# Uridine

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/uridine
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-28
**Evidence Score:** 2 / 10
**Category:** Compound
**Also Known As:** 1-β-D-Ribofuranosyluracil, Uridine nucleoside, β-Uridine, UdR, Urd

## Overview

Uridine is a pyrimidine nucleoside that serves as a precursor to RNA synthesis and plays a central role in phosphatidylcholine biosynthesis via the Kennedy pathway. It supports neuronal membrane formation, synaptic plasticity, and [dopamine](/ingredients/condition/mood)rgic signaling by increasing dendritic spine density and modulating P2 purinergic receptors.

## Health Benefits

• May reduce depression symptoms in adolescents with bipolar disorder - open-label study (n=7) showed CDRS-R score reduction from 65.6 to 27.2 after 6 weeks (preliminary evidence)
• Effective for neuralgic pain when combined with cytidine and vitamin B12 - RCT (PMID: 28243144) found combination as effective as diclofenac (moderate evidence)
• Reduces low back pain in combination therapy - RCT (PMID: 33116795) showed nucleotide combination superior to B vitamins + diclofenac (moderate evidence)
• Protects against [mitochondrial](/ingredients/condition/energy) neurotoxicity from nucleoside analogues - animal studies (PMID: 20032772) demonstrate [neuroprotective effect](/ingredients/condition/cognitive)s (preliminary evidence)
• Supports synaptic membrane formation and neuronal repair through phospholipid synthesis pathways (mechanistic evidence)

## Mechanism of Action

Uridine crosses the blood-brain barrier and is phosphorylated to UTP, which enters the Kennedy pathway to synthesize phosphatidylcholine, a key neuronal membrane phospholipid. It upregulates [dopamine](/ingredients/condition/mood) receptor density and enhances synaptic signaling by increasing dendritic spine formation, partly through activation of P2Y and P2X purinergic receptors. Additionally, uridine serves as a substrate for cytidine diphosphate-choline (CDP-choline) synthesis, directly supporting neuronal membrane integrity and repair.

## Clinical Summary

A small open-label study (n=7) in adolescents with bipolar depression showed uridine supplementation reduced Children's Depression Rating Scale-Revised (CDRS-R) scores from 65.6 to 27.2 over 6 weeks, though the lack of a control group limits conclusions. A randomized controlled trial (PMID: 28243144) demonstrated that a combination of uridine, cytidine, and vitamin B12 was effective in reducing neuralgic pain, providing stronger evidence for peripheral nerve applications. Preclinical rodent studies show uridine increases dendritic spine density and enhances [cognitive performance](/ingredients/condition/cognitive) when combined with choline and DHA, forming the basis of the Souvenaid formulation studied in Alzheimer's disease. Overall, evidence in humans remains preliminary to moderate depending on the indication, with larger placebo-controlled trials needed.

## Nutritional Profile

Uridine is a pyrimidine nucleoside (molecular weight: 244.2 g/mol) composed of uracil linked to ribose. It is not a traditional macronutrient or micronutrient but a bioactive compound. Typical supplemental doses range from 500–1000 mg/day. Endogenous plasma concentrations in humans are approximately 3–8 µmol/L under fasting conditions. Dietary sources include beer (0.05–1.0 mg/mL), brewer's yeast, liver, fish, broccoli, and tomatoes, though concentrations are generally low. As a free nucleoside, oral bioavailability is estimated at roughly 5–10% due to extensive first-pass [metabolism](/ingredients/condition/weight-management); hepatic phosphorylation and incorporation into RNA limit systemic availability. Triacetyluridine (TAU), a prodrug form, has significantly higher bioavailability (~6–7× compared to uridine). Uridine participates in the CDP-choline (Kennedy) pathway, contributing to phosphatidylcholine and membrane phospholipid synthesis. It serves as a precursor to UTP and CTP, nucleotides critical for glycosylation reactions and RNA synthesis. No established Dietary Reference Intake (DRI) exists. It contains negligible caloric value as typically supplemented. Synergistic effects observed with cytidine and vitamin B12 in neurological applications (as referenced in combination RCT evidence). No significant fat, protein, or carbohydrate content in pure compound form.

## Dosage & Preparation

Clinically studied oral dosage: 500 mg twice daily (total 1 g/day) as powder or capsule for bipolar depression in adolescents (6 weeks duration). For neuralgic and low back pain, uridine is used in standardized combinations with cytidine and vitamin B12, though specific doses were not detailed in trials. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Uridine is generally well tolerated at supplemental doses of 500–1000 mg/day, with mild gastrointestinal side effects such as nausea or loose stools reported in some users. It may interact with anticonvulsants, particularly capecitabine and fluorouracil-based chemotherapy drugs, as uridine is a metabolic competitor with these fluoropyrimidine compounds and can reduce their efficacy. Individuals with hereditary orotic aciduria or certain urea cycle disorders should use uridine only under medical supervision. Safety data in pregnancy and lactation are insufficient, and use is not recommended in those populations without physician guidance.

## Scientific Research

Clinical evidence includes an ongoing RCT (NCT01805440) testing 500mg twice daily in adolescents with bipolar depression, and completed trials showing efficacy for neuralgic and low back pain when combined with cytidine and B12 (PMIDs: 28243144, 33116795). An open-label case series (n=7) demonstrated significant depression score improvements, though no meta-analyses have been conducted to date.

## Historical & Cultural Context

No historical traditional medicine use was identified in the research sources. Uridine research is entirely modern, focused on biomedical supplementation rather than ethnobotanical or ancient medicine systems.

## Synergistic Combinations

Cytidine, Vitamin B12, Choline, DHA, Gabapentin

## Frequently Asked Questions

### What is the recommended dosage of uridine supplement?

Most human studies and clinical protocols use uridine monophosphate (UMP) at doses ranging from 500 mg to 1000 mg per day, often taken with a meal to improve absorption. The Souvenaid clinical trials used 625 mg of UMP daily in combination with choline and DHA, and this stack has the most robust human data for cognitive applications.

### Does uridine help with depression?

A preliminary open-label study in 7 adolescents with bipolar depression found that 500 mg/day of uridine for 6 weeks reduced CDRS-R depression scores from an average of 65.6 to 27.2, suggesting a meaningful antidepressant effect. However, without a placebo control group and given the very small sample size, these results are considered early-stage evidence and should not replace standard psychiatric treatment.

### What is the difference between uridine and CDP-choline (citicoline)?

Citicoline (CDP-choline) is metabolized in the gut and plasma into cytidine and choline, and cytidine is subsequently converted to uridine in the brain, meaning both supplements ultimately elevate brain uridine levels. Uridine monophosphate supplementation bypasses this conversion step and may more directly raise plasma uridine, though citicoline also simultaneously delivers choline, making it a dual-action nootropic with additional acetylcholine support.

### Can uridine be taken with choline and DHA together?

Yes, the combination of uridine, choline, and DHA (docosahexaenoic acid) is sometimes called the 'trisynaptic stack' and is supported by animal research showing synergistic increases in dendritic spine density and phosphatidylcholine synthesis beyond what any single compound achieves alone. The Souvenaid formula, tested in multiple Alzheimer's disease trials, is based on this exact combination, with the largest study (LipiDiDiet RCT) showing slowed brain atrophy in prodromal Alzheimer's patients over 24 months.

### Does uridine interact with any medications?

Uridine can competitively interfere with fluoropyrimidine chemotherapy drugs such as 5-fluorouracil (5-FU) and capecitabine, as these agents work by mimicking uridine and disrupting RNA synthesis in cancer cells; co-administration may reduce their therapeutic efficacy. Uridine triacetate (a pharmaceutical form) is actually FDA-approved as an antidote to 5-FU overdose for this exact reason, highlighting the clinical significance of this interaction.

### What does clinical research show about uridine for pain management?

Uridine has demonstrated moderate evidence for pain relief when combined with cytidine and vitamin B12, with one randomized controlled trial showing this combination was as effective as the prescription medication diclofenac for neuralgic pain. Additionally, uridine has been studied in combination therapies for reducing low back pain, though more research is needed to establish optimal dosing and which pain conditions respond best. Most evidence currently supports uridine as part of a multi-ingredient formula rather than as a standalone treatment for pain.

### Who should consider taking uridine supplements based on current evidence?

Individuals interested in cognitive support and brain health may benefit from uridine, particularly when combined with choline and omega-3 fatty acids as part of a comprehensive stack. People experiencing chronic pain conditions, especially neuralgic or lower back pain, may explore uridine-based combination supplements, though results are more established when combined with cytidine and B vitamins. Those with mood concerns should consult a healthcare provider, as preliminary evidence suggests potential benefits for certain populations, but research remains limited to small studies.

### Is uridine safe for long-term supplementation?

Uridine is generally recognized as safe for supplementation at standard dosages, as it is a naturally occurring nucleobase found in the body and dietary sources. However, long-term safety data is limited compared to more extensively studied supplements, so extended use should ideally be discussed with a healthcare provider. No serious adverse events have been reported in clinical trials at recommended doses, though individual tolerance may vary.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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