Ammonium Molybdate

Evidence Level

Limited

2 Clinical Trials

4 Documented Benefits

2/5 Evidence Score

Ammonium molybdate ((NH4)6Mo7O24·4H2O, roughly 54% elemental molybdenum) is a soluble inorganic molybdenum compound used mainly as the molybdenum source in liquid molybdenum drops and some clinical formulations. Like other soluble molybdenum forms, it is well absorbed and supplies molybdenum for the molybdenum cofactor used by sulfite oxidase, xanthine oxidase, and aldehyde oxidase. It is a commodity ingredient with no form-specific efficacy trials; the human evidence for molybdenum comes from a rare parenteral-nutrition deficiency case and metabolic absorption studies rather than studies of ammonium molybdate specifically. Molybdenum is essential, low in toxicity, and rarely deficient in healthy people.

Studied Dose RDA 45 mcg/day elemental Mo. Liquid products typically provide 25-500 mcg/day per serving. Tolerable upper limit 2,000 mcg/day.

Active Compound Ammonium molybdate tetrahydrate ((NH4)6Mo7O24·4H2O), a soluble inorganic molybdenum salt providing roughly 54% elemental molybdenum; supplies molybdate for the molybdenum cofactor.

Sulfite Metabolism Support

Molybdenum is the cofactor for sulfite oxidase, the enzyme that converts sulfite to sulfate. Ammonium molybdate supplies molybdenum to help ensure this enzyme can support normal metabolism of sulfites and sulfur-containing compounds.

Supported by Trial 1, Trial 2

Liquid-Delivery Molybdenum Source

Because it is highly soluble, ammonium molybdate is well suited to liquid molybdenum drops that allow flexible, low-dose intake. This makes it a practical way to supply small, adjustable amounts of the mineral.

Supported by Trial 2, Trial 1

Molybdenum Cofactor Support

Ammonium molybdate provides molybdenum used to build the cofactor required by sulfite oxidase, xanthine oxidase, and aldehyde oxidase, helping maintain normal activity of these detoxification and purine-processing enzymes.

Supported by Trial 1

Maintains Adequate Molybdenum Status

For individuals with low molybdenum intake, ammonium molybdate offers a well-absorbed source that helps maintain adequate levels of this essential trace mineral and the enzymes that depend on its cofactor.

Supported by Trial 2, Trial 1

Molybdenum Cofactor Formation

Molybdate from ammonium molybdate is incorporated into the pterin-based molybdenum cofactor (Moco), the prosthetic group that activates all human molybdenum-dependent enzymes and sets their maximal activity.

Sulfite Oxidase Activation

Using the molybdenum cofactor, sulfite oxidase oxidizes sulfite to sulfate, a step essential for safe metabolism of sulfur amino acids and the molybdenum function most clearly important to human health.

Xanthine and Aldehyde Oxidase Function

Molybdenum cofactor also enables xanthine oxidase and aldehyde oxidase, which convert purines to uric acid and process aldehydes and some drugs, contributing to nitrogen handling and xenobiotic metabolism.

Efficient Absorption and Excretion

As a soluble salt, molybdate is efficiently absorbed and its body level is regulated mainly through urinary excretion, keeping cofactor supply stable and buffering against both inadequate and excessive intake.

Molybdate Therapy in Parenteral-Nutrition Deficiency

Study info

Clinical case report of a patient on prolonged molybdenum-free total parenteral nutrition who developed sulfur amino-acid intolerance and was treated with supplemental ammonium molybdate (300 mcg/day).

Population & duration

Single long-term total parenteral nutrition patient.

Findings

The patient showed high methionine, low uric acid, and neurological symptoms consistent with impaired sulfite oxidase activity; ammonium molybdate normalized sulfur metabolism and resolved symptoms. This case used ammonium molybdate specifically and is the key human evidence for molybdenum essentiality.

Molybdenum Absorption and Retention with Stable Isotopes

Study info

Controlled metabolic study using stable molybdenum isotopes in young men across low and high intakes, measuring absorption, urinary excretion, and retention during depletion and repletion.

Population & duration

Healthy young men in a metabolic ward.

Findings

Soluble molybdenum was efficiently absorbed across a wide intake range, with the body regulating status through urinary excretion. The findings apply to soluble forms such as ammonium molybdate, supporting high bioavailability, though they are not specific to this exact compound.

Common Potential side effects

Molybdenum has very low toxicity at usual supplement doses and is generally well tolerated.

Very high intakes may interfere with copper and contribute to copper deficiency over time.

Excessive molybdenum has been linked to joint pain and gout-like symptoms.

Concentrated liquid drops should be measured carefully to avoid unintentionally large doses.

Staying under the 2,000 mcg/day adult upper limit avoids essentially all reported adverse effects.

Important Drug interactions

High-dose molybdenum can lower copper levels, opposing copper supplements or worsening deficiency.

Because xanthine oxidase generates uric acid, very high molybdenum may matter in people with gout.

Very high dietary sulfur or sulfate can increase molybdenum loss and reduce its retention.

No significant prescription-drug interactions are established at typical molybdenum doses.

Frequently asked questions about Ammonium Molybdate

What is ammonium molybdate?

Ammonium molybdate is a molybdenum salt used as a source of the trace mineral molybdenum in some supplements and fortified products. Like other forms, it supplies molybdenum for enzyme function.

How much ammonium molybdate should I take?

Molybdenum requirements are tiny (RDA 45 mcg per day), usually met by diet. Supplements provide small amounts, and the upper limit is about 2,000 mcg per day. There is rarely a need for high doses.

What is ammonium molybdate used for?

It provides molybdenum to support enzymes that break down sulfur-containing compounds and certain waste products. It is one of several interchangeable molybdenum sources used in supplements.

Is ammonium molybdate safe?

At the small amounts used in supplements it is generally safe. Excess molybdenum can interfere with copper metabolism, so stay within recommended limits; most people do not need to supplement it at all.

What is the recommended dosage of Ammonium Molybdate?

The clinically studied dose is RDA 45 mcg/day elemental Mo. Liquid products typically provide 25-500 mcg/day per serving. Tolerable upper limit 2,000 mcg/day. Always follow the product label and check with a healthcare provider for personal advice.

Is Ammonium Molybdate safe, and does it have side effects?

For most healthy adults, Ammonium Molybdate is well tolerated at studied doses. Reported effects can include: Molybdenum has very low toxicity at usual supplement doses and is generally well tolerated. Very high intakes may interfere with copper and contribute to copper deficiency over time. It may also interact with some medications. Ammonium Molybdate is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Ammonium Molybdate interact with any medications?

Possible interactions include: High-dose molybdenum can lower copper levels, opposing copper supplements or worsening deficiency. Because xanthine oxidase generates uric acid, very high molybdenum may matter in people with gout. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Ammonium Molybdate?

NutraSmarts rates the evidence for Ammonium Molybdate as Limited (2 out of 5). It is backed by 2 clinical trials and 2 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(2 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

Abumrad NN, Schneider AJ, Steel D, Rogers LS. Amino acid intolerance during prolonged total parenteral nutrition reversed by molybdate therapy. Am J Clin Nutr. 1981;34(11):2551-9. doi: 10.1093/ajcn/34.11.2551.PubMedUsed to support: Human case of molybdenum deficiency on molybdenum-free TPN in which supplemental ammonium molybdate (300 mcg/day) reversed sulfur amino-acid intolerance and normalized related biochemistry; the principal human evidence using ammonium molybdate specifically
Turnlund JR, Keyes WR, Peiffer GL, Chiang G. Molybdenum absorption, excretion, and retention studied with stable isotopes in young men during depletion and repletion. Am J Clin Nutr. 1995;61(5):1102-9. doi: 10.1093/ajcn/61.5.1102.PubMedUsed to support: Stable-isotope study showing soluble molybdenum is efficiently absorbed with urinary-regulated retention; supports high bioavailability of soluble molybdenum forms such as ammonium molybdate, though not specific to this exact salt

Ammonium Molybdate

Benefits

Sulfite Metabolism Support

Liquid-Delivery Molybdenum Source

Molybdenum Cofactor Support

Maintains Adequate Molybdenum Status

Mechanism of action

Molybdenum Cofactor Formation1

Sulfite Oxidase Activation1

Xanthine and Aldehyde Oxidase Function1

Efficient Absorption and Excretion2

Clinical trials

Side effects and drug interactions