Supplements and Citalopram.
Citalopram, sold under the brand names Cipramil, Celexa, is a selective serotonin reuptake inhibitor (SSRI): it raises synaptic serotonin by blocking its reuptake.
Citalopram is the second most prescribed SSRI in England after sertraline, used for depression and anxiety. Mechanism mirrors sertraline (serotonin transporter inhibition) but the metabolic profile differs. Citalopram is metabolised by CYP2C19, CYP3A4, and CYP2D6, which makes it more sensitive to PPI co-prescription. Omeprazole raises citalopram exposure modestly. The MHRA dose cap is the operative point. 40mg maximum in adults under 65. 20mg in adults over 65 or with hepatic impairment. The cap exists because QT prolongation rises with dose. That QT signal matters when citalopram stacks with anything else extending QT: certain antibiotics (clarithromycin, levofloxacin), some antiemetics, and a small number of supplements. Serotonergic interactions are the same as sertraline (St John's Wort, 5-HTP, tryptophan, rhodiola, saffron extract). Escitalopram, the S-enantiomer, sits in a similar class but with a separate dose schedule.
Below are the 7 documented pairs we have explicitly assessed against Citalopram in the Distil database: 2 red and 5 amber. The pairs cluster around 1 mechanism: Additive serotonergic activity. 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
Last reviewed 21 June 2026. Each interaction below is assessed against PubMed-indexed evidence.
Additive serotonergic activity
Red Does 5-HTP interact with ?
5-HTP is the precursor your body uses to make serotonin. Combined with an SSRI like citalopram, it can cause serotonin syndrome. Do not combine.
Evidence: Supported by human study data.
Red Does St John's Wort interact with ?
St John's Wort and citalopram both raise serotonin levels. Combined, they can cause serotonin syndrome. Do not combine.
Evidence: Supported by human study data.
Amber Does Ashwagandha interact with ?
Ashwagandha has mild effects on serotonin pathways that overlap with citalopram. Most people tolerate the combination but watch for restlessness, jaw tension, or sleep disruption.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does L-Tryptophan interact with ?
Tryptophan is the building block your body uses to make serotonin, so adding it to citalopram raises serotonin from both directions. The combination can cause agitation, sweating, tremor, shivering, muscle twitching, or a racing heart. Do not stack them without your GP's involvement.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Rhodiola Rosea interact with ?
Rhodiola has mild effects on serotonin pathways that can add to citalopram's. Most people tolerate the combination, but watch for restlessness, sweating, tremor, or a racing heart, and talk to your GP before stacking them, especially if your dose has recently changed.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does SAMe interact with ?
SAMe has its own antidepressant, serotonin-related activity, which may add to citalopram's. Most people tolerate the combination, but watch for restlessness, sweating, tremor, shivering, or a racing heart, and tell your GP before stacking them, especially if your citalopram dose has recently changed.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Saffron Extract interact with ?
Saffron extract has its own antidepressant effect, possibly via serotonin-receptor modulation. Combined with citalopram, the serotonergic effect may stack. Watch for restlessness, sweating, or muscle twitching, and tell your GP if you start saffron while on citalopram.
Evidence: Limited human data, based on case reports and a known mechanism.
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.
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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 checked across everything you take?
This page checks the pairs you enter. The personalised Distil report goes further:
- the same graded, cited interaction check across your whole stack, not just the pairs you thought to type in
- where your current routine may be leaving you short of your goals
- the evidence-graded compounds worth adding, and the ones worth dropping
It's a paid report: £79, or £49 founder pricing while we earn our first reviews. The interactions check is one section of it, and 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.