What to Know About Synthetic Marijuana (Fake Weed) Use
Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.
Synthetic cannabinoids, also called synthetic marijuana or fake weed, have been used by many as an alternative to marijuana since products were first introduced in 2002. Despite the fact that these man-made products were created in laboratories to help scientists study the cannabinoid system in the human brain, they often claim to be made of “natural” material from a variety of plants.
Hundreds of synthetic cannabinoids exist and the effects can be unpredictable and even life-threatening.
Also Known As: There are countless fake weed products being sold as herbal smoking blends, legal bud, herbal smoke, marijuana alternatives, fake weed, or herbal buds. This makes it difficult for parents and other adults to identify them. Some of the brand names include Blaze, Blueberry Haze, Dank, Demon Passion Smoke, Genie, Hawaiian Hybrid, K2, Magma, Ninja, Nitro, Ono Budz, Panama Red Ball, Puff, Sativah Herbal Smoke, Skunk, Spice, Ultra Chronic, and Voodoo Spice.
Drug Class: Synthetic marijuana products are classified as new psychoactive substances (NPS), or unregulated mind-altering substances intended to produce the same effects as illegal drugs.
Common Side Effects: Side effects of the drug include elevated mood, relaxation, altered perception, symptoms of psychosis, extreme anxiety, confusion, paranoia, hallucinations, violent behavior, suicidal thoughts, rapid heart rate, raised blood pressure, vomiting, kidney damage, and seizures.
How to Recognize Fake Weed
Synthetic marijuana often contains a mixture of dried leaves from traditional herbal plants. They are various colors, including green, brown, blonde, and red, and often sold in small packets approximately two by three inches. The packets are often colorful foil packs or plastic zip bags. Some online sellers of legal fake weed products do so with disclaimers like “not for human consumption.”
What Does Synthetic Marijuana Do?
Fake weed works on the same brain cell receptors as THC or delta-9-tetrahydrocannabinol (the psychoactive ingredient in marijuana that gets you high). It is typically smoked, brewed in tea, or vaped. Many of these products are legally marketed as “herbal incense” or “potpourri”.
Some people who use herbal buds say that it produces a high similar to that of marijuana, but it doesn’t last as long. Others experience a relaxed feeling, rather than the “head high” that real marijuana produces. Also of note is the “harsh” taste, which people say “makes your throat burn and your lungs ache” long after you smoke.
Since there are no standards for making, packaging, or selling synthetic weed, it’s impossible to know the type and amount of chemicals in each product as well as what the fake weed will do to you.
What the Experts Say
Although they are often marketed as “100% organic herbs,” none of the fake weed products on the market are completely natural. They have all been found to contain various synthetic cannabinoids, or chemicals produced in laboratories.
Originally, fake marijuana products contained a chemical called HU-210, which has a molecular structure very similar to THC. Because HU-210 is listed as a Schedule I controlled substance in the United States, these fake weed products were manufactured and sold only in Europe.
Since then, new synthetic cannabinoid agonists have been created. They are too numerous to list. Some are similar in structure to THC; others are not. Some are classified as controlled substances. By using different synthetic marijuana mixtures, manufacturers are able to continue to legally market their products in the United States when another formulation becomes illegal.
According to the DEA, the majority of these chemical compounds are produced in Asia with no regulations or standards. They are then smuggled into the United States where they are sprinkled onto “plant material,” packaged and ultimately sold in tobacco shops, convenience stores, and the like.
Some of these chemicals are still legal. However, since synthetic marijuana first hit the market, more than 20 of these compounds have become controlled in some way at the federal level. At the same time, they noted that more than 75 additional compounds have been identified but are not currently controlled.
In 2015, the DEA listed 15 varieties of synthetic marijuana as Schedule I controlled substances in the Drugs of Abuse resource guide. This places them in the same federal category as heroin, crack cocaine, and marijuana.
Many people buy into the idea that fake marijuana products are safe since the chemicals are “legal” and contain “natural” ingredients. However, this has proven to be false with multiple cases of severe, unexplained bleeding or bruising, and some deaths. Other reports show an increase in emergency room visits due to rapid heart rate, vomiting, violent behavior, suicidal thoughts, kidney damage, and seizures.
Some of the fake marijuana products sold commercially claim to contain herbs traditionally used for medicinal purposes, including:
- Beach bean (Canavalia maritima)
- Blue Egyptian water lily (nymphaea caerulea)
- Dwarf skullcap (scutellaria nana)
- Indian warrior (pedicularis densiflora)
- Lion’s tail (leonotis leonurus)
- Indian lotus (nelumbo nucifera)
- Honeyweed (leonurus sibiricus)
However, one study revealed that some of the herbal ingredients listed by the manufacturers could not be found in the products.
Beyond the synthetic cannibinoid HU-210, which is used by scientists to identify cannibinoid receptors in the brain and study the effects Δ-9-tetrahydrocannabinol (Δ-9-THC), there are no approved or off-label medical uses for synthetic marijuana.
Common Side Effects
While research is advancing, the effect synthetic marijuana products may have on the human body is largely unknown. To date, few studies have been published testing the effects of the chemicals on users. Within the DEA report, they note overdoses that have caused fatal heart attacks. Similarly, acute kidney injury resulting in hospitalization and dialysis have been connected to these synthetics.
One study compared the level of impairment for drivers who were arrested for intoxicated driving. One group had smoked synthetic cannabinoids and those in the other group were high on marijuana. The study found a significant increase in confusion, disorientation, and incoherence in the synthetic marijuana group. Slurred speech, a side effect not normally associated with natural cannabis use, was also reported among the synthetic cannabinoid users.
Beyond the short-term effects mentioned, an increase in blood pressure, as well as seizures, tremors, and anxiety, have been noted in synthetic marijuana users.
Whether these observed symptoms will have lasting effects, particularly on adolescents and young adult users, is not yet known. Of course, smoking any substance could have negative effects on the lungs.
“The problem with JWH-018 (a synthetic cannabinoid compound) is that absolutely nothing is known regarding its toxicity or metabolites,” says John Huffman, who helped develop the JWH-018 chemical. “Therefore, it is potentially dangerous and should not be used.” JWH-018 is also known as 1-Pentyl-3-(1-naphthyl) indole and is one of the Schedule I controlled substances listed with the DEA.
Recently, a version of synthetic marijuana was laced with rat poison, causing uncontrolled bleeding in hundreds of people and killing several others who ingested the tainted products.
If you or a loved one has used synthetic marijuana and begin experiencing severe, unexplained bleeding or bruising, call 911 or asked a loved one to take you to the hospital immediately. These are all signs of contaminated cannabinoid products.
Signs of Use
If you are a parent of a young adult, it pays to know the behaviors and physical effects of using fake weed. While exhibiting one or two of these signs might not mean that your child is using, they are all strong indicators of drug use and should be taken seriously.
- Burning incense
- Buying or using eye drops
- Possessing dried plants or herbs
- Having rolling papers or vape pens
- Receiving suspicious packages in the mail
- Displaying unusual or secretive behaviors
- Red or irritated eyes
- Pale complexion
- Acting confused
Myths and Common Questions
Perhaps one of the biggest misconceptions about herbal bud is that it is “natural marijuana.” It is not; it is created from any of several hundred man-made synthetic chemicals that are sprayed onto the chopped plant material.
Synthetic marijuana is also far more potent, containing TCH analogs or synthetic cannabinoids that can be up to 600 times more potent than THC found in marijuana. Often, additives, toxic impurities, and other types of drugs are also found in fake weed products.
Tolerance, Dependence, and Withdrawal
Regularly using “fake weed” can result in increased tolerance, or needing more and more of the drug to experience the same high. If you regularly use synthetic cannabinoids, you can also become both physically and psychologically dependent. This means if you stop abruptly, you’ll likely experience withdrawal symptoms.
Since the chemical composition of fake weed is unknown and can change from batch to batch, tolerance, dependence, and withdrawal may also vary.
How Long Does Fake Weed Stay in Your System?
How long synthetic cannabinoids stay in your system depends on several factors, including the type, how it is administered (i.e., inhaled or ingested), amount consumed, and frequency of use. Since these synthetic drugs don’t trigger a positive result on most standard urine drug tests , many people turn to these drugs in an attempt to avoid positive drug screens for employment, rehab, or legal reasons.
Long-term, regular use of synthetic cannabinoids can lead to addiction. If you have a history of mental illness or a substance use disorder, the risk of addiction is even greater.
In addition to building up a tolerance and experiencing symptoms of withdrawal, other signs of synthetic cannabinoid addiction can include:
- You use more than intended, even after telling yourself that you’ll only “take a few hits.”
- You are unable to cut down or stop and have likely failed numerous times at quitting.
- You spend lots of time getting high, often at the expense of spending time with loved ones or doing activities you once enjoyed.
- You continue to use despite any problems with family and friends, employment, or legal troubles.
- You depend on the drug to “relax” or for creativity.
Symptoms of synthetic weed withdrawal can range from mild to severe, depending on how frequent and how long you have been using, and include the following:
- Severe anxiety
How to Get Help
If you suspect that someone you love is using synthetic marijuana, the most important thing you can do is spend time with them, communicate the dangers of fake weed, and watch for any signs of use. While behavioral therapies and medications have yet to be specifically tested for the treatment of synthetic cannabinoid addiction, a health care professional can work with you and your loved one to safely detox from the drug as well as identify and treat any co-occurring mental illness.
In addition to getting a recommendation from a trusted health care professional, the Partnership at DrugFree.org has a helpline and tips so families know what to ask when vetting a rehab.
If you or a loved one are struggling with substance use or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.
For more mental health resources, see our National Helpline Database.
Learn what experts have to say about synthetic marijuana or "fake weed" as well as common side effects, myths, signs of use, and risk for addiction.
Synthetic Cannabinoids (K2/Spice) DrugFacts
What are synthetic cannabinoids?
Synthetic cannabinoids are human-made mind-altering chemicals that are either sprayed on dried, shredded plant material so they can be smoked or sold as liquids to be vaporized and inhaled in e-cigarettes and other devices. These products are also known as herbal or liquid incense.
These chemicals are called cannabinoids because they are similar to chemicals found in the marijuana plant. Because of this similarity, synthetic cannabinoids are sometimes misleadingly called synthetic marijuana (or fake weed), and they are often marketed as safe, legal alternatives to that drug. In fact, they are not safe and may affect the brain much more powerfully than marijuana; their actual effects can be unpredictable and, in some cases, more dangerous or even life-threatening.
Synthetic cannabinoids are part of a group of drugs called new psychoactive substances (NPS). NPS are unregulated mind-altering substances that have become newly available on the market and are intended to produce the same effects as illegal drugs. Some of these substances may have been around for years but have reentered the market in altered chemical forms, or due to renewed popularity.
Synthetic cannabinoid products are often labeled “not for human consumption.” Labels also often claim that they contain natural material taken from a variety of plants. However, the only parts of these products that are natural are the dried plant materials. Chemical tests show that the active, mind-altering ingredients are cannabinoid compounds made in laboratories.
Manufacturers sell these products in colorful foil packages and plastic bottles to attract consumers. They market these products under a wide variety of specific brand names. Hundreds of brands now exist, including K2, Spice, Joker, Black Mamba, Kush, and Kronic.
For several years, synthetic cannabinoid mixtures have been easy to buy in drug paraphernalia shops, novelty stores, gas stations, and over the internet. Because the chemicals used in them have no medical benefit and a high potential for abuse, authorities have made it illegal to sell, buy, or possess some of these chemicals. However, manufacturers try to sidestep these laws by changing the chemical formulas in their mixtures.
Easy access and the belief that synthetic cannabinoid products are natural and therefore harmless, have likely contributed to their use among young people. Another reason for their continued use is that standard drug tests cannot easily detect many of the chemicals used in these products.
How do people use synthetic cannabinoids?
The most common way to use synthetic cannabinoids is to smoke the dried plant material. Users also mix the sprayed plant material with marijuana or brew it as tea. Other users buy synthetic cannabinoid products as liquids to vaporize in e-cigarettes.
How do synthetic cannabinoids affect the brain?
Synthetic cannabinoids act on the same brain cell receptors as THC (delta-9-tetrahydrocannabinol), the mind-altering ingredient in marijuana.
So far, there have been few scientific studies of the effects of synthetic cannabinoids on the human brain, but researchers do know that some of them bind more strongly than marijuana to the cell receptors affected by THC and can produce much stronger effects. The resulting health effects can be unpredictable and dangerous.
Because the chemical composition of many synthetic cannabinoid products is unknown and may change from batch to batch, these products are likely to contain substances that cause dramatically different effects than the user might expect.
Synthetic cannabinoid users report some effects similar to those produced by marijuana:
- elevated mood
- altered perception—awareness of surrounding objects and conditions
- symptoms of psychosis—delusional or disordered thinking detached from reality
Psychotic effects include:
- extreme anxiety
- paranoia—extreme and unreasonable distrust of others
- hallucinations—sensations and images that seem real though they are not
What are some other health effects of synthetic cannabinoids?
People who have used synthetic cannabinoids and have been taken to emergency rooms have shown severe effects including:
- rapid heart rate
- violent behavior
- suicidal thoughts
Are synthetic cannabinoids addictive?
Yes, synthetic cannabinoids can be addictive. Regular users trying to quit may have the following withdrawal symptoms:
Behavioral therapies and medications have not specifically been tested for treatment of addiction to these products. Health care providers should screen patients for possible co-occurring mental health conditions.
Can you overdose on synthetic cannabinoids?
Yes. An overdose occurs when a person uses too much of a drug and has a dangerous reaction that results in serious, harmful symptoms or death. Use of synthetic cannabinoids can cause:
- toxic reactions
- elevated blood pressure
- reduced blood supply to the heart
- kidney damage
Deaths can also occur when dangerous synthetic opioids, such as fentanyl, are added to the packaged mixture without the user knowing it.
Points to Remember
- Synthetic cannabinoids refer to a growing number of human-made mind-altering chemicals sprayed on dried, shredded plant material or vaporized to produce a high.
- Synthetic cannabinoids are sometimes misleadingly called synthetic marijuana (or fake weed) because they act on the same brain cell receptors as THC, the mind-altering ingredient in marijuana.
- The effects of synthetic cannabinoids can be unpredictable and severe or even life-threatening.
- The only parts of synthetic cannabinoid products that are natural are the dried plant materials. Chemical tests show that their active ingredients are human-made cannabinoid compounds.
- Synthetic cannabinoid users report some effects similar to those produced by marijuana:
- elevated mood
- altered perception
- symptoms of psychosis
- Synthetic cannabinoids can also cause serious mental and physical health problems including:
- rapid heart rate
- violent behavior
- suicidal thoughts
- Synthetic cannabinoids can be addictive.
- Behavioral therapies and medications have not specifically been tested for treatment of addiction to these products.
- Overdoses can occur and can cause:
- toxic reactions
- raised blood pressure
- reduced blood supply to the heart
- kidney damage
- Deaths can occur when dangerous synthetic opioids, such as fentanyl, are added without the user knowing.
For additional information about synthetic cannabinoids, visit:
- NIDA for Teens Drug Facts on Spice – Offers resources for teens and teen influencers. Get the latest on how drugs affect the brain and body. Features videos, games, blog posts, and more!
- Easy-to-Read Drug Facts on Spice (K2) – Has pictures and videos to help readers understand the text. The website also can read each page out loud.
A plain language summary of synthetic cannabinoids, how they are used, and how they affect the brain and body.