Citicoline (CDP-Choline)

What it is

Citicoline stands for cytidine 5′-diphosphocholine. The body makes it itself as an intermediate step in the synthesis of phosphatidylcholine, the main component of many cell membranes. When taken orally, it is split into choline and cytidine. Choline is the building block of the neurotransmitter acetylcholine; cytidine is converted in the body to uridine and also feeds into membrane synthesis.

Medicines containing citicoline have been prescribed in several countries since the 1970s, as a nootropic and for the consequences of brain diseases. In the EU, the inner-salt form has been authorized as a novel food since 2014. In nootropic stacks it is, alongside alpha-GPC, the most popular source of choline.

How it is supposed to work

The basic idea: acetylcholine underpins attention and memory, and choline is its building block. More building block, so the hope goes, means more neurotransmitter and a clearer head. With citicoline a second strand is added: it supports the synthesis of membrane lipids in nerve cells.

This second effect has been measured in humans. In a magnetic resonance spectroscopy study with 16 healthy adults, after 6 weeks phosphocreatine in the anterior frontal brain rose by 7 percent, high-energy nucleoside triphosphates by 14 percent and the ratio of phosphocreatine to inorganic phosphate by 32 percent, and membrane components changed as well. This shows that citicoline reaches the brain and alters metabolism there. Whether better cognitive performance follows from this is another question.

User reports

In nootropics circles, a noticeably clearer head is consistently described, often within days. A 2014 survey by the US blog Slate Star Codex in the two largest nootropics forums gives a rough measure of this. Of 162 respondents, 92 percent men, with an average age of 25, users rated citicoline at an average of 5.37 out of 10 points, alpha-GPC at 5.07 and the simple choline salt choline bitartrate at 3.7. The author took the value for the choline salt, which barely reaches the brain, as a rough measure of the placebo effect.

Citicoline was thus a good point higher, with 19 users. The author himself named two explanations: either the forms that reach the brain work better, or users know which form is supposed to be the better one. The question about choline against headaches with racetams is also revealing: 40 percent said it helps, 26 percent that it does not help, and 34 percent took it because everyone recommends it. These are reports without placebo control, not proof of efficacy — but they show what users are looking for: drive and a clear head.

Citicoline or alpha-GPC

Both supply choline, both reach the brain, and citicoline additionally supplies cytidine. There is no direct comparison in a controlled study. Korean insurance data provide contradictory observations on stroke risk for alpha-GPC. This discussion concerns alpha-GPC, not citicoline. For citicoline, on the other hand, there is the large stroke study, which showed neither benefit nor harm.

What the studies show

Stroke: ICTUS (Lancet 2012)

Dávalos and colleagues randomized 2,298 patients with moderate to severe acute stroke at hospitals in Spain, Portugal and Germany to citicoline or placebo, starting within 24 hours, for 6 weeks. The trial was stopped for futility at the third interim analysis. Global recovery after 90 days was the same in both groups (odds ratio 1.03; 95 percent confidence interval 0.86 to 1.25). An earlier pooled analysis of smaller studies had suggested a benefit.

Memory in older age (Journal of Nutrition 2021)

Nakazaki and colleagues gave 100 healthy people aged 50 to 85 with age-related memory complaints 500 milligrams of citicoline daily or placebo for 12 weeks. The primary endpoint, a spatial memory span test, showed only a trend. In the secondary endpoints, episodic memory and an overall memory score improved significantly more than under placebo. Sponsored by the manufacturer.

Brain metabolism (NMR in Biomedicine 2008)

Silveri and colleagues examined 16 healthy adults before and after 6 weeks of citicoline using phosphorus spectroscopy. In the anterior cingulate gyrus, high-energy phosphates rose and membrane components changed. There was no placebo group.

Where the data stop

For the use that is most heavily advertised, a clearer head in healthy people, the data are thin. In 2024 the EFSA reviewed an application for a health claim on memory and rejected it. Only one randomized study in healthy people showed an advantage in episodic memory, a further study over 3 months found none, and data from dementia studies did not support the effect. The panel also saw no convincing mechanism by which citicoline should improve memory beyond the body’s own production.

In addition: the positive studies in healthy people are small, short and almost all paid for by the manufacturer, and the findings often come from secondary endpoints. And in stroke, the indication for which it is approved as a medicine in some countries, the largest study to date showed no benefit.

Status, approval and legal

In Germany, citicoline is sold mainly as a food supplement. The EU authorized it as a novel food in 2014: in food supplements for middle-aged and older adults at a maximum of 500 milligrams per day, in foods for special medical purposes at a maximum of 250 milligrams per serving and 1,000 milligrams per day. A health claim on memory is not authorized. In some other countries citicoline is a medicine, among other things for acute stroke. Citicoline is not on the doping list. The studies in healthy people used 250 to 500 milligrams daily, the stroke study considerably more.

Safety

Citicoline is considered well tolerated. In the ICTUS trial there were no differences in safety endpoints, mortality or side-effect rates compared with placebo, including brain hemorrhages after thrombolysis. The EU authorization as a food is aimed at middle-aged and older adults; for children and pregnant or breastfeeding women there is no data basis. Anyone who has had a stroke, has another neurological disease or takes medication should discuss taking it with a physician.

Sources

• Dávalos et al., Lancet 2012 (ICTUS)
• Nakazaki et al., J Nutr 2021
• McGlade et al., J Atten Disord 2019
• Silveri et al., NMR Biomed 2008
• EFSA NDA Panel, EFSA J 2024: citicoline and memory
• Synoradzki and Grieb, Nutrients 2019
• Alexander, Nootropics Survey Results and Analysis, 2014