What Is Synthetic Cannabinoid?

Synthetic cannabinoids are lab-made chemicals that act on the same brain receptors as THC, and NIDA says that use of illicit synthetic cannabinoids is associated with severe health problems and can be life-threatening. Many are sprayed onto dried plant material and smoked or sold as liquids for vaping. The lack of regulation makes them risky.

People report using these products because they were cheaper, easier to get and mostly missed by routine urine drug screens, NIDA says. Many do not know the products can cause severe side effects.

How Are Synthetic Cannabinoids Made?

Manufacturers create synthetic cannabis by altering chemical formulas to bypass laws. These substances do not come from the cannabis plant. Instead, they are made in labs, and many act on the same brain receptors as THC.

The chemicals are then sprayed onto plant material or dissolved into vape liquids. Unlike regulated products, these mixtures vary in strength and composition. Since recipes constantly change, synthetic marijuana can be unpredictable and dangerous.

How Do Synthetic Cannabinoids Work in the Body?

When consumed, many synthetic cannabinoids act on CB1 receptors in the brain, as THC does, and a 2015 review found that psychosis and psychosis-like conditions seem to occur relatively often after use, presumably because of their high potency.

The same review found that, compared with natural cannabis, synthetic cannabinoids may cause more frequent and more severe unwanted effects, especially in younger, inexperienced users. CDC lists violent behavior, confusion and seizures among the reported effects. Because the ingredients are unregulated, the same product can act very differently from one use to the next.

Effects of Synthetic Cannabinoids

The effects vary widely from one product to the next. Below are some of the most commonly reported effects users experience.

Intense Euphoria

People use synthetic marijuana for a high, but CDC says its chemicals are different from THC and can cause severe illness. Unlike natural cannabis, the reaction is unpredictable. Some feel excitement, while others face overwhelming distress and agitation.

• Rapid emotional shifts: CDC lists agitation and irritability among the effects on brain function.
• Restlessness and hyperactivity: CDC’s guidance for clinicians lists treatment for agitation, combativeness and muscular hyperactivity.

Hallucinations and Delusions

The mental effects can be severe. Some users experience frightening hallucinations or delusions, making it hard to distinguish between imagination and reality. In extreme cases, erratic behavior may pose risks to personal safety.

• Visual and auditory hallucinations: Users may see or hear things that are not real.
• Confusion and delusions: CDC also lists confusion, delusions and psychosis.

Physical Reactions

Synthetic cannabinoid products can severely impact the body, causing a range of harmful symptoms. Effects on the body include breathing problems, gastrointestinal problems, a fast heart rate, high blood pressure, heart attack, stroke, kidney failure and muscle damage, CDC says. Seizures and mental health risks are covered under Risks and Health Concerns below. Which effects appear depends on the chemicals in the product.

Risks and Health Concerns

NIDA warns that some of these risks can be life-threatening. Here are the most concerning dangers associated with these substances.

Severe Side Effects

The unregulated nature of synthetic cannabis means that active ingredients vary, leading to unpredictable reactions. Reported adverse effects include breathing problems, agitation, confusion and seizures, CDC says. The 2015 review found such unwanted effects may be more frequent and more severe than with natural cannabis.

Mental Health Risks

CDC lists hallucinations, delusions and suicidal thoughts among the effects on brain function. If you have thoughts of suicide, call or text the 988 Suicide & Crisis Lifeline now. Some people develop psychosis or psychosis-like conditions, the 2015 review found. The review suggests the likely reasons are the high potency of synthetic cannabinoids and the absence of CBD in these products.

• Unknown long-term effects: CDC says the effects of long-term use are unknown.
• Memory and concentration problems: CDC lists confusion and concentration problems; whether they last after long-term use is unknown.

Potential for Addiction

Long-term use of synthetic cannabinoids may cause dependence. People who suddenly stop after heavy use may have withdrawal symptoms such as headache, severe anxiety, sweating and trouble sleeping, CDC says.

Those withdrawal reports are why CDC says synthetic cannabinoids may be addictive. After frequent use, stopping suddenly has also brought severe symptoms such as seizures, a rapid heart rate and chest pain, CDC reports.

Legal Status of Synthetic Cannabinoids

Governments worldwide have imposed restrictions on synthetic cannabinoids due to their dangerous effects. However, manufacturers constantly alter their formulas to bypass regulations. In the United States, the DEA keeps placing new synthetic cannabinoids in Schedule I, the most restrictive federal category; a May 2026 rule added CUMYL-PEGACLONE.

Enforcement agencies struggle to keep up with new variants, making regulation difficult. The lack of oversight adds to the risks of synthetic marijuana, as users may unknowingly consume harmful chemicals.

Comparison to Natural Cannabinoids

Illicit synthetic cannabinoids are made in unregulated labs, unlike the FDA-approved lab-made cannabinoids dronabinol and nabilone, which are tested prescription drugs. The illicit versions are often full agonists at the CB1 receptor and more potent than THC. Illicit products have also contained dangerous additives: in 2018, CDC reported an outbreak of severe illness in Illinois linked to synthetic cannabinoids laced with brodifacoum, a rat poison.

In Florida, medical marijuana from licensed treatment centers must be lab tested for potency and contaminants before it is dispensed, and illicit synthetic products have no such testing. Without that testing, a buyer cannot know what an illicit product contains.

Recognizing and Avoiding Synthetic Cannabinoids

Spotting them can be difficult, since they are frequently advertised as incense made from herbs and “legal” cannabis alternatives. Packages are often unlabeled or mislabeled.

Consumers should avoid products with unclear ingredient lists or high-intensity effects. The purchase of cannabis from licensed dispensaries minimizes the chance of being exposed to synthetic forms. Whatever the package says, the label is no guide to what is inside.

Synthetic cannabinoids present serious health risks because of their unpredictability and lack of regulation. Because no one tests what is in them, they can contain harmful chemicals that may cause severe physical and mental reactions. If you or someone you know has severe symptoms after using one of these products, call 911 or Poison Control at 1-800-222-1222.

Last updated October 18, 2026 by the Dr. Green Relief Editorial Team.

Sources

• NIDA. Synthetic Cannabinoids
• van Amsterdam J, et al. The adverse health effects of synthetic cannabinoids with emphasis on psychosis-like effects. J Psychopharmacol. 2015
• Moritz E, et al. Notes from the Field: Outbreak of Severe Illness Linked to the Vitamin K Antagonist Brodifacoum and Use of Synthetic Cannabinoids, Illinois, March to April 2018. MMWR. 2018
• Federal Register (May 13, 2026). Schedules of Controlled Substances: Placement of CUMYL-PEGACLONE in Schedule I
• Florida Statutes, s. 381.986, Medical use of marijuana
• CDC (archived). About Synthetic Cannabinoids
• CDC (archived). Synthetic Cannabinoids (Spice): An Overview for Healthcare Providers