Herb & supplement monograph

K2/spice Drug Interactions, Uses, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how K2/spice interacts with medications. The heart of this page is the interaction list — every drug K2/spice is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what K2/spice is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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K2/spice Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, K2/spice drug interactions carry a real, moderate level of risk for most people, and it matters that K2/spice is a synthetic drug rather than a true herb or supplement. None of the listed interactions are rated major or minor; every one of the large number on record is rated moderate.

Interactions deserving the most attention

The combinations that concern us most involve QT interval-prolonging drugs, because numerous cases of abnormal heart rhythm measurements have been reported in people using K2/spice, and adding another medicine with the same effect could raise the risk of dangerous heart rhythms. Anticonvulsants also stand out, since K2/spice might strengthen or weaken seizure control, and seizures themselves have been reported after inhaling it. For anyone whose heart rhythm or seizure control is closely managed, this combination could matter.

What the rest of the list means

The long list of moderate interactions does not mean every combination has been proven harmful in people. Much of the evidence is theoretical or comes from animal research and limited case reports rather than well-controlled human studies. Still, because K2/spice products vary widely in what they contain, their effects on medications are hard to predict.

Check your medications against K2/spice

Based on HelloPharmacist’s K2/spice interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with K2/spice

208 medications have a known interaction with K2/spice, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against K2/spice using our pharmacist-reviewed interaction data.

AI summaries are generated from our K2/spice interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact K2/spice combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs K2/spice affects

Every type of medication (drug category) K2/spice is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 2 drug categories K2/spice interacts with

AnticonvulsantsQt Interval-prolonging Drugs

Anticonvulsants

Theoretically, K2/spice might increase or decrease the effectiveness of anticonvulsant drugs.
Some animal research suggests that certain types of synthetic cannabinoids found in some K2/spice products can potentiate the effects of anticonvulsants. However, seizures have also been reported with inhalation of K2/spice.

Likelihood Possible Evidence D

Qt Interval-Prolonging Drugs

Theoretically, K2/spice might have an additive effect with drugs that prolong the QT interval and increase the risk of ventricular arrhythmias.
There have been numerous cases of increased QT and corrected QT intervals in patients using K2/spice.

Likelihood Possible Evidence D

Monograph

K2/spice: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

K2/Spice is NOT a herbal supplement — it is plant material sprayed with man-made synthetic cannabinoid chemicals. It is dangerous, unpredictable, and has caused seizures, heart problems, psychosis, and deaths, so it should not be used.

Part used: Not a plant part; synthetic chemicals sprayed onto dried plant material
Common forms: Dried plant material that is smoked or vaped; sometimes sold as liquid for vaping

People commonly use it for

Recreational drug ('legal high')
Marijuana substitute
Mood or perception changes
Sometimes used to avoid drug testing

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallBest avoided

These products are illegal, unregulated, and have caused serious harm and death.

PregnancyInsufficient reliable information

K2/spice is UNSAFE when used during pregnancy and lactation. While the adverse effects of K2/spice have not been adequately described in pregnant or n...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

K2/spice is UNSAFE when used during pregnancy and lactation. While the adverse effects of K2/spice have not been adequately described in pregnant or n...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

K2 and Spice are not real herbs or dietary supplements. They are brand-style names for products often called "synthetic marijuana," "fake weed," or "synthetic cannabinoids." These products are made by spraying man-made chemicals onto dried, shredded plant material so they look like dried herbs or marijuana. They are usually smoked, but some versions are made into liquids for vaping.

The dried plant base itself is not the active part. The dangerous part is the lab-made chemical mixture sprayed on top. These chemicals are designed to act on the same brain receptors as THC, the main mind-altering compound in cannabis, but they are often far stronger and much more unpredictable.

K2/Spice is often sold in shiny foil packets labeled "not for human consumption," "herbal incense," or "potpourri" to get around laws. Despite these labels, people use them to get high. Many of the chemicals involved are illegal, and manufacturers frequently change the recipe to dodge laws.

Uses & effectiveness

People use K2/Spice mainly as a recreational drug to feel high, often as a cheaper or supposedly "legal" substitute for marijuana. Some people use it hoping to pass a standard drug test, since older tests may not detect these chemicals.

There is no proven medical or health benefit to K2/Spice. It is not approved or recommended for any health condition. Unlike some plant supplements, it has no traditional or evidence-based therapeutic use. The only well-documented effects are harmful ones.

Because the recipe changes often and products are not tested for quality, users have no way to know what chemical or dose they are actually taking. This makes every use a gamble.

How it works

The synthetic cannabinoid chemicals in K2/Spice attach to cannabinoid receptors in the brain and body — the same receptors that THC affects. However, many of these synthetic chemicals bind to those receptors much more strongly and completely than THC does.

This stronger, fuller activation is thought to be one reason these products cause more severe and dangerous effects than marijuana. The exact chemicals vary from batch to batch, and many have never been tested in humans, so their full effects are not understood.

Some batches have also been found contaminated with other dangerous substances, including chemicals that cause severe bleeding. This adds another layer of unpredictable risk.

Safety & precautions

K2/Spice is not safe, and there is no safe amount. These products have caused emergency room visits, hospitalizations, and deaths across many age groups. Because the contents are unknown and constantly changing, even someone who used a product before with no problem can have a severe reaction the next time.

Teenagers and young adults are common users and are at serious risk. People with heart conditions, mental health conditions, or seizure disorders may be especially vulnerable to severe harm.

Pregnancy and breastfeeding: Do not use K2/Spice if you are pregnant or could become pregnant. These chemicals can harm a developing baby. Likewise, avoid completely while breastfeeding, since the chemicals may pass to the infant.

If you or someone you know uses these products, please talk with a doctor or pharmacist. Help is available, and in the U.S. you can call the Poison Help line at 1-800-222-1222 for emergencies or guidance.

Side effects

Reported effects from K2/Spice can be severe and include:

Fast or irregular heartbeat and chest pain
Very high blood pressure
Severe anxiety, agitation, confusion, or paranoia
Hallucinations and psychosis
Vomiting
Seizures
Kidney damage
Loss of consciousness

Serious and life-threatening reactions have occurred, including strokes, heart attacks, severe bleeding (from contaminated batches), and death. Some users develop dependence and have withdrawal symptoms when they stop.

If someone shows severe symptoms after using K2/Spice — such as chest pain, seizures, trouble breathing, or unconsciousness — call 911 or local emergency services right away.

K2/spice: Reported Adverse Effects

Documented safety reports on K2/spice from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

When inhaled, K2/spice is unsafe and can cause many serious adverse effects.

Most Common Adverse Effects:

Inhaled: Agitation, anxiety, ataxia, diarrhea, dry mouth, hallucinations, hypertension or hypotension, lethargy, nausea, paranoia, tachycardia, vomiting.

Serious Adverse Effects (Rare):

Inhaled: Acute kidney injury, acute respiratory distress syndrome, aggression, agitation, arrhythmia, bradycardia, cardiac arrest, catatonia, cerebral ischemia, coma, delirium, death, hallucinations, hematologic abnormalities, hyperglycemia, liver failure, myocardial infarction, panic attacks, psychosis, respiratory failure, rhabdomyolysis, seizures, suicidality.

Reports by condition

Acute kidney injury (AKI) Renal

When inhaled, K2/spice can cause acute kidney injury. More than 50 cases requiring hospitalization have been reported in patients who smoked K2/spice.

Acute respiratory distress syndrome (ARDS) Pulmonary/Respiratory

When inhaled, K2/spice has been associated with dyspnea, dysregulated breathing, pulmonary infiltrates, respiratory failure, pneumothorax, and acute respiratory distress syndrome. Long-term use of K2/spice has been associated with chronic cough.

In one case series, 21 of 30 patients requiring critical care for K2/spice use also required mechanical ventilation. In an observational study of 29 patients admitted to emergency departments with confirmed K2/spice overdose, 25% developed acute respiratory failure, although some patients had also been exposed to opioids or sedatives. Additionally, subcutaneous emphysema, pneumothorax, pneumomediastinum, and pneumoperitoneum have been reported 6 days after ingesting K2/spice in one case.

Anxiety Neurologic/CNS

When inhaled, K2/spice can cause drowsiness, lethargy, vertigo, ataxia, hyperreflexia, nystagmus, confusion, anxiety, cognitive impairment, emotional dysregulation, seizures, and coma. Numerous cases of seizures secondary to K2/spice use have been reported. Between 4% to 15% of poison control center consults or emergency department visits for K2/spice toxicity involved generalized tonic-clonic seizures, including some cases of status epilepticus. A cannabidiol supplement contaminated with the synthetic cannabinoid AB-FUBINACA caused seizures, delirium, agitation, and tachycardia in an 8-year-old male with epilepsy.

Coma has been reported, mostly in males using K2/spice alone or concomitantly with alcohol, methadone, or unidentified opiates. Chronic use has been associated with cases of encephalopathy, specifically posterior reversible encephalopathy syndrome (PRES) and toxic leukoencephalopathy with hyperreflexia, paratonia (inability to relax muscles), and cogwheel rigidity. In healthy, cannabis-experienced users, inhaling 75-125 mcg/kg of the synthetic cannabinoid JWH-018 impaired motor coordination, attention, and memory, slowed response speeds, and lowered speed-accuracy efficiency.

Anxiety Psychiatric

When inhaled, K2/spice can cause agitation, psychosis, delirium, hallucinations, paranoia, anxiety, confusion, altered mental status, panic attacks, aggressive behaviors, and suicidality. Agitation, which escalates to delirium and psychosis, appears to be the most common acute psychiatric adverse effect reported after K2/spice use, occurring in up to 41% of toxicity cases. Anxiety, depression, and hallucinations also appear to be relatively common. These adverse psychiatric effects might contribute to cases of self-harm and suicide after K2/spice use. Data from over 29,000 adolescents in the Youth Risk Behavior Surveillance System shows that mental health issues associated with the use of K2/spice include paranoia, psychosis, hallucinations, irritability, dissociation, anxiety, catatonia, violence, and self-harm. In a subgroup who had used K2/spice once or twice, 18% attempted suicide, while in the subgroup that had used K2/spice three or more times, 30% attempted suicide. The association between suicide attempts and K2/spice use was strongest in Black and LGBTQ populations.

Regular use of K2/spice over 6-18 months has been associated with withdrawal symptoms including craving, anxiety, insomnia, and hallucinations lasting about 5-9 days. Long-term use of K2/spice for 5-24 months has resulted in psychoses, primarily with hallucinations, delusions, and paranoia lasting for 10-14 days, and sometimes as long as 6 weeks. Psychosis gradually subsides to symptoms of anxiety, depression, and cognitive dysfunction, which last 4-8 weeks.

Arrhythmia Cardiovascular

When inhaled, K2/spice can cause serious adverse cardiovascular effects, including tachycardia or bradycardia, hypertension or hypotension, coronary vasospasm, acute coronary syndrome, congestive heart failure, ventricular fibrillation, QT prolongation, myocardial ischemia/infarction, stroke, cardiac arrest, cardiomyopathy, and sudden cardiac death. Data from poison control centers and medical toxicology databases suggest that tachycardia occurs in up to 75% of K2/spice toxicity cases. While less common, myocardial ischemia/infarction, stroke, resistant ventricular fibrillation, cardiogenic shock, and sudden cardiac death have also been reported after K2/spice use.

The most common arrhythmias associated with K2/spice are supraventricular, including sinus tachycardia, atrial fibrillation, sinus bradycardia, and supraventricular tachycardia. Ventricular arrhythmias can also occur, including left bundle branch block, QT prolongation, AV block, and ventricular fibrillation. In one case series, 10 of 30 patients requiring critical care for K2/spice use experienced QT prolongation. In another case series, adults that used K2/spice had a higher corrected QT interval (434.5 ms) when compared with non-users (411 ms).

Diarrhea Gastrointestinal

When inhaled, K2/spice can cause nausea, vomiting, abdominal pain, and diarrhea. In a review of United States poison control center reports, vomiting occurred in around 16% of K2/spice toxicity cases. An analysis of online forum posts from K2/spice users suggests that around 5% of users experience nausea and/or vomiting. In a review of patients experiencing acute kidney injury associated with K2/spice use, the rates of abdominal pain, nausea, and vomiting were 56%, 58%, and 60%, respectively. Cannabinoid hyperemesis syndrome (CHS), a condition characterized by severe and repetitive episodes of nausea and vomiting, has also been reported with K2/spice use.

Fatigue Hepatic

When inhaled, K2/spice has been associated with hepatitis. In one case, a 45-year-old male presenting with somnolence, lethargy, and fatigue after smoking 2 grams of K2/spice daily for one week was found to have evidence of hepatocellular necrosis and worsening liver failure. The patient was treated with N-acetylcysteine and made a full recovery. In another case, a 26-year-old healthy female who used K2/spice presented to the emergency room with worsening liver failure likely due to acute hepatocellular necrosis and ultimately required a liver transplant.

Muscle breakdown Musculoskeletal

When inhaled, K2/spice has been associated with rhabdomyolysis. In one case series, 8 of 30 patients requiring critical care for K2/spice use experienced rhabdomyolysis. Also, a 23-year-old male who smoked K2/spice daily for two weeks presented to the emergency department with psychosis, severe agitation, and highly elevated creatine phosphokinase (CPK) levels. After psychiatric care and intravenous fluids, the patient's CPK levels and other symptoms returned to normal within 15 days. While researchers were unable to rule out other mechanisms of K2/spice-induced rhabdomyolysis, they suggested that this case was secondary to psychomotor agitation from K2/spice-induced psychosis.

Thrombocytopenia Immunologic

When inhaled long-term, K2/spice has been associated with immune thrombocytopenia. In one case, a 23-year-old male with a one-year history of K2/spice abuse presented with epistaxis and petechial rashes on both legs. Laboratory testing confirmed a diagnosis of immune thrombocytopenia, and the patient was successfully treated with prednisolone.

Öztürk E, Oral A, Özdemir M, Bambul N. Synthetic marijuana "K2" induced ITP. Platelets 2015;26(3):258-9.

Thrombocytopenia Hematologic

When inhaled, K2/spice has been linked to hematologic complications. An outbreak of synthetic cannabinoid-associated coagulopathy was reported in Illinois in 2018. Anticoagulant testing in 15 patients with suspected synthetic cannabinoid-associated coagulopathy suggested that K2/spice contaminated with brodifacoum, a 4-hydroxycoumarin derivative was to blame. One death due to synthetic cannabinoid-associated coagulopathy was reported during this outbreak. In one case, a 65-year-old male presented with hematochezia, hematuria, and hemoptysis after using K2/spice contaminated with brodifacoum and another 4-hydroxycoumarin, difenacoum. The patient required high-dose vitamin K treatment for 6 weeks and tapering doses over 6 months.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no safe or recommended dose of K2/Spice. Because these are unregulated, illegal products with unknown and constantly changing ingredients, no dose can be considered safe. The strength can vary wildly even within a single package.

This is not a supplement that should be taken at any amount. If you are looking for help with substance use, please reach out to a healthcare provider, pharmacist, or a substance-use support service.

Pregnancy & Breastfeeding

K2/spice & Pregnancy

Insufficient reliable information

K2/spice is UNSAFE when used during pregnancy and lactation. While the adverse effects of K2/spice have not been adequately described in pregnant or nursing women, reports of serious and sometimes fatal adverse effects in K2/spice users suggests that K2/spice would also be harmful to pregnant or nursing women. Endogenous cannabinoid signaling is involved in numerous stages of pregnancy, including embryo development, transport, and implantation. Because K2/spice can interfere with cannabinoid signaling, it could theoretically compromise fertility and pregnancy outcomes.

K2/spice & Breastfeeding

Insufficient reliable information

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 40 references that drive our K2/spice monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Amar JY, Ruta J, Rahimian D, Dillinger RL, Katz P. Toxic leukoencephalopathy with extrapyramidal dysfunction due to synthetic cannabinoids. J Clin Neurosci 2018;58:213-4. PubMed
Andonian DO, Seaman SR, Josephson EB. Profound hypotension and bradycardia in the setting of synthetic cannabinoid intoxication - a case series. Am J Emerg Med 2017;35(6):940.e5-940.e6. PubMed
McIlroy G, Ford L, Khan JM. Acute myocardial infarction, associated with the use of a synthetic adamantyl-cannabinoid: a case report. BMC Pharmacol Toxicol 2016;17:2. PubMed
Chinnadurai T, Shrestha S, Ayinla R. A curious case of inhalation fever caused by synthetic cannabinoid. Am J Case Rep 2016;17:379-83. PubMed
Clark BC, Georgekutty J, Berul CI. Myocardial ischemia secondary to synthetic cannabinoid (K2) use in pediatric patients. J Pediatr 2015;167(3):757-61.e1. PubMed
Davidson C, Opacka-Juffry J, Arevalo-Martin A, Garcia-Ovejero D, Molina-Holgado E, Molina-Holgado F. Spicing up pharmacology: a review of synthetic cannabinoids from structure to adverse events. Adv Pharmacol 2017;80:135-68. PubMed
Durand D, Delgado LL, de la Parra-Pellot DM, Nichols-Vinueza D. Psychosis and severe rhabdomyolysis associated with synthetic cannabinoid use: a case report. Clin Schizophr Relat Psychoses 2015;8(4):205-8. DOI
Freeman MJ, Rose DZ, Myers MA, Gooch CL, Bozeman AC, Burgin WS. Ischemic stroke after use of the synthetic marijuana "spice". Neurology 2013;81(24):2090-3. PubMed
Kelkar AH, Smith NA, Martial A, Moole H, Tarantino MD, Roberts JC. An outbreak of synthetic cannabinoid-associated coagulopathy in Illinois. N Engl J Med 2018;379(13):1216-23. PubMed
Lamy FR, Daniulaityte R, Nahhas RW, et al. Increases in synthetic cannabinoids-related harms: results from a longitudinal web-based content analysis. Int J Drug Policy. 2017;44:121-9. PubMed
Law R, Schier J, Martin C, 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(22
Castaneto MS, Gorelick DA, Desrosiers NA, Hartman RL, Pirard S, Huestis MA. Synthetic cannabinoids: epidemiology, pharmacodynamics, and clinical implications. Drug Alcohol Depend 2014;144:12-41. PubMed
Monte AA, Calello DP, Gerona RR, et al. Characteristics and treatment of patients with clinical illness due to synthetic cannabinoid inhalation reported by medical toxicologists: a ToxIC database study. J Med Toxicol 2017;13(2):146-52. PubMed
Öztürk E, Oral A, Özdemir M, Bambul N. Synthetic marijuana "K2" induced ITP. Platelets 2015;26(3):258-9. PubMed
Schwartz MD, Trecki J, Edison LA, Steck AR, Arnold JK, Gerona RR. A common source outbreak of severe delirium associated with exposure to the novel synthetic cannabinoid ADB-PINACA. J Emerg Med 2015;48(5):573-80. PubMed
Sheikh IA, Luksic M, Ferstenberg R, Culpepper-Morgan JA. Spice/K2 synthetic marijuana-induced toxic hepatitis treated with N-acetylcysteine. Am J Case Rep 2014;15:584-8. PubMed
Tait RJ, Caldicott D, Mountain D, Hill SL, Lenton S. A systematic review of adverse events arising from the use of synthetic cannabinoids and their associated treatment. Clin Toxicol (Phila) 2016;54(1):1-13. PubMed
Yamanoglu A, Celebi Yamanoglu NG, Evran T, Sogut O. How much can synthetic cannabinoid damage the heart? A case of cardiogenic shock following resistant ventricular fibrillation after synthetic cannabinoid use. J Clin Ultrasound 2018;46(9):605-9. PubMed
Zheng CY, Minniti CP, Chaitowitz MH. Sickle cell crisis complicated by synthetic cannabinoid abuse: a case report. Hemoglobin 2016;40(3):220-2. PubMed
Yamanoglu A, Cakmak S, Celebi Yamanoglu NG, Sogut O. A new side effect of synthetic cannabinoid use by the bucket (waterpipe) method: acute respiratory distress syndrome (ARDS). Turk J Emerg Med 2017;18(1):42-4. PubMed
Tse R, Kodur S, Squires B, Collins N. Sudden cardiac death complicating acute myocardial infarction following synthetic cannabinoid use. Intern Med J 2014;44(9):934-6. PubMed
Rianprakaisang T, Gerona R, Hendrickson RG. Commercial cannabidiol oil contaminated with the synthetic cannabinoid AB-FUBINACA given to a pediatric patient. Clin Toxicol (Phila). 2020;58(3):215-216. PubMed
Kourouni I, Mourad B, Khouli H, Shapiro JM, Mathew JP. Critical Illness Secondary to Synthetic Cannabinoid Ingestion. JAMA Netw Open. 2020;3(7):e208516. PubMed
Ahmed ST, Alam A, Hassan A, Kamal S, Mahmood M. Acute Liver Failure Caused by Synthetic Marijuana Use. Am J Ther. 2020. doi: 10.1097/MJT.0000000000001181. PubMed
Ahmed T, Khan A, See VY, Robinson S. Cardiac arrest associated with synthetic cannabinoid use and acquired prolonged QTc interval: A case report and review of literature. HeartRhythm Case Rep. 2020;6(5):283-286. PubMed
Cohen K, Mama Y, Rosca P, Pinhasov A, Weinstein A. Chronic Use of Synthetic Cannabinoids Is Associated With Impairment in Working Memory and Mental Flexibility. Front Psychiatry. 2020;11:602. PubMed
Godwin PO, Unterman S, Elfessi ZZ, Bhagat JD, Kolman K. Management of Rodenticide Poisoning Associated with Synthetic Cannabinoids. Fed Pract. 2019;36(5):237-241.
Parajuli P, Regmi MR, Lara-Garcia OE, Abu Limon I, Deckard A. Man vs. man-made marijuana: A case of drug-induced posterior reversible encephalopathy syndrome (PRES) due to K2, a synthetic cannabinoid (SCB). J Community Hosp Intern Med Perspect. 2020;10(4) DOI
Skryabin VY, Vinnikova MA. Psychotic Disorders in Patients Who Use Synthetic Cannabinoids. J Psychiatr Pract. 2019 Nov;25(6):485-490. PubMed
Yildiz SS, Sutasir MN, Sigirci S, et al. Acute effects of synthetic cannabinoids on ventricular repolarization parameters. Turk Kardiyol Dern Ars. 2019;47(5):384-390.
Martínez L, La Maida N, Papaseit E, et al. Acute pharmacological effects and oral fluid concentrations of the synthetic cannabinoids JWH-122 and JWH-210 in humans after self-administration: an observational study. Front Pharmacol. 2021 Aug 19;12:705643. PubMed
Simon G, Tóth D, Heckmann V, Kuzma M, Mayer M. Lethal case of myocardial ischemia following overdose of the synthetic cannabinoid ADB-FUBINACA. Leg Med (Tokyo). 2022 Feb;54:102004. PubMed
Stogner J, Patterson C. Suicidal ideation, planning, and attempts among synthetic cannabinoid users across different demographic subgroups. Crisis. 2022;43(4):323-330. PubMed
Manini AF, Krotulski AJ, Schimmel J, et al. Respiratory failure in confirmed synthetic cannabinoid overdose. Clin Toxicol (Phila). 2022;60(4):524-526. PubMed
Theunissen EL, Reckweg JT, Hutten NRPW, et al. Intoxication by a synthetic cannabinoid (JWH-018) causes cognitive and psychomotor impairment in recreational cannabis users. Pharmacol Biochem Behav. 2021 Mar;202:173118. PubMed
Ruiz-Maldonado TM, Dorey A, Christensen ED, Campbell KA. Near-fatal spice intoxication of a toddler. Pediatrics. 2021 Aug;148(2):e2021050888. PubMed
D'Errico S, Zanon M, Radaelli D, et al. Acute Kidney Injury (AKI) in Young Synthetic Cannabinoids Abusers. Biomedicines 2022;10(8):1936. PubMed
Fatmi SS, Outlaw A. Coronary Vasospasm Associated With Synthetic Marijuana Resulting in Transient Electrocardiogram Changes and Troponin Elevation. Cureus 2022;14(5):e25084. PubMed
Gala Z, Kravchenko T, Volk L, Chatani P, Kar R, Choron RL. Subcutaneous Emphysema, Pneumothorax, Pneumomediastinum, and Pneumoperitoneum Following Synthetic Cannabinoid Toxicity in an Incarcerated Man. Am Surg 2022. PubMed
Jafry AH, LaGrow A, Akhtar KH, et al. Synthetic cannabinoids and ST elevation myocardial infarction. Am J Med Sci 2022;364(4):481-491. PubMed

Keep reading

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

Pharmacist Counseling Corner

K2/spice: Common Questions

Does K2/spice interact with prescription medications?

Yes. We list 208 medications with a known interaction with K2/spice. Use the checker above to see how K2/spice interacts with a specific drug.

How are K2/spice interactions rated?

Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.

Is it safe to take K2/spice with my medications?

It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.

Where does this K2/spice interaction information come from?

Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.

Is K2/spice a natural herbal product?

No. Although it looks like dried herbs, the plant material is just a carrier sprayed with man-made (synthetic) chemicals. It is not a natural or herbal supplement.

Is K2/spice safer than marijuana?

No. It is often far more dangerous and unpredictable than marijuana, and has caused seizures, heart problems, psychosis, and deaths.

Is K2/spice legal?

Many of the chemicals used are illegal, and laws ban these products in many places. Sellers often change the recipe or labeling to get around the law, but that does not make them safe.

What should I do if someone reacts badly to K2/spice?

Call emergency services (911 in the U.S.) for severe symptoms like chest pain, seizures, or unconsciousness, or call Poison Help at 1-800-222-1222 for guidance.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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