Citicoline (INN), also known as cytidine diphosphate-choline (CDP-Choline) or cytidine 5'-diphosphocholine is an intermediate in the generation of phosphatidylcholine from choline, a common biochemical process in cell membranes.
Citicoline is naturally occurring in the cells of human and animal tissue, in particular the organs.
Studies suggest that CDP-choline supplements increase dopamine receptor densities. Intracerebroventricular administration of Citicoline has also been shown to elevate ACTH independently from CRH levels and to amplify the release of other HPA axis hormones such as LH, FSH, GH and TSH in response to hypothalamic releasing factors.
These effects on HPA hormone levels may be beneficial for some individuals but may have undesirable effects in those with medical conditions featuring ACTH or cortisol hypersecretion including PCOS, type II diabetes and major depressive disorder.
Use as a dietary supplement
Citicoline is available as a supplement in over 70 countries under a variety of brand names: Cebroton, Ceraxon, Cidilin, Citifar, Cognizin, Difosfocin, Hipercol, NeurAxon, Nicholin, Sinkron, Somazina, Synapsine, Startonyl, Trausan, Xerenoos, etc. When taken as a supplement citicoline is hydrolyzed into choline and cytidine in the intestine. Once these cross the blood–brain barrier it is reformed into citicoline by the rate-limiting enzyme in phosphatidylcholine synthesis, CTP-phosphocholine cytidylyltransferase. 