Supplements and Venlafaxine.
Venlafaxine, sold under the brand names Efexor, Efexor XL, Venlalic XL, Foraven XL, is an antidepressant: depending on the agent, it acts on serotonin, noradrenaline, or both.
Venlafaxine is an SNRI (serotonin and noradrenaline reuptake inhibitor). The BNF groups it with "other antidepressants" but the clinical class is SNRI, distinct from the SSRIs. At 75mg it acts predominantly as an SSRI. The noradrenergic activity emerges above 150mg. Three points sit at the centre of clinical prescribing in the UK. First, blood pressure rises with dose; NICE flags monitoring above 200mg. Second, the discontinuation syndrome is heavier than for most SSRIs. The half life is short and the syndrome scales with dose. Abrupt stops generate brain zaps, dizziness, and symptoms resembling flu. Taper is longer and slower than sertraline or citalopram. Third, the QT prolongation signal is real at higher doses. Supplement interactions of greatest concern are the same serotonergic set as the SSRIs (St John's Wort hard exclude, 5-HTP hard exclude, saffron, tryptophan), plus additive BP effect from sympathomimetic supplements at the higher dose range.
Below are the 6 documented pairs we have explicitly assessed against Venlafaxine 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 SNRI like venlafaxine, it can cause serotonin syndrome. Do not combine.
St John's Wort and venlafaxine 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 venlafaxine 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, and venlafaxine raises serotonin as part of how it works. Taking them together may add to that effect. 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 venlafaxine'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 venlafaxine dose has recently changed.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Saffron has its own antidepressant effect that may stack with venlafaxine's serotonergic component. 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.