K2/Spice Side Effects, Overdose & Withdrawal

Last Updated: January 6, 2021

Authored by Isaak Stotts, LP

Reviewed by Tania Kelly

While marijuana legalization is slowly seeing some progress, a so-called natural marijuana alternative with the street name Spice, aka K2, is more readily available. It’s usually a plant material coated with synthetic cannabinoids or other similar substances, which a person can smoke, and offers a high.

Contrary to popular belief, the Spice is not safe and can have many serious side effects on one’s health. On top of that, it can be incredibly addictive and can result in extreme withdrawals for people who discontinued after prolonged use.

Side Effects Of Spice

Spice is a synthetic drug that is made in illegal labs with no quality control checks. This is why the quality, quantity, and combinations of its ingredients can vary from batch to batch. Variations in quantities or chemical composition changes can result in Spice drug side effects ranging from mild to extremely dangerous. Some samples have even been known to contain rat poison and pesticides.

Short-Term Effects of K2

The extent to which a drug can affect the human body and health depends on several individual factors such as age, genetics, metabolism, and others. The side effects of synthetic marijuana can be observed right from the first use. After short-term use, a range of effects can be seen from mild and treatable to severe and life-long. As the use prolongs, these effects can get worse with time and may even lead to death.

Confused woman due to spice.

Some Other Commonly Observed Spice Side Effects Include:

  • Altered Perception
  • Poor coordination
  • Increased heartbeat
  • Paranoia
  • Hallucination
  • Anxiety
  • Vomiting
  • Hypertension
  • Agitation
  • Sleepiness
  • Irritability
  • Confusion
  • Dizziness
  • Inability to concentrate
  • Stroke
  • Seizures
  • Delusions
  • Psychosis
  • Violent behavior
  • Suicidal tendencies
  • Increased and abnormal breathing
  • Chest pain
  • Heart attack
  • Muscle death
  • Kidney failure

An opinion of a person can dramatically change right after smoking synthetic marijuana. Driving or handling heavy machinery is strictly discouraged for those who are under the influence of this drug.

Long-Term Effects of K2

Since the drug is relatively new on the market, and there is not much information about its effects, scientists have yet to discover the long-term effects of K2. Any chemical consumed by humans comes in contact with muscles and heart via blood and filtered by kidneys. Spice has been known to affect all of these. Health experts link K2 use with heart damage from myocardial ischemia and renal damage. These two are hazardous and clear signs of potential long-term consequences. Some experts also state that long-term use of synthetic marijuana can surge seizure activity in people who are prone to seizures.

Woman feels bad after using spice.

Other prominent signs of long-term Spice use include forgetfulness, confusion, and paralysis. Users report experiencing a complete loss of movement in limbs after using the drug. Even when users quit after long-term use of the drug, they can experience a severe form of anxiety long after quitting. Long-term use can also increase aggressive, irrational, and violent behavior.

Spice Overdose

Like any other drug, it is possible to overdose on synthetic cannabinoids when a user uses too much of it and suffers a dangerous reaction. It can even cause death when synthetic opioids such as fentanyl are present in the mixture. The short-term and long-term K2 side effects are already harmful, but once users overdose on this drug, the effects can be fatal or, if not fatal, can stay with a person for a very long time. People who have experienced spice overdose describe it with words such as horror, terror, and fear.

Symptoms Of Spice Overdose Can Include:

  • Reduction in the heart’s blood supply
  • Seizure
  • Toxic reaction
  • High blood pressure
  • Damage to kidneys

Spice drug side effects are usually not life-threatening, but there have been some instances where people died after overdosing. For example, in July 2014, Connor Reid – a 19-year-old Californian – slipped into a coma and eventually died after overdosing on Spice. Doctors weren’t able to detect K2 in his system, but he still had the package in his pocket, and there was no other drug found in his system.

What makes things complicated is the fact that different manufacturers use different herbs. With unknown ingredients, it’s virtually impossible to detect the metabolites in the blood – and this is the reason doctors could never detect K2 in Connor’s system. The ambiguity of the drug not only makes it hard to detect the drug but can also make it extremely dangerous as a user never knows what they’re smoking or vaping.

Woman fainted due to spice overdose.

New York banned the sale of synthetic drugs in May 2015, and visits to the emergency room due to Spice abuse decreased by 85%. However, before that, residents described that many homeless people who were high on the drug looked like zombies. They had respiratory issues, seemed mentally out of it, paralyzed, staggering, and some would even pass out needing emergency medical care.

Spice Withdrawal Symptoms

In fact, many experts believe that withdrawals from synthetic marijuana are more intense compared to those experienced after smoking natural Cannabis. Individuals who have used K2 for a prolonged period report several issues, including headaches, severe drug cravings, mood swings, suicidal thoughts, psychotic symptoms (paranoia), and hallucinations.

Other Common Withdrawal Symptoms Include:

  • Loss of appetite
  • Dehydration
  • Kidney damage
  • Depression
  • Loss of motivation
  • Extreme sledding
  • Insomnia
  • Chronic diarrhea

Understanding Spice Adverse Reactions

Spice is a name given to a broad range of mixtures of herbs sprayed with a mixture of chemicals to mimic the sensation of smoking Cannabis. It is equally, if not more hazardous than Cannabis. The ingredients of this mixture can vary, making the side effects unpredictable. K2 side effects can range from short-term effects such as euphoria and vomiting to long-term issues such as respiratory problems and hallucinations. In some extreme cases, users may need emergency medical care. And since this is a relatively new drug, the long-term side effects of smoking spice are yet to be revealed. Knowing the information about synthetic cannabinoid adverse reactions can help prevent drug abuse.

People already addicted to the drug can seek help from loved ones and local addiction centers to protect themselves from these side effects. Substance abuse is a very dangerous road with multiple relapses when trying to quit. Still, with determination and help from family, friends, and local addiction centers, it is possible to seek treatment. Although there is no FDA approved drug treatment for synthetic marijuana addiction, treatment can still be sought for symptoms of K2 weed side effects. Doctors can prescribe medication for the management of anxiety and depression associated with the addiction to synthetic cannabinoids. Marijuana addiction treatment protocols can be used for the management of the toxic effects of synthetic marijuana.


Page Sources

  1. K2 /Spice Drug Fact Sheet. Department of Justice. Drug Enforcement Administration. https://www.campusdrugprevention.gov/sites/default/files/K2-Spice_factsheet.pdf
  2. Ziva D. Cooper. Adverse Effects of Synthetic Cannabinoids: Management of Acute Toxicity and Withdrawal. Curr Psychiatry Rep. 2016 May; 18(5): 52. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4923337/
  3. Law R, Schier C, Martin A, Chang A, Wolkin A Centers for Disease Control (CDC) Notes from the field: increase in reported adverse health effects related to synthetic cannabinoid use—United States, January–May 2015. MMWR Morb Mortal Wkly Rep. 2015;64:618–619. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4584925/
  4. K2 /Spice Drug Fact Sheet. Department of Justice. Drug Enforcement Administration. 2020. https://www.dea.gov/sites/default/files/2020-06/K2-spice-2020.pdf
  5. Synthetic Marijuana Can Be Deadly. Department of Behavioral Health. https://dbh.dc.gov/page/synthetic-marijuana-can-be-deadly
  6. Heath TS, Burroughs Z, Thompson AJ, Tecklenburg FW. Acute intoxication caused by a synthetic cannabinoid in two adolescents. The Journal of Pediatric Pharmacology and Therapeutics. 2012;17(2):177-81. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3470439/
  7. Centers for Disease Control and Prevention. Synthetic cannabinoids: An overview for healthcare providers. 2018. https://www.cdc.gov/nceh/hsb/chemicals/sc/healthcare.html
  8. NIDA. Synthetic Cannabinoids (K2/Spice) DrugFacts. National Institute on Drug Abuse. 2018. https://www.drugabuse.gov/publications/drugfacts/synthetic-cannabinoids-k2spice
  9. Greg A. Family shares photos of son's death after taking synthetic marijuana. 2020. https://www.dailymail.co.uk/news/article-2721002/It-poison-Family-share-heartbreaking-photographs-sons-final-moments-hospital-died-taking-ONE-hit-synthetic-marijuana-warn-dangers-drug.html
  10. NYC Health. Health Department Reports Cluster of K2-related Emergency Department Visits, Warns New Yorkers Not to Use This Synthetic Drug. 2018. https://www1.nyc.gov/site/doh/about/press/pr2018/pr040-18.page

Published on: June 9th, 2017

Updated on: January 6th, 2021

About Author

Isaak Stotts, LP

Isaak Stotts is an in-house medical writer in AddictionResource. Isaak learned addiction psychology at Aspen University and got a Master's Degree in Arts in Psychology and Addiction Counseling. After graduation, he became a substance abuse counselor, providing individual, group, and family counseling for those who strive to achieve and maintain sobriety and recovery goals.

Medically Reviewed by

Tania Kelly

Tania Kelly, author of Keep Calm and Treat Addiction is a credentialed Mental Health Nurse and Tobacco Treatment Specialist, passionate about addiction recovery. As a senior clinician, Tania constantly shares the concepts outlined in her book with health service providers, aiming to demystify addiction treatment and equip others in evidence-based practice.