What are synthetic cannabinoids?
“Synthetic cannabinoids” or “synthetic cannabis” (SC) are laboratory-made substances marketed by illicit manufacturers as being like THC (delta-9-tetrahydrocannabinol). THC is the main psychoactive chemical in the cannabis plant that can be smoked as cannabis or used in other cannabis products like edibles. Despite the resemblance in name, SC are not the same as plant-based cannabis and its chemical structures bear no resemblance to the chemical structure of plant-based THC from the cannabis plant. Unlike THC, SC are not one substance, but hundreds of different chemical combinations categorized in a new class of substances called novel psychoactive substances (NPS).
As early as the year 2000, SC were sold illegally to consumers in Europe and the USA via the internet, in convenience stores and smoke shops. SC are labeled falsely as “potpourri,” “herbal incense,” or “natural, herbal and legal” cannabis. Often, these products are marked with a disclaimer such as “not for human consumption” or “for aromatherapy use only” to avoid regulatory scrutiny. “K2” and “Spice” are two early SC products from which many new, modified products have been engineered and sold with new names. Typically, SC are marketed in appealing, brightly colored foil packets, with some featuring familiar children’s cartoon characters. These packets contain ground up greenish-brown plant material that has been sprayed with SC. From its original powder form, chemicals such as acetone and ethanol are used to dissolve the powdered SC into a liquid that subsequently is sprayed on and absorbed into the plant material.
In addition to the unregulated nature of SC, the plant material found in these products is neither uniform nor regulated for any type of quality control and may contain unidentified herbs with potentially harmful psychoactive properties. Even within individual packets, there may be different concentrations of chemical substances because the sprayed SC are not distributed evenly, leaving clumps or “hot spots” of SC.
If ingested, the effects of SC are more similar to those experienced from stimulants, like amphetamines, and may include many potentially serious adverse effects (see section below on SC general effects), in contrast to the milder effects typically associated with cannabis.Because of the misleading name, “synthetic cannabinoids,” used to market this group of substances, individuals seeking effects comparable to those effects commonly associated with plant-based cannabis may consume SC unknowingly and be harmed because of the increased potency and unpredictable effects. Reports compare SC potency to the potency of THC from the cannabis plant show tremendous variation, anywhere from 2–800x more potent depending on the type of SC compound.
The United States Drug Enforcement Agency (DEA) classifies SC as a Schedule I substance under the Controlled Substances Act, making this group of substances illegal federally as well as locally in New York State. It is illegal in New York State to possess, sell, offer to sell, or to manufacture SC.[Public Health Law Section 225, Title 10, Part 9.]
Young People & Synthetic Cannabinoids
Marketing for SC has targeted youth through enticing, playful packaging, and messaging SC as a cheaper alternative to cannabis that is not detected as easily in urine toxicology tests as THC. Both mental and physical health effects of SC use in youth may differ from adults with available studies suggesting greater harm.
Research on Youth SC Use
Estimates of 4.5 - 13.5 % of high school students, differing by geography, report lifetime use of SC versus 29% for cannabis alone.
- High school students who had used SC were more likely to engage in potentially harmful behaviors detrimental to their sexual and physical health compared to students who used cannabis only. 1
- Youth 12- 29 years old represent the largest age group of emergency room visits related to SC intoxication.
- Severe neurological effects like seizures or coma are more commonly seen with youth using SC versus cannabis only and more commonly seen in youth compared to adults. 2
How are synthetic cannabinoids typically used?
Most commonly, the plant material sprayed with SC is ground up and sold in foil packets or baggies and then rolled and smoked like a “joint.” Liquid versions of this substance also are sold in cartridges that may be vaped from an e-cigarette or other vaping devices. Additionally, SC may be ingested orally as a tea or swallowed and/or inserted rectally in capsule or tablet form. Like other psychoactive substances, for example LSD (lysergic acid diethylamide), SC may be ingested orally from blotter paper soaked with liquid SC. Overall, smoking or inhalation is the most popular route of use given its rapid onset of effect while oral ingestion causes a slower onset of effect.
Substances Mixed with Synthetic Cannabinoids
It also is not possible to predict accurately the potency of a purchased packet of SC by its appearance and There is no reliable method to detect other substances that may be mixed in with SC by visual inspection, smell or taste. Individuals who use SC should do so with caution given the likelihood that other chemicals may be present with unpredictable, potentially harmful effects.
- Substances mixed into SC may introduce additional harms to the individual who uses SC in addition to the potential harm related to SC alone. Globally, the type of substances detected have included an array of novel psychoactive substances or NPSs, including synthetic cathinones (“bath salts”), MDMA (”Ecstasy/Molly”) novel synthetic stimulants, and designer benzodiazepines.
- In addition, notable additives, such as vitamin E acetate, have been found in SC and are hypothesized to help mask SC detection in urine toxicology tests. The addition of vitamin E acetate is of particular concern given its association with many cases of e-cigarette or vaping product use-associated lung injury (EVALI).3 In 2018, a rat poison called brodifacoum caused life-threatening bleeding in clusters of individuals using SC.4 Flavorings like menthol or vanillin also may be added to increase appeal much like e-cigarettes' flavors used in the past.
Common Names for SC Products
K2, Spice, Kush, Scooby Snax, Green Giant, Geeked Up, Caution, Smacked, Wicked X, AK-47, Herbal Incense, Fake Weed, Yucatan Fire, Skunk, Moon Rocks, Fire, Aroma, Earth impact, Mr. Smiley, Mr. Nice Guy, Zohai, Black Mamba, Dream, and other names.
Effects from synthetic cannabinoid use
SC target the same areas of the brain as THC, particularly, the cannabinoid receptors named CB1 and CB2. However, the way in which SC interact with these brain receptors is very different from plant-based THC. The result is a significantly more intense and longer-lasting effect than THC in addition to other potential unanticipated adverse effects.
After inhaling SC by smoking or vaping, peak levels of SC are reached in 3 to 20 minutes with effects lasting from 3 – 5 hours to up to 24 hours. In some individuals, the duration of effects may be longer but unpredictable due to the continued activity from an array of SC break down products (metabolites).
General effects range from feelings of sedation, relaxation, and/or pleasant euphoria to anxiety, agitation, fatigue, problems with thinking and perception. Experiences differ depending on the individual using the substance, the type and amount of SC compound used, other psychoactive substances used together with SC, and the way in which it is consumed (for example, smoking vs. oral ingestion).
Mental and Physical Effects (mild to severe):
Potential mental health effects: Manic or psychosis-like conditions may result from SC use. From emergency room reports, mental health effects may present in several ways including severe anxiety, paranoia, auditory or visual hallucinations, agitation, sedation, and catatonia.
- Potential physical health effects:
- Cardiac or circulatory system: Tachycardia (rapid heart rate) and other arrythmias (abnormal heart rhythms), elevated blood pressure, heart attacks and strokes
- Nervous system: Seizures
- Kidney/urinary system: Severe kidney injury requiring hospitalization and a possible need for dialysis
- Gastrointestinal: Diarrhea, abdominal pain, dry mouth, and cannabis hyperemesis syndrome (persistent vomiting)
- Fatal and non-fatal overdoses involving SC also have been reported with individuals presenting with severe tachycardia, extreme agitation, and confusion.
- Increased risk of needing emergency services. Compared to people who use naturally occurring cannabis alone, people who use SC are up to 30 times more likely to require hospital emergency services because of severe reactions related to using SC.
Potential effects from chronic use may include:
- Difficulty with concentration
- Palpitations (feeling or sensation that the heart is pounding or racing)
- Panic attacks
Potential long-term effects
Long-term effects of chronic SC use are not understood completely and the impact of SC on cognitive, emotional, and physical functioning requires more study.
Can using synthetic cannabinoids lead to addiction?
Yes. Chronic use of SC may lead to physical dependence and addiction, formally known as Cannabis Use Disorder (CUD). Because SC are full agonists at the CB1 and CB2 receptors versus the limited partial agonist effects from THC, SC causes intense activation of these CB receptors. Therefore, when SC are used daily or almost daily for long periods of time and then stopped abruptly, an individual may experience several mild to moderate withdrawal symptoms including headache, stomach upset, sweating, difficulty sleeping, and anxiety. More severe symptoms include seizures, chest pain, palpitations, and shortness of breath. The severity of withdrawal symptoms may be related to the amount of SC used.
The criteria used to diagnosis a SUD include:
Needing to take more and more SC to get the desired effect
Using larger amounts of SC or over a longer period than you intended
Persistent desire or unsuccessful efforts to cut down on SC use
A lot of time spent doing things to get SC, use SC, or recover from its effects
Craving, or a strong need or desire to use SC
Failure to fulfill major role obligations at work, school, or home because of SC use
Continued SC use despite having persistent or recurrent social or interpersonal problems
Important things in life are given up because of SC use
Recurrent SC use in situations in which it is physically hazardous, such a driving a car or operating a machine
Continued SC use despite knowing its negative impacts on your mental or physical health (Adapted from the DSM-5-TR criteria for CUD)
How can I get help for myself or my loved one?
What can be done to reduce the potential harms of using synthetic cannabinoids?
Because the composition of SC is changing constantly with unpredictable potency and effects within and among batches of the same product, strategies aimed at reducing the potential harms associated with SC are recommended:
- Use small amounts of SC at a time if the full effect of using a particular SC is unknown.
- Avoid combinations of other substances with SC, including alcohol.
- Avoid operating vehicles or machinery while using SC.
- If using SC and/or other substances, use with a buddy in case of an unexpected physical or mental reaction.
- If using SC or other substances while alone, consider calling the overdose prevention hotline Neverusealone.org 1-800-484-3731 whose peers remain on the phone while the caller uses their substance, activating emergency services if an overdose or other severe reaction occurs.
- If an unexpected or severe reaction occurs, seek emergency medical services and bring the SC packet to the emergency room to assist with identification of the chemical substances ingested.
Which kinds of treatment work best for those who use synthetic cannabinoids?
- Emergency departments are the most appropriate setting to manage individuals with moderate to severe SC intoxication given the risk of severe or potentially life-threatening complications.
- Research studies demonstrating effective treatments (medications or other) for SC or cannabis use disorder are lacking. Two forms of psychological treatment used effectively to treat other SUDs, cognitive behavior therapy and contingency management, also may be helpful for people using SC.
- Medical and mental health providers may recommend individual or group counseling or behavioral therapy. These therapies exist in both the outpatient and inpatient treatment settings. Different levels of care are available for individuals seeking help, depending on their needs. Sometimes, an inpatient facility (rehabilitation) or residential program may be the best choice for more intensive treatment.
- It is important to discuss treatment options with medical or mental health treatment providers to see what may work best.
- Identifying and treating other co-existing substance use disorders and mental and physical health conditions related to SC use disorder are essential to maximize treatment options, reduce harms, and improve health outcomes.
Additional Resources for Help
The National Suicide and Crisis Lifeline: call or text 988
New York State Office of Drug User Health:
Health Resources Services Administration Poison Help Line: