Supplements and Lithium carbonate.
Lithium carbonate, sold under the brand names Priadel, Camcolit, Lithobid, Eskalith, is a mood stabiliser with a narrow therapeutic window requiring blood-level monitoring.
Lithium is a mood stabiliser. UK psychiatry prescribes it mostly for bipolar disorder maintenance and as augmentation in treatment-resistant depression. The therapeutic window is narrower than almost any other psychiatric medicine. Trough plasma levels are checked regularly because the gap between therapeutic and toxic concentrations sits at roughly 0.4 to 1.2 mmol/L. Levels are sensitive to hydration, sodium intake, and renal function. Three points matter for supplements. First, anything that affects renal sodium handling shifts lithium clearance. Sodium-restricted diets raise lithium levels. High sodium intake lowers them. Second, NSAIDs (ibuprofen, naproxen, diclofenac) reduce lithium clearance and have caused lithium toxicity in case reports. The BNF flags this. Third, dehydration from any cause (gastroenteritis, sauna use, intense exercise) can push lithium into the toxic range. Lithium taken over years also affects thyroid function and kidney function, both requiring annual monitoring. Any supplement decision should run through the prescribing psychiatrist, not a community pharmacist.
Below are the 11 documented pairs we have explicitly assessed against Lithium carbonate in the Distil database: 1 red and 10 amber. The pairs cluster around 6 mechanisms: Additive lithium load, Absorption interference, Additive thyroid suppression, Reduced mood-stabiliser effect, Narrow-therapeutic-index prescriber awareness, and 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 5 August 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Additive lithium load
Red Does Lithium Orotate interact with ?
We do not recommend taking a lithium supplement alongside prescribed lithium. Prescribed lithium is dosed against regular blood tests, and the gap between a helpful level and a toxic one is narrow. Supplemental lithium is not measured by those tests and is not part of the dose your psychiatrist set. At the roughly 5mg found in supplements the added amount is small, so this is not a warning about immediate harm: it is that the whole basis of lithium treatment is a level someone is controlling, and this adds to it uncontrolled. Talk to your prescriber before starting or stopping anything.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Absorption interference
Amber Does Psyllium Husk interact with ?
Psyllium may reduce how much lithium you absorb if you take them together, which could lower your lithium level below the range that keeps you well. Take your psyllium at least a few hours apart from your lithium, and keep to your scheduled lithium blood tests so any drop is picked up.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Additive thyroid suppression
Amber Does Iodine interact with ?
Lithium can affect the thyroid and commonly causes an underactive thyroid or goitre over time. Iodine intake interacts with that effect, so taking an iodine supplement on top of lithium can add to the risk of thyroid problems. If you take lithium, do not start an iodine supplement without discussing it with your GP, and make sure your thyroid is being monitored.
Evidence: Supported by human study data.
Reduced mood-stabiliser effect
Amber Does Myo-Inositol interact with ?
One of the leading explanations for how lithium steadies mood is that it lowers myo-inositol levels in the brain. Taking supplemental myo-inositol could in theory work against this and may reduce how well lithium controls mood, and there is a published report of mania in a person taking inositol. If you take lithium, do not start myo-inositol without discussing it with the doctor who manages your lithium first.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Narrow-therapeutic-index prescriber awareness
Amber Does Omega-3 EPA interact with ?
If you take lithium, tell the doctor who manages it what dose of omega-3 fish oil you take and keep to your usual lithium blood tests: lithium has a narrow safe range, and at higher fish oil doses (around 3 grams a day or more) omega-3 has a mild blood-thinning effect. Omega-3 does not appear to change your lithium blood level, and the two are often taken together on purpose, as omega-3 has been studied as a mood support added on top of lithium and is generally well tolerated.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Additive serotonergic activity
Amber Does 5-HTP interact with ?
5-HTP is the direct building block your body turns into serotonin, and lithium can increase serotonin activity in the brain. Combined, they may add up, which in theory can raise the risk of serotonin syndrome (agitation, sweating, tremor, fast heartbeat, confusion). Lithium also has a narrow safe range of its own, so tell your GP or specialist you take 5-HTP and watch for those symptoms, especially after any dose change.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does L-Tryptophan interact with ?
Tryptophan raises serotonin, and lithium increases your brain's response to serotonin. Used together they can add up, which may 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 a mild effect on serotonin pathways, and lithium can add to serotonin activity in the brain. In theory, taking them together could add to that effect. Lithium also has a narrow safe range, so it is worth telling the doctor who manages your lithium before you start rhodiola, watching for restlessness, sweating, tremor, or a racing heart, and keeping to your usual lithium blood tests.
Evidence: Based on an established mechanism, with no direct study of this exact combination yet.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does SAMe interact with ?
SAMe has its own antidepressant, serotonin-related activity, and lithium is often used alongside antidepressants in a way that can raise serotonin signalling. Adding SAMe may add to that effect. Most people tolerate the combination, but watch for restlessness, sweating, tremor, shivering, or a racing heart, and tell your GP or psychiatrist before stacking them, especially if your lithium dose or levels have 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 has its own mild antidepressant effect that appears to act on serotonin, and lithium also affects serotonin signalling when used for mood. Taking them together may add up. If you take lithium, tell your GP before adding saffron, as lithium needs careful monitoring.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does St John's Wort interact with ?
St John's Wort raises serotonin activity, and lithium can add to serotonergic effects, so combining them may raise the risk of serotonin syndrome (agitation, sweating, tremor, confusion). Lithium also needs careful blood-level monitoring, so speak to your GP or specialist before adding St John's Wort.
Evidence: Limited human data, based on case reports and a known mechanism.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
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 methodologyA full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
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