300–600 mg/day for cognition; 600 mg before training for strength and power.
May increase power and strength when taken before training.
View the study (RCT) →Some benefit in vascular impairment or Alzheimer's, with older studies.
View the study (RCT) →⏱ 2 min read
Alpha-GPC, or alpha-glycerylphosphorylcholine, is one of the forms of choline with the best brain bioavailability available as a supplement: unlike choline bitartrate or choline chloride (the cheapest forms and the most widely used in fortified foods), alpha-GPC efficiently crosses the blood-brain barrier and is rapidly incorporated into the brain pool of phospholipids and into the immediate precursor for the synthesis of acetylcholine, a neurotransmitter key to memory, learning, attention, and motor function.
Its clinical profile has been studied in three main areas with different degrees of evidence: cognitive impairment associated with cerebrovascular disease and mild Alzheimer's disease, where it is approved as a medication in some European countries such as Italy; cognitive and athletic performance in healthy adults, where the data are more preliminary but interesting; and the acute release of growth hormone, a peculiar pharmacological property exploited by pre-workout supplements.
The indication with the most evidence is mild to moderate cognitive impairment of vascular or degenerative origin: several European trials have shown significant improvements on standardized cognitive scales at doses of 1,200 milligrams per day for 3-6 months, with a clinically relevant efficacy profile and better tolerability than some pharmacological acetylcholinesterase inhibitors.
An Italian trial published in 2003 with more than 2,000 patients (the ASCOMALVA study and others from the same group) confirmed significant improvements on the MMSE and on functional scales with alpha-GPC added to standard donepezil treatment in mild to moderate Alzheimer's disease; these data are the basis for its use as a medication (Gliatilin, Brezal) in several European countries for specific cognitive indications.
In healthy adults, several small studies have shown acute improvements in processing speed, sustained attention, and working memory with single doses of 400-600 milligrams, especially in demanding tasks that require prolonged maintenance of attention; the effects are modest and depend on baseline context, but are consistent with a cholinergic mechanism.
A peculiar property of alpha-GPC is its ability to induce a transient spike in growth hormone (GH) at high doses (600-1,000 milligrams) taken before exercise, a response documented in several small trials; this effect, together with a possible increase in peak force production, has made alpha-GPC a frequent ingredient in pre-workout supplements aimed at strength athletes, although the clinical translation into long-term improvements in body composition has not been demonstrated.
The doses studied range from 300 to 1,200 milligrams per day, divided into one or two doses; for a cognitive indication, 1,200 mg/day divided into three doses; for athletic performance, 600 mg 60-90 minutes before training; with or without food; the effect on cognition appears gradually and requires weeks for a full evaluation.
Generally well tolerated; the most frequent adverse effects are headache, insomnia (if taken very late), irritability, and, occasionally, mild joint pain; people with depression should use caution because there are preliminary data suggesting that increased cholinergic tone could exacerbate depressive symptoms in vulnerable people; those taking anticholinergics (some antihistamines, tricyclic antidepressants, drugs for incontinence) may experience a pharmacodynamic interaction; in pregnancy and breastfeeding the data are limited, although choline is an essential nutrient during those periods.
Information, not medical advice. Scientific evidence reflects the quality of the studies.