Supplements and Clozapine.
Clozapine, sold under the brand names Clozaril, Denzapine, Zaponex, is an antipsychotic: it antagonises dopamine D2 receptors and (for atypicals) serotonin receptors.
Clozapine is an antipsychotic medicine. The class divides into typicals (haloperidol, chlorpromazine, older agents) and atypicals (olanzapine, quetiapine, risperidone, aripiprazole, the newer agents). Both block dopamine D2 receptors. The atypicals add 5-HT2 receptor blockade and a different side effect profile. Most UK community prescribing is atypicals. The supplement surface includes three patterns: additive sedation (especially with quetiapine), QT prolongation (haloperidol, ziprasidone, some others), and CYP interactions for the more 3A4-sensitive agents in the class. Metabolic side effects (weight gain, glucose dysregulation, lipid effects) underpin the routine monitoring that NICE NG178 recommends. St John's Wort is flagged by the BNF across the class given enzyme induction concerns. Specific supplements with the closest serotonergic overlap (5-HTP, SAMe at high dose, saffron extract) warrant care, particularly alongside atypicals with significant 5-HT2 activity.
Below are the 1 documented pair we have explicitly assessed against Clozapine in the Distil database: 1 amber. The pairs cluster around 1 mechanism: Reduced antipsychotic effect. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Reduced antipsychotic effect
High-dose glycine taken alongside clozapine may work against the clozapine, making it less effective at controlling psychotic symptoms. This was seen in studies using very large glycine doses (30 to 60 grams a day), far above a typical glycine supplement. If you take clozapine, it is best not to add high-dose glycine, and to discuss any glycine supplement with the team that manages your medication, because clozapine is closely monitored.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologyWant this reasoning across everything you take?
This page checks the pairs you enter. A personalised Distil report applies the same graded, cited reasoning to your whole stack: your goals, conditions, medications, diet, and the compounds worth adding or dropping. The interactions check is one section of it. You can read a real one in full before you decide.
See a real sample reportSomething missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.