Supplements and Paroxetine hydrochloride.
Paroxetine hydrochloride, sold under the brand name Seroxat, is a selective serotonin reuptake inhibitor (SSRI): it raises synaptic serotonin by blocking its reuptake.
Paroxetine hydrochloride is a selective serotonin reuptake inhibitor (SSRI). The class raises synaptic serotonin by blocking the serotonin reuptake transporter, with relatively low affinity for other monoamine systems. The most clinically important supplement concerns are serotonergic and additive. St John's Wort is a hard exclude per the BNF and MHRA. 5-HTP is a hard exclude on theoretical and case-report grounds. Tryptophan, and at higher doses saffron extract and SAMe, sit on the same pathway. Serotonin syndrome is rare but recognisable. Tremor, hyperthermia, clonus, agitation. Metabolic profiles vary across the class. Sertraline runs on CYP2B6 and CYP2C19. Fluoxetine and paroxetine are CYP2D6 inhibitors. Citalopram and escitalopram run on CYP2C19. Individual SSRI pages give a sharper picture. Discontinuation needs taper, not stop. SSRI withdrawal symptoms are real and documented in NICE NG222, and any planned change should run through the prescribing GP.
Below are the 6 documented pairs we have explicitly assessed against Paroxetine hydrochloride in the Distil database: 2 red and 4 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
Additive serotonergic activity
5-HTP raises serotonin levels. Combined with an SSRI like paroxetine, it can cause serotonin syndrome. Do not combine.
St John's Wort and paroxetine both raise serotonin levels. Combined, they can cause serotonin syndrome. Do not combine.
Tryptophan is the building block your body uses to make serotonin, so adding it to paroxetine 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.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Rhodiola has mild effects on serotonin pathways that can add to paroxetine's. The one published case of this kind of reaction involved rhodiola taken alongside paroxetine, so this is the best-documented pair. 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.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
SAMe has its own antidepressant, serotonin-related activity, which may add to paroxetine'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 paroxetine dose has recently changed.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Saffron has its own antidepressant effect that may stack with paroxetine's. Most people tolerate the combination but discuss it with your GP, especially if your dose has recently changed.
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 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-backed compounds worth adding, and the ones worth dropping
It's a paid report: £79, or £49 for the first 25 customers. The interactions check is one section of it, and you can read a real one in full before you buy.
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.