Medication·Interactions·Reviewed June 9, 2026
Olanzapine interactions.
Olanzapine has 4 documented interactions in the NutriStack database, including 2 flagged to avoid or as a serious conflict. The full interaction list is below. None of this is a substitute for your prescriber's advice.
Olanzapine at a glance.
A quick, data-grounded summary. The full tables are below.
Olanzapine has 4 documented interactions in the NutriStack database, including 2 flagged to avoid or as a serious conflict. The full interaction list is below. None of this is a substitute for your prescriber's advice.
Substances that interact with olanzapine.
Every supplement and medication in the NutriStack database with a documented interaction with this drug, highest-severity first. Open any pair for the mechanism and sources.
| Substance | Interaction | What happens |
|---|---|---|
| Cannabis (THC-Dominant) | Conflict | THC-dominant cannabis can undermine olanzapine treatment by increasing relapse risk and worsening psychosis outcomes. Systematic reviews link... details → |
| St. John's Wort | Conflict | St. John's Wort induces CYP1A2, the primary metabolic pathway for olanzapine. This can reduce olanzapine levels, causing psychotic relapse. |
| Alcohol | Caution | Alcohol can add to olanzapine-related sedation, slowed reaction time, dizziness, and impaired coordination. Olanzapine can already cause sleepiness... details → |
| Melatonin | Synergy | Melatonin has been studied as an adjunct to reduce some metabolic side effects of olanzapine, including weight and cardiometabolic changes.... details → |
The full olanzapine profile.
Uses, typical dosing, side effects, and the cited evidence for this medication.
Common olanzapine questions.
Quick answers drawn from the tables above.
What interacts with Olanzapine?
In the NutriStack database, Olanzapine has 4 documented interactions. The most notable include Cannabis (THC-Dominant), St. John's Wort, Alcohol, and Melatonin. Check any specific combination before taking it and confirm with your prescriber.
Which substances should I avoid with Olanzapine?
Olanzapine is flagged against 2 substances in the database, including Cannabis (THC-Dominant) and St. John's Wort. These pairings carry a higher risk and should be reviewed with a clinician before combining.
Is it safe to take Cannabis (THC-Dominant) with Olanzapine?
NutriStack classifies the Cannabis (THC-Dominant) and Olanzapine pairing as conflict: THC-dominant cannabis can undermine olanzapine treatment by increasing relapse risk and worsening psychosis outcomes. Systematic reviews link continued cannabis use in... Avoid THC-dominant cannabis while taking olanzapine for psychosis or mood stabilization. If cannabis use continues, your prescriber should know so... Always confirm with your prescriber.
Check your whole stack
See how olanzapine fits your supplements.
NutriStack screens your full routine for interactions and depletions, and updates the moment you change it.