Drug & supplement interaction

K2/spice + Ziprasidone

Ziprasidone brand name: Geodon.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

K2/spice has a moderate interaction with Ziprasidone. Theoretically, K2/spice might have an additive effect with drugs that prolong the QT interval and increase the risk of ventricular arrhythmias.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

K2/spice and Ziprasidone

Here is the interaction we found between these two, with the evidence behind it.

Moderate

QT INTERVAL-PROLONGING DRUGS

Why this applies to Ziprasidone

Ziprasidone falls under QT INTERVAL-PROLONGING DRUGS — the group K2/spice interacts with.

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.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

First things first: K2/Spice isn't an herb or a safe supplement. It's plant material sprayed with man-made cannabinoid chemicals, and it's been linked to seizures, psychosis, and deaths. I would steer clear of it entirely, no matter what else you take.

Here's the specific worry with ziprasidone (Geodon). This medicine is already one of the antipsychotics most known for stretching out the heart's electrical recovery time, called the QT interval. K2/Spice has been tied to QT changes too. Put them together and the effects may stack, which can raise the risk of a dangerous, irregular heartbeat. This is based on case reports and is theoretical, not proven, but with ziprasidone's known heart risk I take it seriously. Please talk with your doctor or pharmacist before making any changes.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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
  2. 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.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

K2/spice Also Interacts With Other Medications

K2/spice has 207 moderate known drug interactions in our database — the Ziprasidone one above is one of them. If you take anything else, check it against the full list below.

Moderate 207 No known interaction 2,623 (incl. Ziprasidone)
Taking anything else?

Check Another of Your Medications Against K2/spice

Covers the 2,830 medications we’ve checked against K2/spice. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Ziprasidone

This page covers K2/spice only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ziprasidone page lists 188 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 11 major · 136 moderate · 41 minor.

From our pharmacist’s overview on the Ziprasidone page

“Ziprasidone (Geodon) is an antipsychotic that already carries a warning about disturbing the heart's electrical rhythm, so a list with 11 major-rated interactions calls for real care before mixing in supplements. Most of the 188 ingredients on file touch the liver enzyme, CYP3A4, that clears ziprasidone from the body.”

Reviewed by 2 · Jul 18, 2026

Open the Ziprasidone interaction page

How much people look this up

Where K2/spice and Ziprasidone Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement K2/spice
Steady interest

#912 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Ziprasidone
Top half

#1,063 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About K2/spice

What is K2/spice?

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

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.

Read the full K2/spice monograph & all interactions
Medication

About Ziprasidone

What Is Ziprasidone Used For?

Brand name: Geodon

Ziprasidone is prescribed for adults with schizophrenia and for adults experiencing manic or mixed episodes of bipolar I disorder. It can be used on its own for acute manic or mixed episodes, or added to lithium or valproate to help maintain stability in bipolar I disorder long-term.

An injectable form is also available for rapid control of agitation in people with schizophrenia who need quick relief. Prescribers are advised to weigh ziprasidone's potential effect on heart rhythm when choosing among treatment options.

See full Ziprasidone drug information
Keep checking

Other Drugs & K2/spice

Browse every other medication we’ve checked against K2/spice — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
207Moderate
0Minor
2,622No known interaction
207 Moderate 2,622 No interaction
Moderate

207 interactions

Showing 60 of 207 moderate interactions — see all 207 on the K2/spice page.

No interaction 2,622 drugs checked — show the list

We also checked K2/spice against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,622 medications checked with no known interaction — see the full K2/spice list.

See the full K2/spice interactions page
See every supplement checked against Ziprasidone, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

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.

© 2021 Therapeutic Research Center, LLC

Keep exploring
K2/spice monograph › Uses, safety, and every drug interaction in one place Ziprasidone supplement interactions › Every supplement checked against Ziprasidone, ranked by severity Ziprasidone drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking K2/spice and Ziprasidone Together: Common Questions

Can you take K2/spice with Ziprasidone?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the K2/spice and Ziprasidone interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Ziprasidone and K2/spice?

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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.