Ranked by how strong the human evidence is — best supported first.
Best supportedDigestive comfortNot enough evidence· no source yetThen, in order
An essential trace element serving as the cofactor for sulfite oxidase, xanthine oxidase and aldehyde oxidase. Requirements are measured in micrograms and ordinary diets supply several times them.
Molybdenum deficiency has been documented essentially twice: in a patient on long-term parenteral nutrition without it, and in a rare inborn error of cofactor synthesis. Beyond that, deficiency does not occur in people eating food, because legumes, grains and nuts supply far more than the 45 µg/day requirement. It appears in multivitamins and "trace mineral" blends where it addresses nothing, and it is occasionally sold on the theory that it helps with sulphite sensitivity or candida — neither of which has controlled evidence. The upper limit of 2,000 µg/day is generous, but high intake interferes with copper metabolism, which is the one real reason for restraint.
Regulation: The RDA is 45 µg/day for adults with a Tolerable Upper Intake Level of 2,000 µg/day. Sold as a dietary supplement with no pre-market efficacy review.
The amounts, forms and durations published trials of Molybdenum actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Recommended Dietary Allowance, adults
45 µg
Typical intakes are around 75–250 µg/day, comfortably above the requirement, which is why deficiency does not occur outside parenteral nutrition and rare genetic disorders.
Studied for Tolerable Upper Intake Level, adults
2000 µg
Set largely on animal reproductive toxicity data because human toxicity is so rarely observed. Supplements typically supply 50–500 µg.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.
No timing has been studied and none is likely to matter at these intakes.
Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
Molybdenum is sold for sulphite sensitivity and for "candida die-off" symptoms. Neither claim has controlled human evidence, and the latter rests on a concept without an accepted clinical definition.
Not enough evidence. Not enough human research to say anything useful yet.
Molybdenum-dependent enzymes handle sulphur amino acid metabolism and purine breakdown, but there is no evidence that supplementing above dietary intake changes energy or any other outcome in people who are not deficient — a group that includes virtually everyone eating food.
Not enough evidence. Not enough human research to say anything useful yet.
Systematic review · Journal of inherited metabolic disease · 2024 · PMID 38627985
Deep research mode adds each paper’s own conclusion and stated limitations.
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Interaction
Interacts withCopper supplements, penicillamine
High molybdenum intake increases copper excretion — the basis for tetrathiomolybdate being used as a copper-lowering drug in Wilson disease. Sustained high supplemental intake could contribute to copper depletion, particularly alongside high-dose zinc.
Too much
Occupational and high dietary exposure in some regions has been associated with raised uric acid and gout-like joint symptoms, since molybdenum-dependent xanthine oxidase produces uric acid.
Worth knowing
Molybdenum is excreted in urine, so reduced kidney function allows accumulation and lowers the practical safety margin.
Worth knowing
Outside long-term parenteral nutrition and a rare genetic cofactor disorder, dietary molybdenum deficiency has not been described. Supplementing it corrects nothing.
The whole-food form, where one exists. The evidence for a concentrated extract rarely transfers to the food, or the other way round — these are cross-links, not equivalents.