Glycerophosphocholine (GPC), commonly known as alpha-GPC, is a naturally occurring choline compound found in the brain. There is scientific evidence supporting its use for supporting the "Specific Neurotransmitters" body system, particularly in relation to acetylcholine, a key neurotransmitter involved in memory, learning, and other cognitive functions. Alpha-GPC serves as a precursor to acetylcholine synthesis in the brain. Multiple randomized, controlled trials—primarily conducted in older adults with cognitive decline or dementia—have shown that alpha-GPC supplementation may improve memory, attention, and other cognitive measures. For example, a review published in Clinical Therapeutics (2003) concluded that alpha-GPC had significant positive effects on cognitive function in patients with Alzheimer's disease and vascular dementia compared to placebo.

Mechanistically, GPC increases the availability of choline for acetylcholine production in neurons. This supports neurotransmission and may counteract deficits seen in neurodegenerative diseases. While the strongest evidence is in populations with cognitive impairment, some small studies suggest possible cognitive or neuroprotective benefits in healthy adults as well, though results are less robust.

In summary, the scientific literature provides moderate to strong evidence that GPC supports the function of specific neurotransmitters (primarily acetylcholine), justifying its use for this body system, especially in the context of cognitive decline.