Citicoline (CDP-choline)

What it is

Citicoline, also called CDP-choline, is a compound the body makes naturally as part of building cell membranes. When swallowed it splits into choline and cytidine, which the body then uses.

In some countries it is a prescription medicine for stroke recovery and cognitive problems. In the UK and many other places it is sold as a food supplement for focus and memory.

How it works

Citicoline supplies choline (for acetylcholine and membrane phospholipids) and cytidine (converted to uridine). Both are thought to support brain cell membranes and signalling. The brain effects in healthy people are less well proven than the chemistry suggests.

What the evidence says

• Moderate Attention and episodic memory in healthy adults
  Small placebo-controlled trials report modest gains in attention and memory at 250 to 500 mg, with effect sizes that are small.
• Limited Age-related memory decline
  Some trials in older adults show benefits, but studies vary in quality.
• Limited Stroke recovery support (medical use)
  Large trials such as ICTUS did not show clear benefit; this is a medical use and not a supplement claim.
• Weak Eye health in glaucoma
  Early research only.

Evidence ratings are our plain-English summary of how much good human research exists, not a promise of results. How we rate evidence.

Dosage and timing

• Commonly 250 to 500 mg a day in supplement trials.
• Take in the morning; taking it late may affect sleep in some people.
• Can be taken with or without food.
• Medical doses are higher and given by clinicians; do not copy those yourself.

Forms and what to look for

• Citicoline sodium is the usual supplement form.
• Branded forms such as Cognizin are used in many studies and carry quality claims.
• Alpha-GPC and choline bitartrate are other choline sources but behave differently.
• Check the label states the amount of citicoline and not the whole capsule.

What to expect, and when

• Some small studies show effects on attention tests within hours or days.
• Memory effects, if present, take several weeks.
• Many people feel nothing noticeable.

Side effects

• Headache, nausea or diarrhoea.
• Insomnia, restlessness or dizziness.
• Blurred vision or low blood pressure in rare cases.
• Stomach discomfort at higher doses.

Interactions

• Possible additive effects with cholinesterase inhibitors such as donepezil.
• May interact with levodopa; reports suggest it can increase its effect, so ask a clinician if you take it.
• Choline sources stacked together can add up and cause side effects.
• May interact with other drugs affecting the nervous system; ask a pharmacist.

Who should avoid it

• Pregnancy and breastfeeding, due to limited data.
• People taking levodopa or dementia medicines without medical advice.
• Anyone with low blood pressure issues.
• People with a history of stroke or significant heart conditions should check with their doctor.

Risks and safety

• Long-term safety data in healthy people is limited, though it is used as a medicine in some countries.
• Product quality varies between suppliers.
• Not currently on the WADA list to our knowledge.

Buying well: quality and testing

• Look for a clear statement of citicoline content per capsule.
• Branded ingredients with published research are easier to compare with trials.
• Prefer third-party tested products.
• Avoid proprietary blends and very low doses.

Bottom line

Citicoline is one of the better-supported brain supplements in terms of small human trials, though effects are modest. It suits people who want a choline source and a gentle possible edge in attention, with realistic expectations. It is not a treatment for memory loss, and anyone worried about memory should see a GP.