Uridine Monophosphate

Pharmacology & Research

Uridine monophosphate (UMP) is a pyrimidine nucleotide — the phosphorylated form of the nucleoside uridine, one of the four building blocks of RNA — sold as a nootropic supplement on the premise that it supplies a rate-limiting precursor for brain phosphatidylcholine synthesis. The evidence base has an unusual shape for a nootropic: the animal pharmacology is extensive and mechanistically coherent (a 20-year program from Richard Wurtman’s group), but almost none of the human efficacy data tests UMP alone. Instead, the clinical trials test UMP as one ingredient (alongside choline, DHA, EPA, phospholipids, and B-vitamins) in a proprietary medical-food blend (Fortasyn Connect, marketed as Souvenaid), in a population with Alzheimer’s disease or prodromal cognitive decline — not in healthy adults taking UMP as a standalone nootropic. The distinction between a multi-nutrient effect in a diseased brain and UMP monotherapy in a healthy one should frame every claim on this page, and the bioavailability caveat matters too: oral uridine itself is poorly and inconsistently absorbed, which is part of why formulators use UMP or triacetyluridine rather than free uridine.

1. Prodromal/mild Alzheimer’s decline

The founding proof-of-concept trial gave 225 patients with mild Alzheimer’s a medical food containing UMP, choline, DHA/EPA and B-vitamin cofactors (Souvenaid) or placebo for 12 weeks: supplementation improved memory (delayed verbal recall) in mild AD patients, while other cognitive measures were unchanged ^{1Reference 1Scheltens et al. · 2010RCTEfficacy of a medical food in mild Alzheimer’s disease: a randomized, controlled trial — [RCT]View study →}. A follow-up 24-week randomized trial in drug-naïve mild AD patients found the NTB memory-domain Z-score was significantly increased in the active versus the control group over the intervention period (p = 0.023; Cohen’s d = 0.21), with a trend on the total composite score and a difference in EEG functional connectivity favoring the active group ^{2Reference 2Scheltens et al. · 2012RCTEfficacy of Souvenaid in mild Alzheimer’s disease: results from a randomized, controlled trial — [RCT]View study →}. The larger LipiDiDiet trial, in prodromal (pre-dementia) Alzheimer’s disease, found no significant effect on its primary 24-month cognitive endpoint but did find group differences on secondary endpoints of disease progression (cognition, function and hippocampal atrophy), with decline in the control group lower than expected, likely underpowering the trial ^{4Reference 4Soininen et al. · 2017RCTSoininen, H., Solomon, A., Visser, P. J., et al. (2017). 24-month intervention with a specific multinutrient in people with prodromal Alzheimer’s disease (LipiDiDiet): a randomised, double-blind, controlled trial — [RCT]. The Lancet Neurology. https://pubmed.ncbi.nlm.nih.gov/29097166/View study →}. Extended follow-up strengthened this signal: over 36 months, significant reductions in decline were observed for the NTB 5-item composite, Clinical Dementia Rating–Sum of Boxes, memory, and brain-atrophy measures, with small-to-medium effect sizes (Cohen’s d 0.25–0.31) similar to established AD treatments ^{5Reference 5Soininen et al. · 2021RCTSoininen, H., Solomon, A., Visser, P. J., et al. (2021). 36-month LipiDiDiet multinutrient clinical trial in prodromal Alzheimer’s disease — [RCT]. Alzheimer’s & Dementia. https://pubmed.ncbi.nlm.nih.gov/32920957/View study →}, and a post-hoc reanalysis using Bayesian modelling found the blend was associated with significantly less clinical decline over 36 months ^{6Reference 6Hendrix et al. · 2023RCTCombined evidence for a long-term, clinical slowing effect of multinutrient intervention in prodromal Alzheimer’s disease: post-hoc analysis of 3-year LipiDiDiet data — [post-hoc RCT analysis]View study →}. A 2020 Cochrane systematic review concluded that Souvenaid “probably results in slight improvement, which is below estimates of meaningful change,” in prodromal AD after 24 months, and probably does not reduce the risk of progression to dementia ^{7Reference 7Burckhardt et al. · 2020Systematic reviewSouvenaid for Alzheimer’s disease — [Cochrane systematic review]View study →}. A small 6-month proof-of-concept trial combining the medical food with a multidomain lifestyle intervention in prodromal AD found less cognitive-functional decline in the combination arm in exploratory analysis ^{8Reference 8Thunborg et al. · 2024RCTIntegrating a multimodal lifestyle intervention with medical food in prodromal Alzheimer’s disease: the MIND-ADmini randomized controlled trial — [RCT, pilot]View study →}.

Gap: every positive signal comes from the five-ingredient Fortasyn Connect blend, not UMP in isolation — UMP’s individual contribution cannot be separated from choline, DHA/EPA, or the B-vitamin cofactors. Even the most favorable reading (Cochrane’s “slight improvement… below estimates of meaningful change”) is a modest effect in a diseased population, not a general cognitive enhancer for the healthy.

2. Brain phospholipid/membrane synthesis

The mechanistic case for UMP rests on the “precursor supply” hypothesis: brain phosphatidylcholine synthesis via the Kennedy pathway requires uridine (as CDP-choline’s precursor), choline, and a fatty acid simultaneously, and supplying all three should increase synaptic membrane formation. In the one study to test this directly in humans, 17 healthy men underwent brain ³¹P-MRS before and after seven days of 2 g/day oral uridine or placebo, a protocol designed to detect changes in phosphomonoester and phosphodiester membrane-precursor pools ^{11Reference 11Agarwal et al. · 2010Short-term administration of uridine increases brain membrane phospholipid precursors in healthy adults: a ³¹P magnetic resonance spectroscopy study at 4T — [MRS study]View study →}. This confirms UMP/uridine does something measurable to brain phospholipid chemistry in living humans within a week — the mechanistic premise is real — but the study did not test, and cannot speak to, any cognitive or clinical outcome.

Gap: n=17, healthy young men only, one week, biochemical (MRS) endpoint only — no behavioral or cognitive measure was taken, so this cannot be read as evidence of a functional brain benefit.

3. Bipolar depression

Because CDP-choline/phospholipid turnover has been implicated in bipolar disorder, uridine’s mitochondrial and membrane effects were tested as an antidepressant strategy using triacetyluridine (TAU), an acetylated, more bioavailable uridine prodrug. In an open-label pilot, 11 patients with bipolar depression received up to 18 g/day TAU for 6 weeks: MADRS depression scores fell progressively (roughly −24% by week 2 to −43% by week 4), and TAU responders showed a significant difference from non-responders in brain pH changes, consistent with a mitochondrial bioenergetic effect ^{10Reference 10Jensen et al. · 2008Triacetyluridine (TAU) decreases depressive symptoms and increases brain pH in bipolar patients — [open-label pilot]View study →}. This is a real, brain-imaging-correlated signal, but it used triacetyluridine — a different, more bioavailable molecule than the UMP sold as a supplement — at doses far above typical nootropic use.

Gap: open-label, no placebo arm, no blinding, n=11, and tested a prodrug (TAU) rather than UMP itself — the result cannot be assumed to transfer to standard UMP supplementation.

4. Cognitive enhancement in healthy adults

This is the application UMP is actually marketed for, and it has essentially no direct human evidence. The mechanistic groundwork is entirely rodent: dietary UMP increased striatal acetylcholine release in aged rats ^{17Reference 17Wang et al. · 2007AnimalDietary supplementation with uridine-5’-monophosphate increases acetylcholine level and release in striatum of aged rats — [rat]View study →}, increased potassium-evoked dopamine release and neurite outgrowth in aged rats ^{16Reference 16Wang et al. · 2005AnimalDietary uridine-5’-monophosphate supplementation increases potassium-evoked dopamine release and promotes neurite outgrowth in aged rats — [rat]View study →}, raised brain CDP-choline levels in gerbils ^{14Reference 14Cansev et al. · 2005Oral uridine-5’-monophosphate (UMP) increases brain CDP-choline levels in gerbils — [gerbil]View study →}, and — combined with choline and DHA — increased synaptic proteins, dendritic spines, and learning/memory performance in gerbils and in a rat cognitive-deficit model ^{12,15,18,19,20Reference 12De Bruin et al. · 2003AnimalCombined uridine and choline administration improves cognitive deficits in spontaneously hypertensive rats — [rat]View study →Reference 15Wurtman et al. · 2006Synaptic proteins and phospholipids are increased in gerbil brain by administering uridine plus docosahexaenoic acid — [gerbil]View study →Reference 18Sakamoto et al. · 2007Oral supplementation with DHA and uridine-5’-monophosphate increases dendritic spine density in adult gerbil hippocampus — [gerbil]View study →Reference 19Wurtman et al. · 2009ReviewSynapse formation is enhanced by oral administration of uridine and DHA, the circulating precursors of brain phosphatides — [review/gerbil]View study →Reference 20Holguin et al. · 2008Dietary uridine enhances the improvement in learning and memory produced by administering DHA to gerbils — [gerbil]View study →}. Uridine has also been shown in mice to modulate striatal dopamine release in a seizure model ^{21Reference 21Wang et al. · 2018AnimalAntiepileptic effect of uridine may be caused by regulating dopamine release and receptor expression in corpus striatum — [mouse]View study →}. The one pediatric human trial to test a uridine-containing combination (DHA + vitamin D3 + uridine) alongside cognitive/motor training in prepubescent children raised blood DHA and vitamin D levels but could not demonstrate any significant effect on the cognitive tests ^{22Reference 22Hansen et al. · 2017RCTSupplementation of DHA, vitamin D3 and uridine with six weeks of cognitive and motor training in prepubescent children: a pilot study — [RCT pilot, null]View study →}. A related preterm-infant nutrition trial (DHA + choline + UMP) is registered and still reporting long-term developmental outcomes ^{23Reference 23Janson et al. · 2024RCTDolphin CONTINUE: a multi-center RCT to assess a nutritional intervention on brain development in infants born before 30 weeks — [trial protocol]View study →}.

Gap: no RCT has tested UMP alone against placebo for cognition, memory, or focus in healthy adults — the entire consumer use case is built by extrapolating from aged-rodent neurochemistry and from disease-population combination-product trials, neither of which is a substitute for a trial in the target population.

Mechanisms

Target / pathway	Effect	Relevant to
Kennedy pathway (CDP-choline route)	Uridine → UTP → CTP → CDP-choline, a rate-limiting substrate for phosphatidylcholine synthesis	Membrane/synapse formation, AD trials 11,14Reference 11Agarwal et al. · 2010Short-term administration of uridine increases brain membrane phospholipid precursors in healthy adults: a ³¹P magnetic resonance spectroscopy study at 4T — [MRS study]View study →Reference 14Cansev et al. · 2005Oral uridine-5’-monophosphate (UMP) increases brain CDP-choline levels in gerbils — [gerbil]View study →
Synaptic membrane phospholipids	↑ phosphatidylcholine, synaptic proteins, dendritic spines (with choline + DHA)	Cognitive/AD applications 12,15,19Reference 12De Bruin et al. · 2003AnimalCombined uridine and choline administration improves cognitive deficits in spontaneously hypertensive rats — [rat]View study →Reference 15Wurtman et al. · 2006Synaptic proteins and phospholipids are increased in gerbil brain by administering uridine plus docosahexaenoic acid — [gerbil]View study →Reference 19Wurtman et al. · 2009ReviewSynapse formation is enhanced by oral administration of uridine and DHA, the circulating precursors of brain phosphatides — [review/gerbil]View study →
Striatal dopaminergic signaling	↑ potassium-evoked dopamine release; modulates dopamine-receptor expression	Proposed nootropic/mood effects 16,21Reference 16Wang et al. · 2005AnimalDietary uridine-5’-monophosphate supplementation increases potassium-evoked dopamine release and promotes neurite outgrowth in aged rats — [rat]View study →Reference 21Wang et al. · 2018AnimalAntiepileptic effect of uridine may be caused by regulating dopamine release and receptor expression in corpus striatum — [mouse]View study →
Cholinergic signaling	↑ acetylcholine level and release in striatum (aged rats)	Cognitive applications 17Reference 17Wang et al. · 2007AnimalDietary supplementation with uridine-5’-monophosphate increases acetylcholine level and release in striatum of aged rats — [rat]View study →
Mitochondrial bioenergetics (as TAU)	↑ brain pH, suggestive of improved oxidative phosphorylation	Bipolar depression pilot 10Reference 10Jensen et al. · 2008Triacetyluridine (TAU) decreases depressive symptoms and increases brain pH in bipolar patients — [open-label pilot]View study →

Pharmacokinetics

Free oral uridine is absorbed inconsistently and is subject to rapid first-pass breakdown by uridine phosphorylase in the gut and liver, which is part of why it performs poorly as a standalone oral supplement and why manufacturers favor UMP or the acetylated prodrug triacetyluridine (TAU/PN401). In a phase I oncology pharmacokinetic study, TAU was used as a “uridine rescue” agent for fluorouracil specifically to sustain plasma uridine levels — a design that only makes sense because free uridine itself does not reliably sustain plasma levels at oral doses ^{9Reference 9Kelsen et al. · 1997Clinical trialPhase I trial of PN401, an oral prodrug of uridine, to prevent toxicity from fluorouracil in patients with advanced cancer — [phase I trial]View study →}. Animal comparative work found acetylated prodrugs dramatically outperform the parent molecule: oral TAU at 2000 mg/kg increased plasma uridine by over 250-fold, and a uridine-phosphorylase inhibitor could amplify this further ^{13Reference 13Ashour et al. · 2000AnimalEffect of a uridine-phosphorylase inhibitor on plasma uridine released from 2’,3’,5’-tri-O-acetyluridine, a prodrug of uridine — [mouse PK]View study →}. In the human Souvenaid trials, sustained daily intake did measurably raise circulating uridine, with uptake observed within 6 weeks and a plateau during prolonged intake ^{24Reference 24Rijpma et al. · 2015RCTEffects of Souvenaid on plasma micronutrient levels and fatty acid profiles in mild and mild-to-moderate Alzheimer’s disease — [pooled RCT/OLE analysis]View study →} — indicating that oral UMP as formulated in the medical food does reach the circulation over sustained dosing, even though a single dose of the free nucleoside is poorly absorbed. There is no established elimination half-life for UMP itself in humans; it functions as a circulating precursor pool rather than a drug with a classical pharmacokinetic profile.

Clinical trials

Registered trial activity is heavily weighted toward the multi-ingredient Souvenaid/Fortasyn Connect product and toward oncology uses of related uridine-rescue prodrugs (TAU/PN401), rather than isolated UMP as a nootropic; almost no trials test UMP alone in healthy adults.

Completed	Recruiting	Active, not recruiting	Terminated	Withdrawn
2 (Souvenaid-specific)	0	1	0	0

Last checked: July 2026.

Dietary Sources

UMP is not a supplement-only synthetic compound — it and related nucleotides are naturally present in food as components of cellular RNA and free nucleotides, and the body also synthesizes uridine nucleotides de novo (via the pyrimidine synthesis pathway) and through salvage of dietary and cellular RNA breakdown products. So dietary intake supplements — rather than uniquely supplies — the body’s uridine pool.

Source	Notes
Human breast milk	Contains measurable UMP as one of several free nucleotides; one HPLC analysis of Chinese breast milk found a median UMP level of roughly 9 mg/L, alongside CMP, GMP and AMP 25Reference 25Zhang et al. · 2022Profile of nucleotides in Chinese mature breast milk from six regions — [food-composition analysis]View study →.
Organ meats, yeast, and other RNA-rich foods	High cellular-turnover tissues and yeast are rich in RNA, which is broken down to free nucleotides (including UMP) during digestion.
Beer and fermented foods	Yeast-derived nucleotides contribute to the purine/pyrimidine content of beer and other fermented products.
Infant formula (fortified)	Several formulas are fortified with a defined blend of nucleotides (CMP, UMP, AMP, GMP, IMP) to approximate breast-milk nucleotide content 26,27Reference 26Determination of nucleotides in infant f · 2008Determination of nucleotides in infant formula by ion-exchange liquid chromatography (2008) — [analytical method]. Journal of Agricultural and Food Chemistry. https://pubmed.ncbi.nlm.nih.gov/18642838/View study →Reference 27Effective et al. · 2022Effective and repeatable chromatographic separation of 5 nucleotides in infant formula milk powder by ion-pair HPLC-UV (2022) — [analytical method]. Journal of Dairy Science. https://pubmed.ncbi.nlm.nih.gov/35181132/View study →.
Cow’s milk	Contains substantially fewer nucleosides/nucleotides than human milk — bovine milk-based infant formula historically required nucleotide fortification for this reason 28Reference 28Profile of nucleotides et al. · 1995Profile of nucleotides and nucleosides of human milk (includes a bovine-milk comparison) (1995) — [food-composition analysis]. Journal of Nutritional Science and Vitaminology (Tokyo). https://pubmed.ncbi.nlm.nih.gov/8676214/View study →.

Supplemental UMP itself is manufactured (typically via fermentation or chemical synthesis), not extracted from food — the dietary-sources discussion here concerns the body’s broader uridine/nucleotide economy rather than a food source of concentrated supplemental UMP.

Dosage & Intake

There is no RDA, AI, or established Tolerable Upper Intake Level for UMP — it is not classified as an essential nutrient, since the body can synthesize pyrimidine nucleotides de novo. Studied ranges differ by context:

• Standalone nootropic use (as marketed): 150–300 mg/day is the typical commercial dosing — but this range is not the dose tested in any placebo-controlled human trial of UMP alone; it derives from supplement-industry convention, not a clinical dose-finding study.
• As one ingredient of the Fortasyn Connect medical food (Souvenaid): the studied product delivers UMP alongside choline, EPA/DHA, phospholipids, and B-vitamin cofactors in a 125 mL once-daily drink; the UMP contribution is proprietary and not separately dosed in the published trials ^{1,2,3,4,5,6,7,8Reference 1Scheltens et al. · 2010RCTEfficacy of a medical food in mild Alzheimer’s disease: a randomized, controlled trial — [RCT]View study →Reference 2Scheltens et al. · 2012RCTEfficacy of Souvenaid in mild Alzheimer’s disease: results from a randomized, controlled trial — [RCT]View study →Reference 3Shah et al. · 2013RCTThe S-Connect study: results from a randomized, controlled trial of Souvenaid in mild-to-moderate Alzheimer’s disease — [RCT, null]View study →Reference 4Soininen et al. · 2017RCTSoininen, H., Solomon, A., Visser, P. J., et al. (2017). 24-month intervention with a specific multinutrient in people with prodromal Alzheimer’s disease (LipiDiDiet): a randomised, double-blind, controlled trial — [RCT]. The Lancet Neurology. https://pubmed.ncbi.nlm.nih.gov/29097166/View study →Reference 5Soininen et al. · 2021RCTSoininen, H., Solomon, A., Visser, P. J., et al. (2021). 36-month LipiDiDiet multinutrient clinical trial in prodromal Alzheimer’s disease — [RCT]. Alzheimer’s & Dementia. https://pubmed.ncbi.nlm.nih.gov/32920957/View study →Reference 6Hendrix et al. · 2023RCTCombined evidence for a long-term, clinical slowing effect of multinutrient intervention in prodromal Alzheimer’s disease: post-hoc analysis of 3-year LipiDiDiet data — [post-hoc RCT analysis]View study →Reference 7Burckhardt et al. · 2020Systematic reviewSouvenaid for Alzheimer’s disease — [Cochrane systematic review]View study →Reference 8Thunborg et al. · 2024RCTIntegrating a multimodal lifestyle intervention with medical food in prodromal Alzheimer’s disease: the MIND-ADmini randomized controlled trial — [RCT, pilot]View study →}.
• As triacetyluridine (a more bioavailable prodrug, not UMP itself): doses up to 18 g/day have been used in small psychiatric pilot studies — far higher than typical UMP supplementation and not directly comparable ^{10Reference 10Jensen et al. · 2008Triacetyluridine (TAU) decreases depressive symptoms and increases brain pH in bipolar patients — [open-label pilot]View study →}.
• Mechanistic/MRS dosing (free uridine, not UMP): 2 g/day for 7 days was used to demonstrate brain phospholipid-precursor changes in healthy men ^{11Reference 11Agarwal et al. · 2010Short-term administration of uridine increases brain membrane phospholipid precursors in healthy adults: a ³¹P magnetic resonance spectroscopy study at 4T — [MRS study]View study →}.

These are doses studied in research, not a personal recommendation — and note that the commercial 150–300 mg/day nootropic range specifically has not itself been validated in a controlled human trial. UMP is typically taken with choline and DHA sources, reflecting the “three-precursor” mechanistic hypothesis rather than a proven absorption interaction.

Safety

The clinical safety record for UMP comes almost entirely from Souvenaid/Fortasyn Connect trials, where UMP is one of several ingredients — reported adverse-event rates in these trials were low and similar between active and control groups, and the largest trial (mild-to-moderate AD, S-Connect) reported no clinically relevant differences in blood safety parameters after 24 weeks ^{3Reference 3Shah et al. · 2013RCTThe S-Connect study: results from a randomized, controlled trial of Souvenaid in mild-to-moderate Alzheimer’s disease — [RCT, null]View study →}. No trial has reported a UMP-specific adverse signal. However, because UMP has essentially never been tested alone in a rigorous human trial, standalone safety data — outside the multi-ingredient medical food — are sparse, and no dedicated dose-escalation or long-term tolerability study of isolated UMP in healthy adults has been published.

• Interactions: No well-characterized drug interactions have been established for UMP specifically. As a pyrimidine nucleotide, theoretical caution applies with drugs that affect nucleotide/nucleoside metabolism (e.g. the chemotherapy agent 5-fluorouracil, which is metabolically linked to the pyrimidine pathway and for which uridine prodrugs have specifically been studied as a rescue agent ^{9Reference 9Kelsen et al. · 1997Clinical trialPhase I trial of PN401, an oral prodrug of uridine, to prevent toxicity from fluorouracil in patients with advanced cancer — [phase I trial]View study →}) — this is not evidence of harm from ordinary supplemental use, but reflects genuine overlap in the same metabolic pathway.
• Who should be cautious: people on fluoropyrimidine chemotherapy (given the mechanistic overlap with uridine rescue strategies) and those with rare inherited disorders of pyrimidine metabolism (e.g. hereditary orotic aciduria, itself historically treated with uridine) should discuss supplementation with their prescriber.

Pregnancy & lactation

Verdict: not established as safe — avoid supplemental use without medical advice. No human pregnancy or lactation trials of supplemental UMP exist. UMP-related nucleotides occur naturally in breast milk, but that is a fact about normal milk composition, not evidence that supplemental UMP is safe to add during pregnancy or lactation.

Scope of this safety review (for honesty, not a claim):

• Interactions assessed? Partially — only the theoretical overlap with pyrimidine/nucleotide-metabolism drugs (fluoropyrimidine chemotherapy) was identified; no systematic interaction screen for isolated UMP exists in the literature.
• Pregnancy/lactation assessed? No — no human supplemental-use data exist; only normal breast-milk nucleotide content has been characterized.
• Upper Limit? No UL set for UMP. Absence of an established UL does not imply unlimited supplemental intake is safe — it reflects the lack of dedicated toxicology and dose-finding studies in isolated UMP.

References