerves, called the endocannabinoid system. However, “synthetic THC” chemicals are often hundreds or thousands of times stronger than THC and can cause severe, lifelong injury and often death. Never use synthetic THC products.

Got any more questions about THC or other medical cannabis modalities? Email GreenState editor ddowns@sfchronicle.com or message us on Facebook.

Emily Earlenbaugh, PhD is a cannabis writer and educator. She holds a doctorate in the philosophy of science from UC Davis.