Small randomized trials on attention have tested Cognizin, a branded form of citicoline. This guide covers what it is, what those studies found and the doses they used.
Cognizin, a branded form of citicoline (CDP-choline), comes from Kyowa Hakko Bio. Reported attention gains at 250 to 500 mg a day come from small randomized trials, mostly supported by the ingredient maker. The choline in citicoline matters because the body turns it into the neurotransmitter acetylcholine and into phosphatidylcholine, a building block of cell membranes.
Cognizin is Kyowa Hakko Bio's brand of citicoline (cytidine diphosphate-choline). In the body, this water-soluble compound splits into choline and cytidine. Choline goes into phosphatidylcholine, a major phospholipid of brain cell membranes, and into acetylcholine, a neurotransmitter involved in memory and attention.
Studies of Cognizin are small randomized trials, and the maker supported most of them. In the best known, McGlade et al. (2012), healthy adult women were given a placebo or 250 mg or 500 mg of citicoline daily. Those taking citicoline did better on an attention task. We'd call this promising but limited, since large trials from outside the maker haven't confirmed it.
BrainPill holds 250 mg of Cognizin in each two-capsule serving, a dose inside the range the citicoline studies used. Some other nootropics rely on generic citicoline or on other sources of choline, such as choline bitartrate or Alpha GPC. These are different compounds, and findings for one don't automatically apply to another. As for BrainPill's own trial, the company sponsored it, it is unpublished and only a subgroup did better.