Magnesium orotate is the magnesium salt of orotic acid. It delivers about 6.5% elemental magnesium by weight, dissolves poorly in water, and carries a second bioactive component, orotic acid, that no other common magnesium salt provides. Those three properties explain most of what distinguishes it from citrate, bisglycinate, oxide, or chloride, and they also explain why it occupies an unusual regulatory position: it is sold as a medicine in Germany and as a supplement in the United States, but it is not an authorised magnesium source for food supplements in the European Union. This article sets out the chemistry, the differences that matter to formulators, and what the clinical evidence for magnesium orotate benefits does and does not show.

What Magnesium Orotate Is

Magnesium orotate dihydrate has the formula C10H6MgN4O8 · 2H2O and a molecular weight of 370.5 g/mol. One magnesium ion is bound to two orotate anions. Because the orotate anion is large relative to the magnesium ion, the salt contains only 6.42% to 6.62% magnesium by mass, according to the specification reviewed in the 2025 EFSA safety opinion on magnesium orotate dihydrate. The same document describes the material as slightly soluble in water and practically insoluble in ethanol or methanol, and notes that it is produced by reacting a hot orotic acid solution with a magnesium salt, then crystallising and purifying the product.

Orotic acid is an intermediate in pyrimidine biosynthesis, the pathway that produces uridine monophosphate and, downstream, the building blocks of RNA and DNA. It was once called vitamin B13, but essentiality was never demonstrated and the vitamin designation was dropped. Orotic acid occurs naturally in ruminant milk: EFSA cites 20 to 100 mg/L in cows' milk and 200 to 400 mg/L in goat's and sheep's milk. Proponents of magnesium orotate argue that orotate supports ATP and glycogen synthesis in stressed cardiac tissue and acts as a "magnesium-fixing agent" that helps retain intracellular magnesium; Classen's 2004 review summarises this rationale. It is a mechanistic hypothesis drawn largely from animal work, not an established clinical effect.

How Magnesium Orotate Differs from Other Magnesium Forms

Elemental Magnesium Content

Elemental content determines how much material a dose requires. Values below are calculated from the molecular formula of each salt as named; the orotate figure is the analytical specification reported to EFSA. Reported percentages shift with hydrate state and stoichiometry, so verify against the certificate of analysis for the specific material.

• Magnesium oxide: about 60%

• Magnesium citrate (trimagnesium dicitrate, anhydrous): about 16%

• Magnesium malate: about 15%

• Magnesium bisglycinate: about 14%

• Magnesium chloride hexahydrate: about 12%

• Magnesium L-threonate: about 7% to 8%

• Magnesium orotate dihydrate: about 6.5%

Delivering 100 mg of elemental magnesium requires roughly 1,540 mg of magnesium orotate dihydrate, compared with about 170 mg of magnesium oxide or 620 mg of trimagnesium citrate. The 6,000 mg daily dose used in the largest clinical trial (discussed below) supplied roughly 390 mg of magnesium and about 4,900 mg of orotic acid. For a broader comparison of forms, see our guides to magnesium chelates and magnesium bisglycinate compared with other forms.

Solubility and Gastrointestinal Behaviour

Magnesium orotate dissolves poorly in water. Reported solubility figures vary widely between supplier documents, from roughly 0.01 g/L to 1.7 g/L at about 25 °C depending on method and hydrate, but all place it well below citrate or chloride at neutral pH. Classen notes that, because it dissociates slowly, it does not neutralise gastric acid and produces little laxative effect compared with readily dissociable salts. In the in vitro gastrointestinal model published by Blancquaert and colleagues in 2019, a magnesium orotate tablet released only 32% of its magnesium under simulated fasted stomach conditions and 46% under fed conditions, yet showed the highest simulated small-intestinal absorption efficiency of the fifteen products tested (90% fasted, 85% fed). EFSA reviewed that study and judged it insufficient to establish bioavailability, and the orotate product was not among the two formulations the authors carried forward to human testing. The contrast with magnesium chloride, which dissolves freely and releases ions rapidly, is pronounced. Our guide on whether magnesium is water soluble covers the full range.

Bioavailability: What is Actually Known

No published human study directly compares magnesium orotate with citrate, bisglycinate, or oxide on serum or urinary magnesium. The NIH Office of Dietary Supplements summarises the comparative literature as follows: small studies have found that magnesium in the aspartate, citrate, lactate, and chloride forms is absorbed more completely than magnesium oxide and magnesium sulfate. Orotate does not appear in those head-to-head studies. Claims that orotate is "the most bioavailable form of magnesium" rest on in vitro data, on the theoretical argument about orotate as a carrier, and on the clinical trials described next, none of which measured absorption against a comparator salt. The EFSA panel explicitly declined to assess bioavailability of magnesium from orotate relative to natural food sources because the safety questions were unresolved.

What the Clinical Evidence Supports

The evidence base for magnesium orotate is concentrated in cardiovascular medicine, mostly in small European trials from the 1990s and 2000s using the German pharmaceutical Magnerot. The studies are summarised here with their sample sizes and limitations.

Severe Heart Failure

The most cited trial is the MACH study by Stepura and Martynow, published in the International Journal of Cardiology in 2009. Seventy-nine patients with NYHA class IV heart failure on optimal medical therapy were randomised to magnesium orotate (6,000 mg daily for one month, then 3,000 mg daily for about eleven months; n = 40) or placebo (n = 39). After roughly one year, survival was 75.7% in the orotate group versus 51.6% on placebo (p < 0.05). Clinical symptoms improved in 38.5% of orotate patients and deteriorated in 56.3% of placebo patients. The trial was single-centre, small, and has not been replicated in a larger multicentre study, so it is best described as a positive signal rather than established therapy.

Coronary Heart Disease and Exercise Tolerance

Geiss and colleagues (1998) ran a four-week double-blind pilot in 14 patients with coronary heart disease and left-ventricular dysfunction. Magnesium orotate at 3 × 1 g daily significantly reduced left-ventricular end-systolic volume (p = 0.016), increased ejection fraction (p = 0.035), and increased exercise duration (p = 0.011). Fourteen participants is a hypothesis-generating sample.

Athletic Performance

Golf, Bender, and Grüttner (1998) studied 23 competitive triathletes who took either placebo or 17 mmol of magnesium per day as orotate (about 410 mg of magnesium) for four weeks before a swim-bike-run event. Swimming, cycling, and running times decreased in the orotate group, and the metabolic profile during exercise differed from controls (a larger rise in glucose, a fall rather than a rise in insulin). This is a single small trial in a specific population and has not been confirmed.

Pooled Cardiovascular Data

A 2015 Russian-language meta-analysis by Torshin and colleagues pooled 19 randomised trials totalling 603 patients on magnesium orotate and 587 on placebo, with a mean dose of 1,878 mg per day. It reported reduced risk of hypomagnesaemia, exercise intolerance, premature contractions, and several other outcomes. Many of the included trials concern mitral valve prolapse and appeared in Russian-language journals, several from the same research groups, which limits independent verification and generalisability.

Other Indications

Evidence outside cardiology is thin. A randomised pilot in idiopathic male infertility gave 3,000 mg per day for 90 days to ten men and found no improvement in sperm parameters or pregnancy rates, though ionised magnesium in seminal plasma rose. A 2024 randomised double-blind trial in 120 adults with major depressive disorder tested a combination of probiotics, magnesium orotate, and coenzyme Q10 for eight weeks and reported lower frequency of depressive episodes and reduced self-rated anxiety versus placebo; because the product combined several actives, the result cannot be attributed to orotate. There are no adequately powered trials of magnesium orotate for sleep, general anxiety, or muscle cramps; the general evidence on magnesium and cramps is reviewed in our article on magnesium for muscle cramps.

Summary of the Evidence

Magnesium orotate is licensed in Germany as a medicine for treating magnesium deficiency, and the trials above consistently report correction of hypomagnesaemia. The distinctive claims, better cardiac outcomes and improved exercise capacity, rest on a handful of small trials with a total of a few hundred participants, most using 3 to 6 g per day of the salt. Whether the orotate component adds anything beyond the magnesium has not been tested in a design that isolates it. Formulators should treat orotate-specific benefit claims as unproven and confine structure-function language to what magnesium itself supports.

Safety and Regulatory Status

The Orotic Acid Question

Safety assessment of magnesium orotate hinges on orotic acid exposure, not on magnesium. In 2009 the EFSA ANS Panel reviewed a series of rat studies in which orotic acid promoted tumour formation in the presence of known initiators, with effects seen at a dietary level of 1% (about 500 mg/kg body weight per day) but not at 0.1%. The Panel derived a no-observed-adverse-effect level of 50 mg/kg body weight per day for orotic acid. The proposed supplement use at that time (up to 3,811 mg magnesium orotate per day, delivering about 3,192 mg orotate) gave a margin of safety of 0.94, which the Panel considered inadequate. The 2025 NDA Panel opinion repeated this analysis for a proposed maximum of 6,100 mg per day (about 5,000 mg orotic acid and 400 mg magnesium), calculated a margin of 0.7, noted that the applicant provided no toxicological studies on the substance, and concluded that safety could not be established under the proposed conditions of use. The Panel also observed that 400 mg of supplemental magnesium exceeds the EU tolerable upper intake level of 250 mg per day for supplemental magnesium.

The German Federal Institute for Drugs and Medical Devices took a different view in a 2014 letter, placing the NOAEL at 500 mg/kg body weight per day and regarding 6.2 g of orotate daily as acceptable within a medicinal context. EFSA noted that no supporting arguments were provided. The disagreement is real and unresolved; a formulator should present both positions rather than pick one.

European Union

Magnesium orotate dihydrate is not on the list of permitted magnesium sources for food supplements under Directive 2002/46/EC, and the EFSA opinion confirms it had not been authorised as of 2025. Following the negative opinion, the European Commission issued an Implementing Decision on 1 April 2026 terminating the novel food authorisation procedure for magnesium orotate dihydrate without updating the Union list. Parallel procedures for lithium orotate and ferrous orotate were also terminated. Magnesium orotate remains available in Germany as a licensed medicine (Magnerot Classic N, 500 mg tablets) and, according to the EFSA document, is offered as a food supplement in Austria at 550 mg per capsule, but an EU-wide supplement launch is not currently possible.

United States

In the United States, magnesium orotate is sold as a dietary supplement ingredient. Under the Dietary Supplement Health and Education Act of 1994, FDA states that manufacturers and distributors are responsible for evaluating the safety and labelling of their products before marketing, and FDA acts against adulterated or misbranded products after they reach the market. No GRAS determination for magnesium orotate in conventional foods is documented, so use outside supplements would require separate regulatory review. The relevant intake benchmarks come from the Food and Nutrition Board, as reported by the NIH Office of Dietary Supplements: recommended dietary allowances of 400 to 420 mg per day for adult men and 310 to 320 mg for adult women, and a tolerable upper intake level of 350 mg per day for supplemental magnesium in adults. The 3 to 6 g daily doses of magnesium orotate used in the cardiology trials deliver 195 to 390 mg of magnesium, so the upper end of that range exceeds the US supplemental UL and the whole range exceeds the EU figure.

Formulation Considerations

• Dose mass. At 6.5% magnesium, a meaningful dose is large. A 500 mg tablet supplies about 32 mg of magnesium, roughly 8% of the adult male RDA. Reaching 100 mg per serving in a capsule or tablet means well over 1.5 g of active, which pushes products toward multi-unit servings. This is the format pressure that drives interest in alternatives to pills; our article on pill fatigue discusses the consumer side.

• Beverage compatibility. Slight water solubility rules out clear ready-to-drink or shot formats at any useful magnesium level without a solubilisation strategy. Suspensions are possible but face sedimentation and dosing-uniformity issues. Formulators who need clear, low-solids beverages typically evaluate more soluble salts such as citrate, chloride, or gluconate; our comparison of magnesium gluconate covers one such option.

• Orotic acid load and labelling. Because the orotate anion accounts for roughly 84% of the dihydrate by mass, any product must account for orotic acid intake alongside magnesium. Given the EFSA position, that figure deserves explicit consideration in the safety file even for non-EU markets.

Our own work sits at the second of these constraints. We convert hard-to-solubilise nutrients, including magnesium among the actives listed on our homepage, into stable water-soluble liquid and powder ingredients using a physical processing method with natural stabilisers rather than synthetic emulsifiers. The resulting ingredients hold active payloads of 10% or more, disperse with minimal agitation, and have shown a minimum 24-month shelf life in real-time studies, including after pasteurisation and carbonation. Solubilisation changes how an ingredient behaves in a beverage matrix; it does not change its regulatory status or add to its clinical evidence, and any project involving orotate would need to be scoped against the constraints above. Teams evaluating magnesium delivery in RTD beverages, shots, or powders can discuss the specific form and dose with us.

Frequently Asked Questions

What are the main magnesium orotate benefits according to research?

The documented benefits come from small cardiology trials. A 79-patient randomised trial in severe heart failure reported one-year survival of 75.7% with magnesium orotate versus 51.6% with placebo, and a 14-patient pilot in coronary heart disease reported improved ejection fraction and exercise duration. A 23-athlete trial reported faster triathlon segment times. All of these used 3 to 6 g of the salt per day, none has been replicated at scale, and none isolated the effect of orotate from the effect of magnesium.

How much elemental magnesium is in magnesium orotate?

Magnesium orotate dihydrate contains 6.42% to 6.62% magnesium by weight, according to the specification reviewed by EFSA. A 500 mg tablet therefore provides about 32 mg of magnesium. By comparison, magnesium oxide is about 60% magnesium, citrate about 16%, and bisglycinate about 14%.

Is magnesium orotate more bioavailable than other forms?

No human study has compared magnesium orotate directly with other salts on absorption. An in vitro digestion model showed low release in simulated stomach conditions but high simulated intestinal absorption; EFSA judged that study insufficient to establish bioavailability. Human comparative data summarised by the NIH Office of Dietary Supplements cover citrate, chloride, lactate, aspartate, oxide, and sulfate, not orotate.

Is magnesium orotate approved in the EU?

No. It is not a permitted magnesium source for food supplements under Directive 2002/46/EC. EFSA concluded in 2025 that its safety could not be established at the proposed use levels because of orotic acid exposure, and the European Commission terminated the novel food authorisation procedure on 1 April 2026. It remains available in Germany as a licensed medicinal product.

Why is orotic acid a safety concern?

Several rat studies showed that orotic acid promotes tumour formation when combined with known tumour initiators, at dietary levels around 500 mg/kg body weight per day. EFSA derived a NOAEL of 50 mg/kg body weight per day and found that proposed supplement doses of 3 to 6 g of magnesium orotate deliver orotic acid at or above that level for a 70 kg adult. Germany's medicines regulator has taken a less restrictive view. No human toxicology data resolve the question.

Can magnesium orotate be used in beverages?

Not readily. It is only slightly soluble in water, so clear drinks and shots at useful magnesium levels would require a solubilisation approach, and suspensions raise sedimentation and dosing concerns. Beverage formulators typically evaluate more soluble salts such as citrate, chloride, or gluconate for clear formats.

This article is for educational purposes and does not constitute medical advice. Magnesium orotate has been studied mainly at high doses in patients with cardiovascular disease under medical supervision. Consult a qualified healthcare provider before starting any new supplement, particularly if you have kidney disease, heart disease, or take prescription medication.