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K2: What Is It? Who Uses It? And Why Is It So Dangerous?

Since the late 2000s K2, an extremely potent and deceptively cheap new drug also known as “spice,” has been wending its way into the systems of individuals across America. Between 2009 and 2015 calls to Poison Control Centers referencing K2 jumped from 14 to 3,572. Some areas of the country appear harder hit by the drug than others. In 2016 New York City experienced a reported 130 cases of K2 overdoses in a week. In 2018 New Haven, Connecticut, saw 95 reported overdoses over the course of two days. Since 2019 Washington, DC’s K2-related overdoses have increased by a whopping 128%, with over 1000 overdoses being reported in the capital in September of this year alone.

What is this drug and how does it affect the brain? Below, a closer look at the growing problem of K2 and how to address it.

What is K2 and what does it do?

K2 is one of several names for synthetic cannabinoids. It’s made by spraying man-made chemicals onto the shredded, dried material of plants. It’s known as a designer drug, meaning it’s composition is similar to but not exactly the same as cannabis (or marijuana). This renders it legal in states where cannabis is not—since its molecular structure differs from drugs classified as illicit). This also means that it affects the brain in ways similar to but far more potently than cannabis.

Synthetic cannabinoids act on the same receptors in the brain (cannabinoid receptors) that tetrahydrocannabinol (or THC, the active ingredient in marijuana) acts on—albeit more intensely. THC is a partial agonist for cannabinoid receptors, meaning that it binds to these receptors but elicits only a partial response. Synthetic cannabinoids are full agonists—meaning they elicit about as strong a response as possible, proving themselves to be up to 660 times more potent than cannabis according to some studies. They also bind to cannabinoid receptors more readily than THC. Their affinity for cannabinoid receptors is estimated to be 4-5 times greater than that of THC. Researchers believe that this accounts for synthetic cannabinoids’ greater association with psychiatric symptoms, including psychosis. Use of synthetic cannabinoids appears to elicit graver neuropsychiatric side effects than cannabis use. Psychosis, agitation and irritability, as well as anxiety are among the most common side effects associated with synthetic cannabinoid use. Other side effects of K2 use include seizures and convulsions, vomiting, an increased risk of having a stroke, elevated blood pressure, heart rhythm abnormalities (tachycardia and bradycardia) and chest pain, as well as kidney failure, heart attack and sometimes death.

Cannabinoid receptors are most abundant in our cerebral cortices, striatum, and hippocampus, areas of the brain involved in cognition, memory, and executive functions. Cannabinoid receptors are believed to play a strong role in our brain’s stress response system, specifically in inhibiting the perception of stress. (Indeed, stress relief is often cited as a reason for using cannabis and is a likely impetus to reach for K2—a cheap but more potent alternative). Unfortunately, chronic use of cannabis can downregulate (or desensitize) cannabis receptors, leading to abnormalities within the stress response system. This may explain the increased risk of psychosis and paranoia seen among frequent users of cannabis. Because synthetic cannabinoids act upon the same receptors in a more rapid and intense manner, their association with more severe psychotic symptoms and more intense worsening of psychiatric conditions like schizophrenia makes sense.

Where does K2 come from?

Cannabinoid receptors in the brain were discovered during the 1980s. This gave researchers the impetus to create synthetic cannabinoids in order to further study how these receptors responded to THC-like compounds and what role the endocannabinoid system played in range of human experiences, from stress and pain to sleep and appetite, as well as suppressing nausea. During the late 1980s and early 1990s scientists began manufacturing compounds that mimicked the physiological effects of cannabinoids. The most popular of these compounds was JWH-018, created by chemist John Huffman. Huffman never intended the product to be utilized as a street drug. But a group of savvy black-market drug developers got ahold of Huffman and other scientists’ research and drug manufacturing methods and began reproducing the synthetic cannabinoids for recreational use.

Recreational use of synthetic cannabinoids first spiked in Europe during the mid 2000s, then made its way to the United States by the early 2010s. For consumption they are typically dissolved in alcohol or acetone and sprayed onto dried, shredded plant material. Synthetic cannabinoids are concerningly easy to get ahold of. They are sold in small packages labeled as incense, potpourri, or herbal blends with a disclaimer stating their contents aren’t intended for human consumption. K2 is a popular brand name for synthetic cannabinoids. But they’re also sold under the names Spice, Black Mamba, and Scooby Snax.

Chemical components of each packet of synthetic cannabinoids are highly variable, which makes them very difficult to track, monitor, and continue to render illegal. Since 2010 synthetic cannabinoids have been classified by the United States Drug Enforcement Agency (DEA) as a Schedule I drug, meaning they have no accepted medical use and a high potential for abuse. However, their ever shifting makeup of synthetic cannabinoids means any newer strains contain chemicals that have yet to be classified as illegal. What’s more, some retailers have contested the DEA’s outlawing of synthetic cannabinoids on the basis that most for-sale versions contain the “not for human consumption” disclaimer on their packaging.

There’s another significant downside to the unpredictable and ever changing chemical composition of synthetic cannabinoids. Users never really know what they’re consuming when they opt to smoke products containing K2. This includes the kinds of chemicals they’re ingesting as well as the strength of such chemicals. What’s more, the unpredictability of synthetic cannabinoid strains’ chemical composition means that drug tests and toxicology screenings can’t detect them.

Who uses K2?

Use of synthetic cannabinoids appears to be more common among men in their 20s and 30s, many of whom may use this drug over others to avoid testing positive on drug screens. K2 also appears to be increasingly common among low-income individuals, especially in certain areas of the country, like New York State. High school and college students also appears to be more frequent users of K2, likely due to the ease with which K2 can be obtained as well as it’s lower cost, relative to other substances.

How is K2 use and abuse treated?

For cases of acute synthetic cannabinoid overdose, immediate treatment includes intravenous administration of fluids to treat electrolyte and fluid imbalances. Benzodiazepines are often used to treat mood symptoms resulting from K2 intoxication or withdrawal, like irritability, agitation, and anxiety. Benzodiazepines can also be used to treat seizures resulting from K2 use or withdrawal. Antiemetics are sometimes used, though with mixed results as far as efficacy goes, to curb excess vomiting induced by synthetic cannabinoid use.

Quetiapine, an antipsychotic, can also treat adverse mood symptoms resulting from K2 use in addition to treating psychotic-like side effects in individuals who do not respond to benzodiazepines. Other antipsychotics can help treat psychosis as well as agitation and mania.

Nabilone, an FDA-approved synthetic analogue of THC used to treat nausea caused by chemotherapy, has been found in some studies to reduce adverse outcomes of cannabis withdrawal and prevent relapse with chronic cannabis misuse. As such, some researchers believe this drug holds promise in treatment of K2 withdrawal. One case study published in 2014 found that Naltrexone, an opioid receptor antagonist used to treat opioid addiction, helped reduce cravings for synthetic cannabinoids.

In terms of long term management of chronic synthetic cannabinoid or K2 use, psychotherapeutic interventions used to treat other substance misuse disorders could be used to treat the issue. Research into longer term treatment specifically for K2 and other synthetic cannabinoids is scant; however, as more and more cases of chronic K2 use are reported by individuals seeking help for addiction, studies on the most effective modalities can only be expected to increase.

Currently some of the most effective treatments for substance misuse disorders include medication assisted therapies cognitive behavioral therapy, motivational interviewing, and trauma focused therapies.

If you or someone you know is struggling with an addiction to synthetic cannabinoids, don’t wait to get help. Repeated use of synthetic cannabinoids can cause severe and lasting damage to cognitive functioning, mental health, and physical health.


Photos Courtesy of Shutterstock.

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