Citicoline (CDP-Choline)
A choline/cytidine compound used as a nootropic and, historically, as a stroke and dementia therapy. It has a relatively large human trial base, though results for acute stroke were disappointing; it is generally well tolerated.
01 Overview
Citicoline (cytidine-5'-diphosphocholine) is an intermediate in phosphatidylcholine synthesis. It supplies both choline (for acetylcholine) and cytidine (converted to uridine), and has been studied extensively for ischaemic stroke, vascular cognitive impairment, and glaucoma.
Large acute-stroke trials such as ICTUS did not show benefit, tempering enthusiasm, but citicoline remains used as a supplement and prescription nootropic in several countries with a good tolerability record.
02 Mechanism
Provides substrate for phosphatidylcholine membrane synthesis and for acetylcholine; the cytidine/uridine component may support neuronal membrane and dopaminergic function.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common | 250–500 mg/day | Oral | |
| Therapeutic | 500–2000 mg/day | Oral | Stroke/dementia trials used up to 2000 mg/day. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Attention and memory supportImproved attention measures in some trials of older adults and healthy volunteers. | Small-moderate | Clinical | |
| Choline and membrane supportRaises choline availability with cleaner tolerability than some alternatives. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Gastrointestinal upsetNausea or diarrhoea reported infrequently in trials. | Mild | Uncommon | Clinical | |
| Insomnia or headacheSome users report activation or headache. | Mild | Uncommon | Anecdotal |